On 24 Jul 2016 at 13:21, Lee Hart via EV wrote: > These Deka 8G31 gels are very good EV batteries, but only if carefully > used. They are sealed, provide good range, and can last a long time -- > as long as premium flooded, and much than AGMs.
I've used six Deka 8G24 batteries in my Elec-Trak E15 tractor for almost 19 years. Yes, the same set -- almost. I use another 3 in my New Idea R36 riding mower. These batteries were already used when I got them in 1997. East Penn had donated them to an EV racing team, who quickly found that the batteries didn't have the power they needed. That makes them at least 20 years old! Darned if they're not still working, though their capacity is starting to fall now. One failed altogether a few years ago and I replaced it with another used one from the same batch. > > However, you need to understand that gels are *low* current batteries. > You cannot draw high currents, or charge them to high voltages! I don't recall what the nominal current is in an ET, but I'd guess it's no more than 30-40 amps. IIRC the controller is limited at 150 amps. You can also roughly halve that current since I use the batteries "buddy paired." I use a simple cycle-dropping charger for each parallel pair. It's limited to 14.3 volts. That's the highest voltage I recommend for Deka Dominators. East Penn actually recommends 14.2v. > You'd want to turn down your controller so your peak battery current > does not exceed about 100 amps ... That's about right. Actually they have so much internal resistance that you're hard pressed to get much more out of them anyway, as both the racers and I found. Also, they have rather low capacity for their size and weight. That's because they're severely acid-starved. That in turn is one of the secrets of their long life -- the weak electrolyte effectively enforces an 80% DOD cutoff. I suspect it also inhibits positive grid corrosion. 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 Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
