Re: [EVDL] Hybrid battery reconditioning
Michael Ross via EV wrote: There are probably no definitive limits to either battery balancer or BMS... But we call a series of batteries a battery just to be imprecise. There is *definitely* no standard terminology. Sellers take Humpty Dumpty's advice -- When I use a word, Humpty Dumpty said in rather a scornful tone, it means just what I choose it to mean — neither more nor less. :-) Researchers are careful to define their terms. But the general public (and hobby EVers) are pretty loose with their terminology. Terms like battery, cell, volts, amps, amphours, watts, watthours, BMS etc. are misused all the time. To me a BMS also manages charge and discharge cut off, as well as balancing. I suppose it could also have a built in charger, but that is not what I think when someone says, that there BMS. There are notification and warning functions, value readouts, etc. that could also be in a system. A battery balancer that does none of these other things is still a battery balancer to me, but wouldn't be a BMS. There should probably be a cell balancer, and BMS. There are *many* things that should be monitored and managed in a complex battery system with many cells. Some are important (safety)! Others less so (range, life). There are also economic factors, and driver interest (or indifference). A modern ICE is a very complex piece of machinery. A huge number of things need to be monitored and controlled to make it work right. But people are used to all this being hidden, and handled by computers. All the driver is left with is a check engine light. Consumers tend to look at batteries the same way. They want to ignore all that stuff about voltages, currents, amphours, temperatures, balance between cells, etc. Buy a magic black box that hides it all. There are lots of people only too happy to provide such a black box solution. The problem is that you won't *know* if it works (until it's too late). If the previous owner of your car defeated the check engine light, how long before you notice that it's out of oil or antifreeze? And what shape will the engine be in when you *do* find out? -- Don't worry about people stealing your ideas. If your ideas are any good, you'll have to ram them down people's throats. -- Howard Aiken -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
[EVDL] Hybrid battery reconditioning
Has anyone heard of this company, or have any experience with them. http://www.thehybridshop.com/battery-conditioning/how-hybrid-battery-conditioning-works-science/ A friend has a 2005 Ford Escape Hybrid, and his batteries are starting to show signs of old age. To replace the pack at the dealer is $5000 vs. $1000 - $1500 to recondition them. Sounds like voodoo to me, but I have no experience with nickel metal hybrid batteries. Need to know if this is really a viable alternative. Thanks; Dennis Elsberry, MO http://www.evalbum.com/1366 http://evalbum.com/3715 -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/40c8bed3/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
http://batteryuniversity.com/learn/article/how_to_restore_nickel_based_batteries Sent from my iPad On Nov 17, 2014, at 5:57 AM, Pestka, Dennis J via EV ev@lists.evdl.org wrote: Has anyone heard of this company, or have any experience with them. http://www.thehybridshop.com/battery-conditioning/how-hybrid-battery-conditioning-works-science/ A friend has a 2005 Ford Escape Hybrid, and his batteries are starting to show signs of old age. To replace the pack at the dealer is $5000 vs. $1000 - $1500 to recondition them. Sounds like voodoo to me, but I have no experience with nickel metal hybrid batteries. Need to know if this is really a viable alternative. Thanks; Dennis Elsberry, MO http://www.evalbum.com/1366 http://evalbum.com/3715 -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/40c8bed3/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
Paul, They are about the only game in town. I have looked briefly at their web stuff and I think they know what they are doing. They seem to build and/or sell some test equipment - implying some expertise. Tomorrow I am visiting a community college (Blue Ridge in Flat Rock NC) that has a pretty extensive training program for working on Prius. They also work on the battery packs. If he is near there he might get a good deal from BRCC, or lean about trained mechanics. I will ask the people at BRCC what they know about The Hybrid Shop. However, I will be out of cell and internet range until next Monday. You could ask THS what they do for $1500, and see if it makes sense. I believe the check the pack pretty thoroughly, and replace any bad cells - what the means regarding NiMH I do not know. Presumably they would have to balance the pack within some range, reject cells that degrade overall pack function and cycle life, etc. If they are comparing the servicing of the pack to new ones they must be pretty good when it is all done. On Mon, Nov 17, 2014 at 7:06 AM, Paul Dove via EV ev@lists.evdl.org wrote: http://batteryuniversity.com/learn/article/how_to_restore_nickel_based_batteries Sent from my iPad On Nov 17, 2014, at 5:57 AM, Pestka, Dennis J via EV ev@lists.evdl.org wrote: Has anyone heard of this company, or have any experience with them. http://www.thehybridshop.com/battery-conditioning/how-hybrid-battery-conditioning-works-science/ A friend has a 2005 Ford Escape Hybrid, and his batteries are starting to show signs of old age. To replace the pack at the dealer is $5000 vs. $1000 - $1500 to recondition them. Sounds like voodoo to me, but I have no experience with nickel metal hybrid batteries. Need to know if this is really a viable alternative. Thanks; Dennis Elsberry, MO http://www.evalbum.com/1366 http://evalbum.com/3715 -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/40c8bed3/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/da4c61d8/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
