Chris (and others) have also used these cells in their US Electricar truck. The take away: do *not* use flooded NiCD cells in an aluminum battery box. The KOH will eat the alu - even when coated several times in advance. The NiCD work very well in cold weather if that is where you live...
Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: [email protected] Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of EVDL Administrator Sent: Tuesday, April 02, 2013 12:56 AM To: Electric Vehicle Discussion List Subject: Re: [EVDL] Have LOTS of Saft aircraft nicads On 1 Apr 2013 at 15:25, Danny Miller wrote: > I know that CO2 from the air reacts with the potassium hydroxide and > forms carbonate. If this happens, does this poison the plates for good, or > simply weaken the electrolyte? I'm not an expert on these matters, but from what I've read (in Home Power), I don't think it does any permanent damage. According to the HP guide I have, you're supposed to check the concentration of K2CO3 every year or so. You replace the electrolyte if it goes over 15%, or every 5 years just to be sure. I have the HP instructions for titrating the electrolyte to determine K2CO3 concentration if you're interested, or you can do it the easy way just change it now and every 5 years. To change the electrolyte, you will probably want to have something on hand to neutralize the KOH in the old stuff. I'm not sure, but you may need to make arrangements with some kind of hazardous waste disposal facility, since your waste electrolyte will contain lithium. Have the new electrolyte ready before you start; you're not supposed to let the cell sit empty more than 5 minutes. It's KOH and distilled water. It should have an SG of 1.190 and should be doped with about 12g of LiOH per liter. Remove the caps (if your cell or monoblock has them) and invert the cell/block over a plastic tub. The instructions I have don't mention using Roland's distilled water rinse. Refill with fresh electrolyte. Stationary cells normally get a 1/8" to 1/4" layer of mineral oil (Chevron #22 Utility Oil only) atop the electrolyte to protect is from CO2 in the air and thus carbonation, but I don't think that would work so well for mobile cells. AFAIK none of the Saft EV cells or modules has ever used oil. What you really need here is sage counsel from folks who used these specific cells. I thought there used to be a Yahoo group of BB600 users, but I can't find it now. There's also at least one person on the Elec-trak mailing list (Christopher Zach) using BB600 NiCds in his ET, though he seems pretty cavalier about caring for them. I don't know whether he's a member of this list. >From what he says, mostly he just hammers them with the Elec-trak's blunderbuss charger, and waters them every now and again. I think he's been running them a good 8-10 years and doesn't seem to have any problems, so they must be pretty durable. However, you should probably ask him about the particulars. You can subscribe to the ET mailing list here: http://cosmos.phy.tufts.edu/mailman/listinfo.cgi/elec-trak 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) _______________________________________________ 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)
