On Sun, May 31, 2015 at 10:35 PM, EVDL Administrator via EV <[email protected]> wrote: > On 31 May 2015 at 22:48, Lee Hart via EV wrote: > >> In this case, the ComutaCar charger is *not* voltage regulated, nor >> current limited, nor is there any shut-off timer. It is nothing but a >> big transformer and rectifier. > > I had a 1980 C-car. Its charger was pretty crude, but it was a little more > than this.
Clearly this wouldn't be good for Li batteries. Possibly, along with the contactor controller Lee mentioned. > > As for the need for a BMS, we don't know anything about Gail's "adoptee," > but I would caution against assuming that he can (or wants to) invest > significant amounts of time in EV maintenance. We want this person to have > a good experience with his C-car. > That is why I recommend LiFePO4. Once it has been set up you can forget about it. With lead acid you have to check the electrolyte level frequently depending on number of charges. You also had to deal with corrosion. All of that is gone with a properly setup LiFePO4 pack. > "Bottom balancing" may work fine for careful hobbyists. (I was going to say > "careful hobbyists like us," but I know myself well enough to know that I'd > wreck the battery if I tried it.) The average person just wants to drive > the car, not babysit it. > Then you would like my setup. All my worry/checking over the past 4 years have added a data point to the "no BMS needed" crowd's claims. The charger shuts off consistently and the controller won't work below a set voltage. Since my charger will only charge for a maximum of about 9 hours I usually recharge when I reach a little over 50% DOD otherwise I have to power cycle the charger to get it to not time out. Not an issue but something I have to consider if I want a full charge at the end. -- David D. Nelson http://evalbum.com/1328 http://www.levforum.com _______________________________________________ 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)