From the webpage description, it sounds like they know what they're doing, though I have no way to judge whether they're using appropriate criteria for deciding which modules are defective. Alas, any time you fix a declining EV battery by replacing the worst cells or blocks, rather than all of them, you have no way to know what other cells or blocks might turn toes up next week, next month, or next year. I've done what they describe with lead EV batteries, replacing blocks as they fail. With that situation it's mostly a losing game, because once a couple blocks die, the rest usually aren't far behind. Coincidentally, this is a NiMH question I'm facing too. I have a 36v 10ah NiMH e-bike battery here that's on its last legs. I've been debating whether to (a) replace just the bum cells and see how it goes, (b) replace all the cells, or (c) gut the battery and try lithium cells instead. (Tenergy brand tabbed D-size cells are around $9 each plus shipping; other brands are much more expensive, if you can even find them with tabs.) I'll be interested to hear from anyone who has experience doing this with NiMH in EVs. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
You all need to read the link I posted. It explains how to recondition Nickle based batteries. It also explains the failure mechanism and why this works. From: EVDL Administrator via EV ev@lists.evdl.org To: Electric Vehicle Discussion List ev@lists.evdl.org Sent: Monday, November 17, 2014 9:15 AM Subject: Re: [EVDL] Hybrid battery reconditioning From the webpage description, it sounds like they know what they're doing, though I have no way to judge whether they're using appropriate criteria for deciding which modules are defective. Alas, any time you fix a declining EV battery by replacing the worst cells or blocks, rather than all of them, you have no way to know what other cells or blocks might turn toes up next week, next month, or next year. I've done what they describe with lead EV batteries, replacing blocks as they fail. With that situation it's mostly a losing game, because once a couple blocks die, the rest usually aren't far behind. Coincidentally, this is a NiMH question I'm facing too. I have a 36v 10ah NiMH e-bike battery here that's on its last legs. I've been debating whether to (a) replace just the bum cells and see how it goes, (b) replace all the cells, or (c) gut the battery and try lithium cells instead. (Tenergy brand tabbed D-size cells are around $9 each plus shipping; other brands are much more expensive, if you can even find them with tabs.) I'll be interested to hear from anyone who has experience doing this with NiMH in EVs. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/8634f361/attachment-0001.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
On this topic - reconditioning Prius packs. During the visit I am making tomorrow to the Prius repair classes at Blue Ridge Community College... what questions do you think I should ask them there to see how they are managing their repairs of Prius packs? The answers might be interesting to Dennis Pestka as well. On Mon, Nov 17, 2014 at 10:15 AM, EVDL Administrator via EV ev@lists.evdl.org wrote: From the webpage description, it sounds like they know what they're doing, though I have no way to judge whether they're using appropriate criteria for deciding which modules are defective. Alas, any time you fix a declining EV battery by replacing the worst cells or blocks, rather than all of them, you have no way to know what other cells or blocks might turn toes up next week, next month, or next year. I've done what they describe with lead EV batteries, replacing blocks as they fail. With that situation it's mostly a losing game, because once a couple blocks die, the rest usually aren't far behind. Coincidentally, this is a NiMH question I'm facing too. I have a 36v 10ah NiMH e-bike battery here that's on its last legs. I've been debating whether to (a) replace just the bum cells and see how it goes, (b) replace all the cells, or (c) gut the battery and try lithium cells instead. (Tenergy brand tabbed D-size cells are around $9 each plus shipping; other brands are much more expensive, if you can even find them with tabs.) I'll be interested to hear from anyone who has experience doing this with NiMH in EVs. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/1972f599/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
I have to say, I am wary of The Battery Universit regarding Li ion batteries. I have seen some incorrect information there. Maybe they are fine WRT Prius and NiMH - but I am just sayin'... To me their rep is not pure and unsoiled.. On Mon, Nov 17, 2014 at 11:37 AM, paul dove via EV ev@lists.evdl.org wrote: You all need to read the link I posted. It explains how to recondition Nickle based batteries. It also explains the failure mechanism and why this works. From: EVDL Administrator via EV ev@lists.evdl.org To: Electric Vehicle Discussion List ev@lists.evdl.org Sent: Monday, November 17, 2014 9:15 AM Subject: Re: [EVDL] Hybrid battery reconditioning From the webpage description, it sounds like they know what they're doing, though I have no way to judge whether they're using appropriate criteria for deciding which modules are defective. Alas, any time you fix a declining EV battery