Qty ~200 New 12V 5AH batteries - How can I use them for solar?

[LATTC Student]

I am certain any solar battery design with these wouldn't be efficient and I should just buy 100AH 12V batteries. But, I have 199 of these (new) that I received for free. Tried to sell the lot of them for $1/ea on craigslist, no takers.

Would anyone envision utilizing these for solar applications? If not, I will probably take them down to the local Security/surveillance vendor and donate them. I am sure they use these all the time.

First challenge would be the wiring sizing to run between the batteries (couldn't figure out that calc)

Tried figuring this out:
If I Parallel 20 batteries @ 5Ah = 100Ah (12V). Then Series four of these strings together for 48V@100Ah=4800Wh (total 80 batteries). I could repeat this again with another 48V@100Ah = 4800Wh. That's 9.6KWh using 160 of the 5Ah batteries

The wire sizing requirements and cost might be too much for those small F2 connectors in any large configuration. Any ideas if these can be manipulated for Solar battery use? I would need a 48V battery charger as well; not sure what that cost would be. The life of these batteries, although new, might not be worth the additional costs.

Thanks in advance for any interest in this design.

 

[LATTC Student]

One other variable. I have most of these (internal series) batteries in new APC RBC140 trays. Each of those trays contain qty 8 @12V-5Ah batteries (96V). I have 10 of those trays. If the Voltage math worked out, could I series some of these together somehow? Who knows.

 

[ggunn]

I am certain any solar battery design with these wouldn't be efficient and I should just buy 100AH 12V batteries. But, I have 199 of these (new) that I received for free. Tried to sell the lot of them for $1/ea on craigslist, no takers.

Would anyone envision utilizing these for solar applications? If not, I will probably take them down to the local Security/surveillance vendor and donate them. I am sure they use these all the time.

First challenge would be the wiring sizing to run between the batteries (couldn't figure out that calc)

Tried figuring this out:
If I Parallel 20 batteries @ 5Ah = 100Ah (12V). Then Series four of these strings together for 48V@100Ah=4800Wh (total 80 batteries). I could repeat this again with another 48V@100Ah = 4800Wh. That's 9.6KWh using 160 of the 5Ah batteries

The wire sizing requirements and cost might be too much for those small F2 connectors in any large configuration. Any ideas if these can be manipulated for Solar battery use? I would need a 48V battery charger as well; not sure what that cost would be. The life of these batteries, although new, might not be worth the additional costs.

Thanks in advance for any interest in this design.

Most likely they would not be usable for solar backup or anything else for AC power. Wiring them would be a nightmare and keeping their state of charge balanced would be virtually impossible.

 

[pv_n00b]

Yeah, it's not a matter of whether you can use them, it's a matter of if it's worthwhile. As a science experiment, it might be fun to do. But that's not the kind of thing we do on this message board. There are many resources out there for folks who like to experiment with something like this. Have fun with it. Try not to burn down the house.

 

[jaggedben]

I agree with the others. As I see it, you are getting into product standard areas here. If you were designing a small stand-alone solar product, like a solar light or fan for manufacturer, putting one or two each of these batteries into such a product might be useful depending on the application. But I think you are asking if they can all be used together for residential energy storage, or something like that. In that case, you are kind of designing an ESS, which you should not be doing without engineering training and going through a listing process. I'm guessing you won't find products that are listed to use these batteries in the configuration you're suggesting, in which case you should not do it. Especially if they are lithium.

 

[ATSman]

I am certain any solar battery design with these wouldn't be efficient and I should just buy 100AH 12V batteries. But, I have 199 of these (new) that I received for free. Tried to sell the lot of them for $1/ea on craigslist, no takers.

Would anyone envision utilizing these for solar applications? If not, I will probably take them down to the local Security/surveillance vendor and donate them. I am sure they use these all the time.

First challenge would be the wiring sizing to run between the batteries (couldn't figure out that calc)

Tried figuring this out:
If I Parallel 20 batteries @ 5Ah = 100Ah (12V). Then Series four of these strings together for 48V@100Ah=4800Wh (total 80 batteries). I could repeat this again with another 48V@100Ah = 4800Wh. That's 9.6KWh using 160 of the 5Ah batteries

The wire sizing requirements and cost might be too much for those small F2 connectors in any large configuration. Any ideas if these can be manipulated for Solar battery use? I would need a 48V battery charger as well; not sure what that cost would be. The life of these batteries, although new, might not be worth the additional costs.

Thanks in advance for any interest in this design.

You might try selling them in smaller quantities on ebay. More work for you but it would open up a larger buyers market.

 

[LATTC Student]

Thanks all for your feedback! it was a thought anyway. I will just donate them to the local security vendor.