Battery Vehicle Society

I'm currently running evaluations on a number of lead acid batteries for an EV project. I've been testing Trojan T-105s, Trojan T-125s and US2200 batteries, all of which have provided us with some good results in tests.

The vehicle runs at 72 volts, with a peak power drain of 125 amps and a typical drain of between 50-80 amps.

I would also like to trial some gel or sealed lead acid batteries as well. Has anyone got any good reports or recommendations on batteries they've used in EVs?

Quite a few folks seem too find the optima yellow top to be quite good, never used them myself

ChrisB

I have been reasoably satisfied with Powersonic batteries. And they are not too expensive - around £100 for a 12v 100AH battery. I tried Optima Yellow tops and they didn't give a very long cycle life.

Have a look at http://www.secbattery.com. Their red top AGMs should be of interest to EV owners. I know forum member dillond666 has some and I used some of their front terminal gel cells in my volvo. They are the only battery manufacturer that actually publishes detailed discharge data for their cells so you can see the actual capacity for say 50, 80, 125 amps etc.

I would like to know if elecsol's new agm batteries last as well as claimed.
also C&D technologies deep cycle units are said to last for 600 cycles to 80% dod
and 1800 cycles to 50% dod.
I am very very interested in the results of your tests.
I am using Haze agm units in my city-el so far 1,840 miles and 16 months.

I presume its the same as http://www.secukbattery.co.uk/ who are the UK distributers if they are then I had a bit of a failure with them, wanted to buy 5x 12v blocks but never really got anywhere with them they were (dunno if they still are) supplying the green power race folk, got a great quote the other year from them at the green power finals stand but when I went to try and order them the price bizzarely went up by a considerable amount, then they wanted delivery on top, so as green power is based near me asked if they could put them on the next deliver down to them and share costs or something, but that never came to anything so gave up with the company it was like they werent interested in selling batteries

ChrisB

I wasn't aware of this site till now, I contacted them through the site I mentioned and found them very helpful. That was about 4 years ago though, maybe things have changed.

Just noticed this thread. I found Sec battery to be fine to deal with. I haven't broken my 160aH red tops yet! My controller is set to 450A max battery current.
I do confess to worrying about the prospect of battery death though. When I eventually do break them I'll be doing everything I can
to persuade my wife that Lithium is the best replacement

Derek

Ok, my batteries are beginning to fade a bit now. When I get home from my daily 25 mile round trip the battery is really weak. I have looked after the battery as best I can but after one year I think it might be time to consider replacement or begging my employer to let me charge at work.

Question for the lithium owners out there, would 100aH of lithium be enough to replace 160aH of agm? I reckon a 50 cell pack would be about £4900, any comments?

I'm a little worried at the moment

D

Derek, My Matiz has 144 x 40ah cells configured as 3P48S, so effectively a 48 cell 120ah pack. I've now got 1 year and 5k miles on them with no signs of degradation (my Volvo got 4,500 miles from its lead acid pack). The pack is actually older than this, manufacture date Nov 09, it took me longer than I expected to get the car on the road. I would think a 50 cell 100ah pack would be fine for a small car. For reference, my car weighs 1060kg as it now sits. I have come to the conclusion that for lithium prismatic cells you should aim for less than 1C average discharge (so less than 100amps for a 100ah pack) to get long life from the cells.

Try and get charging at your work, this will buy you some time. Ideally with lead acid you should always try and recharge them after a drive, lead doesn't like sitting partially discharged and the shallower depth of discharge should improve battery life. Lithium is perfectly happy to sit at a partially discharge state.