Two other ideas: Use a pool timer, set it to come on 15 mins each day and connect your normal chargers so the batteries get a trickle every day.
Or lend your car to someone you trust to use and charge regularly until you return. Make sure they want to use the car, it is the only way to guarantee they will be charging it regularly. Cor. On Tue, Apr 16, 2019, 2:44 PM Lee Hart via EV <ev@lists.evdl.org> wrote: > David Delman via EV wrote: > > Thanks for the ideas Jay. It really isn't practical for me to remove the > > batteries and rewire them in parallel. > > > > I was wondering if I could build a simple "trickle charger" for the > > entire pack. > > > > I envision an isolation transformer 120vac in and 120vac out. The output > > connected to a full wave bridge rectifier with perhaps an incandescent > > light bulb in series with the output to limit the current. > > > > This would supply ~169.68 vac peak or just over 13v per cell. Provided > > that the output of the transformer was really 120vac... > > > > The question is, if I start out with balanced batteries will they stay > > balanced while being trickle maintained in series...? > > > > Dave > > > > OnTue, 16 Apr 2019, Jay Summet wrote: > > > > If this is a one-time park long term storage type situation, perhaps you > > could remove the batteries (or at least, their terminals) and wire all > > 12 in parallel and then use a small float charger on the whole set at > once? > > > > > > Alternatively, what is the self discharge rate of AGM's vs the projected > > length of storage? If it's just for a few months, you could possibly > > just charge them up fully and then disconnect them and be ready to > > recharge when you return. > > > > > > Jay > > > > > > On 4/16/19 2:39 PM, David Delman via EV wrote: > > > > I am going to have to store my eLectric DeLorean at a facility away from > > home. > > > > > > The car has 13 Sears PM-1 lead acid AGM batteries. > > > > > > Presently I use 13 individual chargers, one for each battery to keep > > them charged and balanced. This won't be practical where I am going to > > store the car. > > > > > > What is the groups advice for keeping the batteries charged and balanced? > > Hi Dave, > > You definitely don't want a "trickle charger". This is the cheapest, > crappiest kind of charger. All it does it put a continuous current into > the batteries. This will slowly overcharge them to death! > > For lead-acid, you want a "float" charger for long-term maintenance. It > holds a constants *voltage*, and lets the current fall to almost zero > when the battery is fully charged. > > But a float charger isn't practical for a long string of cells (like > your 120v pack). The batteries certainly won't be balanced; so some will > get more voltage (and overcharge), while some will get less (and not > fully charge). > > Also, float charging is what you do if you may need the batteries to be > ready and fully charged any time. For example, an alarm system or UPS > power supply where you may need it fully charged at any time. > > If this is for short-term storage (a few months), just fully charge > them, and store the car as-is. AGMs can happily sit for many months > without charging. > > Just make sure that there are *no parasitic loads* that are always-on > and connected! A clock, alarm system, keyless remote, or even your > individual battery chargers may draw power from the batteries when the > car is off! If you aren't sure, then disconnect the batteries before > storage. > > If this is for long-term storage, then I'd recommend removing the > batteries. Either keep them in your garage and charge them occasionally; > or just sell them and buy replacements when the time comes. > > The usual problem is that the batteries were good when the EV got > stored, but they never get charged and the storage lasts longer than you > thought; and the batteries all die. > > -- > Fools ignore complexity. Pragmatists suffer it. The wise avoid it. > Geniuses remove it. -- Alan Perlis, "Epigrams on Programming" > -- > Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at 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/20190416/e3a61a58/attachment.html> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
