UPS Batteries

[oldmil]

I have a line on several dozen 12v ups battery cells.  I believe they are 7.6 ah, 12v sla's.  Do any of you think they will be worth messing with for a small solar system (enough to run a 12v radio, small 12v fan, cell phone charger etc... a weekend or so a month)?  The cells are less than 1 yr old and were never used as back up power.

Thanks for your opinions.

Oldmil

[TDC]

That depends.....  your cost?  Are they free?

[oldmil]

They are free.  They will be sent to the recycler otherwise.

Oldmil

[dnix71]

Free? Of course. I used to have some UPS batteries that were not being used tagged onto my system. They finally went dry and I took them into work and gave them to a coworker who takes metal to a local recycler for gas money.

[Bruce S]

Oldmill;
Getting the batteries free is good  .
The other side of the coin is what you already have available, or free or low cost.
A simple Solar panel setup with a inexpensive charge controller will go a very long way to what you ask.
Rich H and I used some of the very same sized batteries in our trip to the Philippines way back in 2010. We used smallish sized panels he found 10watt @12V and 17watt @12V.
The trick is to know how much energy you will need to store so you do not drain (kill the batteries) below 50%.
Since it doesn't look like you'll do heavy usage, then the 10 - 17watt panels should workout nicely.
DO NOT purchase the ones places like Harbor Freight and CostCo sells they just aren't work the $$$ for the wattage and limited life they have versus the size as well.

It would be best to grab the Amps labeled off each of the devices, add them all up, then add 20% more , then make sure you have enough battery to cover the max.

Let us know how you intend the recharge the batteries too.

Hope this helps
Bruce S
   

[oldmil]

Thanks Bruce.

I already have a 60 watt Keocera panel with 2 6v golf cart batteries to run things in the cabin.  Unfortunately, they froze this winter with the -30 F temps we had.  The batteries are 4 yrs old so I guess maybe it was their time.  I keep them topped off with distilled water but maybe I put too much in.  I may try these small batteries if/when the big ones die.  As I said, the only thing they need to power is a radio (car stereo with one speaker), the pezio on the fridge and the occasional phone or laptop charger. 

If nothing else, I can use the small batteries to power the light in the sauna.  I can just bring them home and charge them each time.

Oldmil