Quality of Different AGM batteries

[flashedarling]

I was thinking about going LiFePO4 but I've realized that I'm not as limited by weight on my motorcycle and can go with the cheaper AGM batteries. However I don't know which kind of 75ah AGM to get. Could anyone tell me anything about the quality of some of the following brands. For reference I'm building a 72v pack with either 65 or 75ah for a total weight of 300-350 pounds (about a 100 pounds heavier than the engine I'm removing from my bike)

First off I can get a good price on PowerStar batteries either from them or on eBay
http://www.powerstarsla.com/wheelchair_battery.html

Or I can go to batteryspec.com and get Tempest Brand brand batteries
http://www.batteryspec.com/cgi-bin/cart.cgi?action=link&product=80&sub2=800095

These both are touted as deep cycle batteries and are in my price range so I think they should work. However I don't know things like temperature ranges, how they handle constant output of up to 100A, or how many cycles they can take. I know that lots of people use Optima Yellow top but those are rather pricey and a bit heavier, so if these other wheelchair batteries would work that is what I'm going for.

 

[safe]

I personally don't have experience with what you are looking at, but I have bought and used SLA cells successfully and have found that the cheap cells deliver pretty much what you would expect from them if you've done your homework. You do know that the harder you use the batteries (higher "C" rates) the quicker the battery will wear out. Since in my application I've done everything possible to reduce the stress on my cells the result has been positive even though the batteries where cheap. Higher stresses mean the cheaper cells might not work as well.

Have you thought of using a CVT? (continuously variable transmission)

The advantage of that for SLA's is that you can get better power while using less amps... this will make your batteries last longer and perform better.

I'm "hooked" on gears as the way to improve the electric motor, though I know that most people avoid doing it. Low rpms and high amps are great for power, but it's not great as far as heat and efficiency. (not great for the battery either)

 

[Beagle123]

I bought cheap AGM batteries from batteriestogo.com. The brand name was "universal battery." They were toast in about 3 months. A more respected brand is B & B batteries. I'm using them now, and they haven't quit yet (2 months). They seem to be going strong. The top of the line is Hawker batteries, but they cost 4x normal price.

 

[D-Man]

Basically, you want to see a graph from the manufacture showing the number of cycles an sla can deliver. Some companies don't have em or don't want you to see them. So some of the ones I've found that show graphs are Powersonic, which are still cheap, and BB batteries which have several lines BP,EB, and EVP series but are not cheap anymore.

 

[Beagle123]

The B&B batteries I bought weren't bad. They cost about $45 for 20ah, 12v batteries compared to about $31 for cheap chinese batteries. I would reccomend the B&B's.

 

[D-Man]

Did you buy them recently? If so where? The cheap version doesn't come in a 12v-20ah.

BP 17ah - cheap
EB 20ah - not cheap

 

[Beagle123]

I bought the slightly more expensive version. Its 20ah, but it has the exact same size ass the 17ah. I think its a bit heavier. I bought it from aventrade: 626-286-0118. Then I picked them up at the B&B werehouse which is near my house. You can contact B&B and they'll tell you the location nearest to your house. If I remember correctly it cost ne $200+ for 4 batteries.

 

[tropmonky]

Whew, 60+lbs each??? wow....

 

[vanilla ice]

I'm down a few blocks away from B&B every week. I never stopped by cause I figured it was just a warehouse and they would probably direct me to a retailer. But maybe I'll check it out one time.

 

[rkosiorek]

i used a couple of the B&B EVP series batteries in my EV-Warrior for years. gave me the best bang for the buck of any battery i tried. lasted a long time and delivered power for a longer time per charge than the cheap brands i've tried.

i liked them so much i'm trying to find a set that will fit my wheelchair. they got to be better than the crap the wheelchair/ mobility guys rip us off for.

rick