by replacing the worst cells or blocks, rather than all of them, you have no way to know what other cells or blocks might turn toes up next week, next month, or next year. I've done what they describe with lead EV batteries, replacing blocks as they fail. With that situation it's mostly a losing game, because once a couple blocks die, the rest usually aren't far behind. Coincidentally, this is a NiMH question I'm facing too. I have a 36v 10ah NiMH e-bike battery here that's on its last legs. I've been debating whether to (a) replace just the bum cells and see how it goes, (b) replace all the cells, or (c) gut the battery and try lithium cells instead. (Tenergy brand tabbed D-size cells are around $9 each plus shipping; other brands are much more expensive, if you can even find them with tabs.) I'll be interested to hear from anyone who has experience doing this with NiMH in EVs. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/8634f361/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/8a1ca03c/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
On Mon, Nov 17, 2014 at 7:06 AM, Paul Dove via EVev@lists.evdl.org wrote: http://batteryuniversity.com/learn/article/how_to_restore_nickel_based_batteries Just be aware that you can take *any* battery and charge it hard to get a (temporary) improvement in its amphour capacity. The problem is that it doesn't last. Hybrids in particular are very careful how they charge and discharge their batteries, to maximize life. Hybrid batteries are considered part of the emission control system, so automakers are required to warrant the battery for 100k miles. This won't happen if you use it hard. -- Obsolete (Ob-so-LETE). Adjective. 1. Something that is simple, reliable, straightforward, readily available, easy to use, and affordable. 2. Not what the salesman wants you to buy. -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
paul dove via EV wrote: You all need to read the link I posted. It explains how to recondition Nickle based batteries. It also explains the failure mechanism and why this works. I did read it, Paul. The Cadex info is old science, and is mainly relevant to old-style nicads from decades ago. The Hybridshop data is 99% marketing eyewash, written to sound wonderful. As I said, *any* battery's capacity will temporarily improve just by cycling it deeper than it is usually cycled. But the improvement won't last. If all you're trying to do is eke a little more life out of a pack, that may be sufficient. But you're paying a high price for that small extension. -- Obsolete (Ob-so-LETE). Adjective. 1. Something that is simple, reliable, straightforward, readily available, easy to use, and affordable. 2. Not what the salesman wants you to buy. -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
EVDL Administrator via EV wrote: Alas, any time you fix a declining EV battery by replacing the worst cells or blocks, rather than all of them, you have no way to know what other cells or blocks might turn toes up next week, next month, or next year. That's true. However, it is also true that the one cell that failed may have been infant mortality. It could have died young due to some quality defect or temporary abuse (like excessively discharging the pack, which killed the weakest cell). If you replace it, you can keep right on using the rest of the pack for an extended period. I've done what they describe with lead EV batteries, replacing blocks as they fail. With that situation it's mostly a losing game, because once a couple blocks die, the rest usually aren't far behind. This is often true because the driver and the battery charger don't *know* there's a problem. For example, if one cell shorts, the charger blindly charges the remaining pack to the full voltage that was needed with all cells good. That overcharges the remaining good cells, driving them into an early grave. Coincidentally, this is a NiMH question I'm facing too. I have a 36v 10ah NiMH e-bike battery here that's on its last legs. I've been debating whether to (a) replace just the bum cells and see how it goes, (b) replace all the cells, or (c) gut the battery and try lithium cells instead. If the original cells were high quality, they would all have been well matched. When one of them fails, the rest may not be far behind because they are all so much alike. For example, I've tested Prius nimh modules; even my 10-year-old ones are as alike as peas in a pod. If the pack is made from el-cheapo cells with negligible quality control, you could easily have a few lemons that died young, and are making the whole pack look bad. For example, I tested a set of ten 12v 7ah batteries from an anonymous Chinese manufacturer in a UPS; 4 were junk, and the remaining 6 varied from 1.7ah to 4.2ah. I was able to replace the 5 worst, and keep using the remaining 5. The only way to know for sure is to TEST. Test each cell or battery, and see what you've got. If they are all low in capacity, then it's time to replace the pack. If only one or two are significantly worse than the rest, replace them and keep going. :-) -- Obsolete (Ob-so-LETE). Adjective. 1. Something that is simple, reliable, straightforward, readily available, easy to use, and affordable. 2. Not what the salesman wants you to buy. -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
