I have a cordless B&D that i changed out to use 24v 20ah thundersky batts a few seasons ago and shared the battery for a while on my recumbent for assist. It certainly won't do my new 2+ acres but was cheap with dead batteries off of craigslist and the lighter batteries made it tolerable to push in the hundred degree heat. All it took was remove the old battery, connect the new one and I lazily just popped it out to take to the workshop for charging instead of making it permanent since it was intended to be a dual use battery.
On Monday, April 28, 2014, Michael Ross <michael.e.r...@gmail.com> wrote: > I have another battery from these people that seems just fine (after taking > it apart to see inside) > > > http://www.aliexpress.com/store/product/24V-40AH-LiFePO4-Battery-Pack-Electric-Bicycle-electric-Scooter-bicycle-E-Bike-Lithium-Ion-Long-life/328001_771068114.html > > This one is 24V 40Ah LFP and weighs 9kg. $500 including shipping BMS and > charger. 3 to 7 day delivery and the met that. These that 18650 cells with > welded straps for conducting the juice. > > I think I will try to get a used 24V B&D instead of reworking my old bottom > of the line MTD. > > I think my wife would love to have an electric mower. She hates asking me > to start them for her. It would be nice not having all the oil checking > and filling, And as the current mower works - the rod knocking and > smoking. We have an acre of mostly flat yard - 40Ah would go a long ways > and the charge time is about 2 hours. > > > On Mon, Apr 28, 2014 at 3:25 PM, Peter Eckhoff <peckh...@nc.rr.com> wrote: > > > Hello Mike, > > > > I'll second what Cal is saying below. To get the nut off, you have to > > place a wrench on the nut and "impact" it until the nut loosens. I would > > **not** use a compressed air impactor tool. I use my fist. Be careful > > because everything is free wheeling. If you leave your knuckles in the > > path of the blade, your knuckles are going to get whacked. There is no > > other place to place another wrench unless you weld a nut to the top of > the > > motor shaft. > > > > Like Cal, I keep a set of several "small plastic blade insulators" on > hand > > which is how they are described in the User's Manual. The word > "insulator" > > may seem like a misnomer but it is to "insulate" the shock of hitting a > > rock from damaging the armature. > > > > I converted a corded B&D to cordless. It uses 9 - 5 amphr 12 volt LA > AGMs > > to power the mower. It is enough to do a 7K square foot lawn. What used > > to take me 1.5 hours to do when corded, now takes about 45 minutes. > > > > I use a 1.3 amphr AGM for the tripping a small contactor. This battery > > goes down faster than the pack. I would use about a 2 amphr battery for > > each hour the contactors are tripped. That should give you plenty of > > cushion. > > > > I wrote a two part article for the Electric Auto Association's Current > > Events magazine. I have the submittals in PDF format. The B&D motors are > > DC universal motors that operate at 120 volts. The corded version has a > > full rectifier bridge on a little heat sink. It was mainly a rewiring > job > > to bypass the rectifier. > > > > I think the AGMs are the wrong type of battery for this project. > Normally, > > when not cutting the lawn, the motor consumes about 4 amps. When cutting > > thick grass, the motor consumes about 8 amps. It can spike to 10 amps in > > real thick grass or when the mower clogs up in thick grass. > > > > I have been contemplating upgrading this mower to Lithium. A set of 40 - > > 3.2 volt 10 amphr would be about right for an hour's worth of cutting and > > still have some reserve. I saw an ad for Shorai 12Volt 12 Amphr > batteries > > for $117 each and they weigh about 1.7 pounds. My 5.0 amphr batteries > > weigh 3.5 pounds each for an added weight (starter + pack support + > > contactor) of 35 pounds onto a mower that weighs 47 pounds for a total of > > around 82 pounds. This is about the weight of an ICE push mower. Twelve > > Shorai batteries would be around 20 pounds. The mower would be lighter > and > > so would your wallet of $1400 plus shipping. > > > > I have thought about purchasing 4 - 100 amphr CALB batteries and then use > > a converter to step up the voltage to 120 volts. At an efficiency of > 85%, > > the amphrs to the motor would be about 8.5. I am not sure if a converter > > could handle that much amperage. I was going to do some more homework > > before asking the experts here. Four CALB batteries would be about 600 > > dollars and a converter would run in the lower several hundreds. The > > savings would be substantial but I am not sure if the electronics would > > handle the load. > > > > The other thought would be to run the 4 CALBs into an inverter and leave > > the rectifier bridge intact. The inefficiency of the inverter plus the > > inefficiency of the rectifier bridge would likely sap the pack of a lot > of > > useful energy. I think this would be a nonstarter. > > > > I know of someone using a self contained electric mower. You might want > > to shoot him an email at theadm *A*T* AOL. If you are in the RTP area, > we > > are both "local". > > > > Everyone else I see running an electric mower are running with a cord. > If > > you want me to, I will ask my neighbors their brand and opinions. > > > > > > On 4/28/2014 1:27 PM, Cal Frye wrote: > > > >> I'm on my second Black and Decker push mower, corded type. I have a > >> small lawn, so avoiding running over the cord is not a major problem. I > >> won't advise on motor or batteries, but I can say B&D has a plastic shim > >> in the stack of washers holding the blade to the motor shaft. Said shim > >> has raised edges which grip either side of the blade, and an op-- > 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 <javascript:;> > <michael.e.r...@gmail.com <javascript:;>> > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140428/eefac1eb/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) > > -------------- next part -------------- An HTML attachment was scrubbed... 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