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, "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/b3ab f72d/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)