Lee said: The only way to know for sure is to TEST. Test each cell or battery, and see what you've got. If they are all low in capacity, then it's time to replace the pack. If only one or two are significantly worse than the rest, replace them and keep going. :-) This was my assumption. I will be interested to see if the school or Hybrid Shop goes to this much trouble. If we were to estimate the labor required to test a Prius pack - what would that look like? Would it be any where near sat $1000? I would like to take a critical eye into these visits, but I have never looked close or far at a Prius pack. mike On Mon, Nov 17, 2014 at 1:33 PM, Lee Hart via EV ev@lists.evdl.org wrote: EVDL Administrator via EV wrote: Alas, any time you fix a declining EV battery by replacing the worst cells or blocks, rather than all of them, you have no way to know what other cells or blocks might turn toes up next week, next month, or next year. That's true. However, it is also true that the one cell that failed may have been infant mortality. It could have died young due to some quality defect or temporary abuse (like excessively discharging the pack, which killed the weakest cell). If you replace it, you can keep right on using the rest of the pack for an extended period. I've done what they describe with lead EV batteries, replacing blocks as they fail. With that situation it's mostly a losing game, because once a couple blocks die, the rest usually aren't far behind. This is often true because the driver and the battery charger don't *know* there's a problem. For example, if one cell shorts, the charger blindly charges the remaining pack to the full voltage that was needed with all cells good. That overcharges the remaining good cells, driving them into an early grave. Coincidentally, this is a NiMH question I'm facing too. I have a 36v 10ah NiMH e-bike battery here that's on its last legs. I've been debating whether to (a) replace just the bum cells and see how it goes, (b) replace all the cells, or (c) gut the battery and try lithium cells instead. If the original cells were high quality, they would all have been well matched. When one of them fails, the rest may not be far behind because they are all so much alike. For example, I've tested Prius nimh modules; even my 10-year-old ones are as alike as peas in a pod. If the pack is made from el-cheapo cells with negligible quality control, you could easily have a few lemons that died young, and are making the whole pack look bad. For example, I tested a set of ten 12v 7ah batteries from an anonymous Chinese manufacturer in a UPS; 4 were junk, and the remaining 6 varied from 1.7ah to 4.2ah. I was able to replace the 5 worst, and keep using the remaining 5. The only way to know for sure is to TEST. Test each cell or battery, and see what you've got. If they are all low in capacity, then it's time to replace the pack. If only one or two are significantly worse than the rest, replace them and keep going. :-) -- Obsolete (Ob-so-LETE). Adjective. 1. Something that is simple, reliable, straightforward, readily available, easy to use, and affordable. 2. Not what the salesman wants you to buy. -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/fb959645/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
Here is one test unit available for Prius packs: http://www.go2hev.com/hybrid-vehicle-battery-testing-and-analysis-kit.html The maker Automotive Research Design (what an instructive name) does more than just produce this test unit - they do a lot of training of mechanics by various means. http://www.go2hev.com/home.html OEM cell test equipment seems to come from ARBIN http://www.arbin.com/ On Mon, Nov 17, 2014 at 2:29 PM, Michael Ross michael.e.r...@gmail.com wrote: Lee said: The only way to know for sure is to TEST. Test each cell or battery, and see what you've got. If they are all low in capacity, then it's time to replace the pack. If only one or two are significantly worse than the rest, replace them and keep going. :-) This was my assumption. I will be interested to see if the school or Hybrid Shop goes to this much trouble. If we were to estimate the labor required to test a Prius pack - what would that look like? Would it be any where near sat $1000? I would like to take a critical eye into these visits, but I have never looked close or far at a Prius pack. mike On Mon, Nov 17, 2014 at 1:33 PM, Lee Hart via EV ev@lists.evdl.org wrote: EVDL Administrator via EV wrote: Alas, any time you fix a declining EV battery by replacing the worst cells or blocks, rather than all of them, you have no way to know what other cells or blocks might turn toes up next week, next month, or next year. That's true. However, it is also true that the one cell that failed may have been infant mortality. It could have died young due to some quality defect or temporary abuse (like excessively discharging the pack, which killed the weakest cell). If you replace it, you can keep right on using the rest of the pack for an extended period. I've done what they describe with lead EV batteries, replacing blocks as they fail. With that situation it's mostly a losing game, because once a couple blocks die, the rest usually aren't far behind. This is often true because the driver and the battery charger don't *know* there's a problem. For example, if one cell shorts, the charger blindly charges the remaining pack to the full voltage that was needed with all cells good. That overcharges the remaining good cells, driving them into an early grave. Coincidentally, this is a NiMH question I'm facing too. I have a 36v 10ah NiMH e-bike battery here that's on its last legs. I've been debating whether to (a) replace just the bum cells and see how it goes, (b) replace all the cells, or (c) gut the battery and try lithium cells instead. If the original cells were high quality, they would all have been well matched. When one of them