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Discussion Starter #1
I have a chance to pic up these: http://www.mdsbattery.com/shop/productprofile.asp?ProductGroupID=1567

Not from that website but that model. I can get up to 300 of them for $5 each no shipping because they are local to me.

I am planning a 72 volt local roundabout with a 10 mile range. I'm thinking getting 36 of these in a series parallel configuration.

Do you think they would be up to the task?
 

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Anyone selling batteries for $5 each has a bunch of worn out batteries. That said... it aint a lot of money. If you can do a load test and pick some "better" ones out of the bunch....Perhaps ok for a "trial"... but u'll be looking for something better real soon..
 

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Discussion Starter #3
I forgot to mention the bats are 2 years old and are new in the box. We picked 4 bats at random and did a 100 amp load test and all bats tested fine. And the were charged at the factory 2 years ago.
 

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means they have still about a year of usefull service life left, looking at the average for lithium batts.. on the other hand, for a runabout with a short range, they should do fine the comming year (and maybe longer if you're lucky :) they won't flatout quit, they will just get progressively worse)
 

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most AGM's are sold at a discount after 8 to 12 months on the shelf. It is best if they are kept charged up ...even if they do loose a lot less than floodies (1 - 3%/ month), keeping them charged is best. Probably the most important question you could ask is at what temperature they were stored. (actually, this is even more important if they were in use......) If I remember correctly, life is halved for ever 10 degree C above 22. As mentioned, the capacity will have decreased somewhat, but from experience I would say you should have about 85% capacity if stored properly. It likely wont show up in voltage difference either. They will appear fully charged and discharge normally... you just wont get as much out of them. 10 years is a common life for AGM service life. Of course, how they are used/abused determines this ultimately.
 

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Discussion Starter #6
We just came home with 4 of them. They are all being charged up and tomorrow I will take out one of the 12v bats from the golf cart out and put 4 of these $5 bats in parallel. I just want to see how the compare to the $50 12v deep cycles we have in the cart.

The battery distributor also said that if I'm not interested in any of the bats that all 300 will be recycled. All of them in factory sealed boxes. What a waste.
 

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I would love to have a deal like that. I need batteries for a home solar system, and, batteries down here are a PREMIUM. Too bad you-they are so far away from Florida. I would gladly pay that and shipping for 10-15 of those batteries.
 

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Given your limited range requirement, IMHO you would be best served with a set of well abused deep cycle batteries. You might be able to get those at about $5 a piece too. I would be afraid of the amount of current required through those relatively small terminals. On the other hand, I sure would like to see this configuration attempted, because those are readily available batteries around here....
 

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Discussion Starter #9
Did some testing today. In the golf cart we had a $50 group27 deep cycle and on the other side 4 of these surplus batteries paralleled. Both 12v sources were then in series. We put a volt meter on each battery. The group 27 bat started at 13 volts. The surplus bats started at 12.7 volts. During initial acceleration the group27 dipped to 12.3 and the surplus bat down to 11.7 volts. After as little as 5 minutes the surplus batteries were almost always in the 11 volt range and the group27 above 12. At rest the surplus bats bounced back to 12.4 and the group27 12.8 volts.

My conclusion after this is that I would have to have an awful lot of these surplus bats to equal a cheap deep cycle. Compare the performance to weight to a Trojan battery and there is no question the Trojan would be the winner. The kicker is the price. The best application for these things I think would be for relatively low current applications. Using them in an EV, even at this price, I don't think the best.

Anybody disagree?
 
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