fails, the rest may not be far behind because they are all so much alike. For example, I've tested Prius nimh modules; even my 10-year-old ones are as alike as peas in a pod. If the pack is made from el-cheapo cells with negligible quality control, you could easily have a few lemons that died young, and are making the whole pack look bad. For example, I tested a set of ten 12v 7ah batteries from an anonymous Chinese manufacturer in a UPS; 4 were junk, and the remaining 6 varied from 1.7ah to 4.2ah. I was able to replace the 5 worst, and keep using the remaining 5. The only way to know for sure is to TEST. Test each cell or battery, and see what you've got. If they are all low in capacity, then it's time to replace the pack. If only one or two are significantly worse than the rest, replace them and keep going. :-) -- Obsolete (Ob-so-LETE). Adjective. 1. Something that is simple, reliable, straightforward, readily available, easy to use, and affordable. 2. Not what the salesman wants you to buy. -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good
Re: [EVDL] Hybrid battery reconditioning
On 17 Nov 2014 at 8:37, paul dove via EV wrote: You all need to read the link I posted. It explains how to recondition Nickle based batteries. It also explains the failure mechanism and why this works. I did read that page. It may be accurate - I'm not an electrochemist - but it reminds me of the woo-woo that lead battery pulse charging advocates use to explain why their chargers (like all other chargers!) temporarily improve battery capacity. That said, though I don't know about the physics of it, Saft for one does recommend re-conditioning their large flooded cells when they have declined in capacity. Note that I hyphenated re-conditioning. Large NiCd cells and monoblocks, as used in some EVs, aircraft, and locomotives, are normally shipped uncharged. When they're installed, they require a procedure callled a commissioning or conditioning charge. (For the small cells you get in and for portable gadgets, this is done at the factory.) For this, Saft specifies a 14 hour 0.1C constant current charge. If you do the math, you see that this is essentially a 40% overcharge. (FWIW, Saft recommends a 20% overcharge on every normal charging cycle. This is for their non-recombinant open cells, not the MR blocks.) Re-conditioning is (duh) just repeating this conditioning process. Again going from Saft's instructions, the block or battery is discharged at a controlled low rate (Saft says 0.2C) to below 1.0 volts per cell ( 5v for a 6v nominal monoblock). Once flat, the battery is given a fresh conditioning charge. Saft says that for re-conditioning you can use 0.2C for 7 hours, instead of 0.1C for 14 hours, if you're short on time. One thing I should point out. Re-conditioning as the term is used in NiCd (and possibly NiMH) battery maintenance is not what many car folks think of as reconditioning. That is, what these guys are doing to a NiMH battery for $1000+ is not really similar to having a shop rebuild your ICEV's alternator. That rebuilt alternator will probably run about as long as a new one would, but your re-conditioned NiCd or NiMH battery almost certainly won't work as well or as long as a new one. The Hybrid Shop say that they replace under-performing blocks. I wonder whether they use new or used modules for replacements. I also wonder how well re-conditioning works with sealed cells, as opposed to open (flooded) ones. I own a Maha NiMH AA-cell charger that claims to do a re-conditioning cycle. I admit I haven't used that cycle frequently, but I have yet to see it significantly improve any of my older NiMH cells' capacity. Another little wrinkle here. IIRC, Toyota's onboard software carries out a form of re-conditioning and/or equalization automatically on their hybrid batteries when the computer senses a loss of capacity. I haven't heard that this kind of mini-re-conditioning is done automatically on the (small number of) true Toyota EVs such as the RAV4-EVs. Maybe someone else knows. As to whether Ford's software does such a quickie tweak, I don't know that either, but you might want to find out. If I'm not mistaken, for their early Escape hybrid, Ford bought the design (and possibly the hardware) from Toyota. It was the design that Toyota had used in the first generation Prius, not the second generation. Hope this helps. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
I believe the RAV4 uses a Tesla made pack - Li ion I presume. On Mon, Nov 17, 2014 at 3:02 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: On 17 Nov 2014 at 8:37, paul dove via EV wrote: You all need to read the link I posted. It explains how to recondition Nickle based batteries. It also explains the failure mechanism and why this works. I did read that page. It may be accurate - I'm not an electrochemist - but it reminds me of the woo-woo that lead battery pulse charging advocates use to explain why their chargers (like all other chargers!) temporarily improve battery capacity. That said, though I don't know about the physics of it, Saft for one does recommend re-conditioning their large flooded cells when they have declined in capacity. Note that I hyphenated re-conditioning. Large NiCd cells and monoblocks, as used in some EVs, aircraft, and locomotives, are normally shipped uncharged. When they're installed, they require a procedure callled a commissioning or conditioning charge. (For the small cells you get in and for portable gadgets, this is done at the factory.) For this, Saft specifies a 14 hour 0.1C constant current charge. If you do the math, you see that this is essentially a 40% overcharge. (FWIW, Saft recommends a 20% overcharge on every normal charging cycle. This is for their non-recombinant open cells, not the MR blocks.) Re-conditioning is (duh) just repeating this conditioning process. Again going from Saft's instructions, the block or battery is discharged at a controlled low rate (Saft says 0.2C) to below 1.0 volts per cell ( 5v for a 6v nominal monoblock). Once flat, the battery is given a fresh conditioning charge. Saft says that for re-conditioning you can use 0.2C for 7 hours, instead of 0.1C for 14 hours, if you're short on time. One thing I should point out. Re-conditioning as the term is used in NiCd (and possibly NiMH) battery maintenance is not what many car folks think of as reconditioning. That is, what these guys are doing to a NiMH battery for $1000+ is not really similar to having a shop rebuild your ICEV's alternator. That rebuilt alternator will probably run about as long as a new one would, but your re-conditioned NiCd or NiMH battery almost certainly won't work as well or as long as a new one. The Hybrid Shop say that they replace under-performing blocks. I wonder whether they use new or used modules for replacements. I also wonder how well re-conditioning works with sealed cells, as opposed to open (flooded) ones. I own a Maha NiMH AA-cell charger that claims to do a re-conditioning cycle. I admit I haven't used that cycle frequently, but I have yet to see it significantly improve any of my older NiMH cells' capacity. Another little wrinkle here. IIRC, Toyota's onboard software carries out a form of re-conditioning and/or equalization automatically on their hybrid batteries when the computer senses a loss of capacity. I haven't heard that this kind of mini-re-conditioning is done automatically on the (small number of) true Toyota EVs such as the RAV4-EVs. Maybe someone else knows. As to whether Ford's software does such a quickie tweak, I don't know that either, but you might want to find out. If I'm not mistaken, for their early Escape hybrid, Ford bought the design (and possibly the hardware) from Toyota. It was the design that Toyota had used in the first generation Prius, not the second generation. Hope this helps. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL:
Re: [EVDL] Hybrid battery reconditioning
What I really want to guess is - do we think they can actually do a good job of reconditioning a Pius pack for $1500? What if there were some problems with the pack? I am not trying to learn how to do it in a home situation (maybe later), this is about - is it likely the ARD system actually does good work? You can see my problem - I don't know what good work would look like for a Prius Pack. Supposing a pack that is needing a lot of work. Then you have testing, probably some tear down and RR of cells. I don't know what is in a Prius pack - is there a charger? BMS? All that is handled by the car's electrical system? Do we know how much Prius NiMH cells cost? Used ones? New? A whole new pack? On Mon, Nov 17, 2014 at 3:28 PM, Lee Hart via EV ev@lists.evdl.org wrote: Michael Ross wrote: Here is one test unit available for Prius packs: http://www.go2hev.com/hybrid-vehicle-battery-testing-and- analysis-kit.html The maker Automotive Research Design (what an instructive name) does more than just produce this test unit - they do a lot of training of mechanics by various means. http://www.go2hev.com/home.html OEM cell test equipment seems to come from ARBIN http://www.arbin.com/ If you got the dough, then it's a go. But this tends to be expensive commercial equipment and training for professionals that will do this for a living. Lee said: The only way to know for sure is to TEST. Test each cell or battery, and see what you've got. This was my assumption. I will be interested to see if the school or Hybrid Shop goes to this much trouble. Yes, this is a concern. I notice that the go2hev.com unit says it spends 20 *seconds* doing the power test, and the graphs say the amphour test is similarly brief. Now if you're in a shop and working by the hour, you want the quickest possible test, regardless of its accuracy. But I have to wonder how accurate the data that you get from such a short test will be. If we were to estimate the labor required to test a Prius pack - what would that look like? Would it be any where near sat $1000? A typical auto repair shop is likely to charge $100/hour. At that rate, $1000 is about 10 hours of work. They have to pay for all that equipment and testing, right? It can obviously be done far cheaper yourself, if you're willing to invest your time and a few dollars for simple equipment. A voltmeter, some light bulbs for a load, a commercial battery charger, a clock, and a clipboard are sufficient for basic testing. That's what I used to do. I learned a *lot* about batteries this way! Or, you can buy a simple battery tester/cycler, intended for the R/C model cars and planes. For example, I have a Model Rectifier Corp. Super Brain 989. It tests lead-acid, nicad, nimh, or lithium cells or batteries up to about 24v and 20ah capacity. Cheap (and cheaply made), but it works adequately for hobby use. There are many similar units. Or, you can build my Battery Balancer (or something like it -- the plans are open source and on the web). It does what any battery tester has to do: Select a battery or module, charge it under known conditions, discharge it under known conditions, compare and record the results. I've been building and refining it for over 15 years! It's at http://www.sunrise-ev.com/ balancer.htm -- Don't worry about people stealing your ideas. If your ideas are any good, you'll have to ram them down people's throats. -- Howard Aiken -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/a9e7b232/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
The original 1999-2000 Rav4-EV used 95Ah NiMH blocks and these vehicles are still going strong... Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Michael Ross via EV Sent: Monday, November 17, 2014 12:15 PM To: EVDL Administrator; Electric Vehicle Discussion List Subject: Re: [EVDL] Hybrid battery reconditioning I believe the RAV4 uses a Tesla made pack - Li ion I presume. On Mon, Nov 17, 2014 at 3:02 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: On 17 Nov 2014 at 8:37, paul dove via EV wrote: You all need to read the link I posted. It explains how to recondition Nickle based batteries. It also explains the failure mechanism and why this works. I did read that page. It may be accurate - I'm not an electrochemist - but it reminds me of the woo-woo that lead battery pulse charging advocates use to explain why their chargers (like all other chargers!) temporarily improve battery capacity. That said, though I don't know about the physics of it, Saft for one does recommend re-conditioning their large flooded cells when they have declined in capacity. Note that I hyphenated re-conditioning. Large NiCd cells and monoblocks, as used in some EVs, aircraft, and locomotives, are normally shipped uncharged. When they're installed, they require a procedure callled a commissioning or conditioning charge. (For the small cells you get in and for portable gadgets, this is done at the factory.) For this, Saft specifies a 14 hour 0.1C constant current charge. If you do the math, you see that this is essentially a 40% overcharge. (FWIW, Saft recommends a 20% overcharge on every normal charging cycle. This is for their non-recombinant open cells, not the MR blocks.) Re-conditioning is (duh) just repeating this conditioning process. Again going from Saft's instructions, the block or battery is discharged at a controlled low rate (Saft says 0.2C) to below 1.0 volts per cell ( 5v for a 6v nominal monoblock). Once flat, the battery is given a fresh conditioning charge. Saft says that for re-conditioning you can use 0.2C for 7 hours, instead of 0.1C for 14 hours, if you're short on time. One thing I should point out. Re-conditioning as the term is used in NiCd (and possibly NiMH) battery maintenance is not what many car folks think of as reconditioning. That is, what these guys are doing to a NiMH battery for $1000+ is not really similar to having a shop rebuild your ICEV's alternator. That rebuilt alternator will probably run about as long as a new one would, but your re-conditioned NiCd or NiMH battery almost certainly won't work as well or as long as a new one. The Hybrid Shop say that they replace under-performing blocks. I wonder whether they use new or used modules for replacements. I also wonder how well re-conditioning works with sealed cells, as opposed to open (flooded) ones. I own a Maha NiMH AA-cell charger that claims to do a re-conditioning cycle. I admit I haven't used that cycle frequently, but I have yet to see it significantly improve any of my older NiMH cells' capacity. Another little wrinkle here. IIRC, Toyota's onboard software carries out a form of re-conditioning and/or equalization automatically on their hybrid batteries when the computer senses a loss of capacity. I haven't heard that this kind of mini-re-conditioning is done automatically on the (small number of) true Toyota EVs such as the RAV4-EVs. Maybe someone else knows. As to whether Ford's software does such a quickie tweak, I don't know that either, but you might want to find out. If I'm not mistaken, for their early Escape hybrid, Ford bought the design (and possibly the hardware) from Toyota. It was the design that Toyota had used in the first generation Prius, not the second generation. Hope this helps. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver
Re: [EVDL] Hybrid battery reconditioning
Indeed - EV converters that chose to use NiCd (especially the flooded variant such as the ubiquitous Saft BB-600) found that capacity will decline relatively rapidly while keeping the charge within 100-0% so regularly they needed to completely discharge the pack (start with driving it for their longest trip and then continue discharging, for example with the heater) Then they needed to charge 140% capacity which essentially restored all previous lost capacity. Prius senses balance within its pack (it monitors every second connection between the 7.2V modules) and if they are out of balance, it will first attempt a looong slow overcharge. You will notice this while driving that the engine will not shut of for several hours (can be split over several trips) so the car can do that 140% commissioning charge (it never discharges since the pack is needed to start the car and you cannot predict when the owner will turn it off). Once that is attempted (probably more than once) and still unbalance is found in subsequent normal use, the Prius will throw an error and request service because its pack is on the way out (or a module is bad). Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of EVDL Administrator via EV Sent: Monday, November 17, 2014 12:03 PM To: Electric Vehicle Discussion List Subject: Re: [EVDL] Hybrid battery reconditioning On 17 Nov 2014 at 8:37, paul dove via EV wrote: You all need to read the link I posted. It explains how to recondition Nickle based batteries. It also explains the failure mechanism and why this works. I did read that page. It may be accurate - I'm not an electrochemist - but it reminds me of the woo-woo that lead battery pulse charging advocates use to explain why their chargers (like all other chargers!) temporarily improve battery capacity. That said, though I don't know about the physics of it, Saft for one does recommend re-conditioning their large flooded cells when they have declined in capacity. Note that I hyphenated re-conditioning. Large NiCd cells and monoblocks, as used in some EVs, aircraft, and locomotives, are normally shipped uncharged. When they're installed, they require a procedure callled a commissioning or conditioning charge. (For the small cells you get in and for portable gadgets, this is done at the factory.) For this, Saft specifies a 14 hour 0.1C constant current charge. If you do the math, you see that this is essentially a 40% overcharge. (FWIW, Saft recommends a 20% overcharge on every normal charging cycle. This is for their non-recombinant open cells, not the MR blocks.) Re-conditioning is (duh) just repeating this conditioning process. Again going from Saft's instructions, the block or battery is discharged at a controlled low rate (Saft says 0.2C) to below 1.0 volts per cell ( 5v for a 6v nominal monoblock). Once flat, the battery is given a fresh conditioning charge. Saft says that for re-conditioning you can use 0.2C for 7 hours, instead of 0.1C for 14 hours, if you're short on time. One thing I should point out. Re-conditioning as the term is used in NiCd (and possibly NiMH) battery maintenance is not what many car folks think of as reconditioning. That is, what these guys are doing to a NiMH battery for $1000+ is not really similar to having a shop rebuild your ICEV's alternator. That rebuilt alternator will probably run about as long as a new one would, but your re-conditioned NiCd or NiMH battery almost certainly won't work as well or as long as a new one. The Hybrid Shop say that they replace under-performing blocks. I wonder whether they use new or used modules for replacements. I also wonder how well re-conditioning works with sealed cells, as opposed to open (flooded) ones. I own a Maha NiMH AA-cell charger that claims to do a re-conditioning cycle. I admit I haven't used that cycle frequently, but I have yet to see it significantly improve any of my older NiMH cells' capacity. Another little wrinkle here. IIRC, Toyota's onboard software carries out a form of re-conditioning and/or equalization automatically on their hybrid batteries when the computer senses a loss of capacity. I haven't heard that this kind of mini-re-conditioning is done automatically on the (small number of) true Toyota EVs such as the RAV4-EVs. Maybe someone else knows. As to whether Ford's software does such a quickie tweak, I don't know that either, but you might want to find out. If I'm not mistaken, for their early Escape hybrid, Ford bought the design (and possibly the hardware) from Toyota. It was the design that Toyota had used in the first generation Prius, not the second generation. Hope this helps. David Roden - Akron, Ohio, USA EVDL Administrator
Re: [EVDL] Hybrid battery reconditioning
On Nov 17, 2014, at 1:28 PM, Lee Hart via EV ev@lists.evdl.org wrote: Or, you can build my Battery Balancer (or something like it -- the plans are open source and on the web). It does what any battery tester has to do: Select a battery or module, charge it under known conditions, discharge it under known conditions, compare and record the results. I've been building and refining it for over 15 years! It's at http://www.sunrise-ev.com/balancer.htm I might be a bit confused by the terminology you're using. Is that not a BMS, a Battery Management System? Seems to me like it might be rather more sophisticated than many of the ones I've looked at, but it looks like they're both doing the same thing. ...and, if so, yours is definitely on the short list for consideration when I get to that stage of the project b ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Hybrid battery reconditioning
Ben, There are probably no definitive limits to either battery balancer or BMS. To me a BMS also manages charge and discharge cut off, as well as balancing. I suppose it could also have a built in charger, but that is not what I think when someone says, that there BMS. There are notification and warning functions, value readouts, etc. that could also be in a system. A battery balancer that does none of these other things is still a battery balancer to me, but wouldn't be a BMS. There should probably be a cell balancer, and BMS. But we call a series of batteries a battery just to be imprecise. On Mon, Nov 17, 2014 at 4:57 PM, Ben Goren via EV ev@lists.evdl.org wrote: On Nov 17, 2014, at 1:28 PM, Lee Hart via EV ev@lists.evdl.org wrote: Or, you can build my Battery Balancer (or something like it -- the plans are open source and on the web). It does what any battery tester has to do: Select a battery or module, charge it under known conditions, discharge it under known conditions, compare and record the results. I've been building and refining it for over 15 years! It's at http://www.sunrise-ev.com/balancer.htm I might be a bit confused by the terminology you're using. Is that not a BMS, a Battery Management System? Seems to me like it might be rather more sophisticated than many of the ones I've looked at, but it looks like they're both doing the same thing. ...and, if so, yours is definitely on the short list for consideration when I get to that stage of the project b ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141117/e2e2999c/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
