I just can’t seem to pass up anything free. I somehow decided that my 2 deep discharge batteries weren’t enough backup for my furnace.
They were disposing of the UPS system at work which still had 4 years left on the nominal 10 year batteries. So I took 18 of them and the racking system and set them up downstairs next to the furnace. Each battery is 2 cells of 2 volts, so when you hook them up in series you get a 4 volt 300 Amp/hr battery. So the 18 batteries give me six 12 volt banks for a total of 1800 Amp/hr.
This coupled with a 600 watt pure sine inverter and relay setup from Xantrex and I should be able to go for a couple of days.
One thing I did noticed is when I went to charge them, the charger would hang up at 85% for hours. If I turn it off and back on, it jumps to 95%. Eventually it will show 100% and I get the green light.
Just for fun I plugged the furnace into it the other day and let it run for 40 hours. The only thing calling for heat was the hot tub, and I fired the boiler for about 8 hours to bring the storage up to 175 for DHW. According to the Kill-o-watt meter I used a little over 2000 watts and the voltage never dropped below 12.5.
There are front panels and a top that I attached after I hooked everything up. A nice neat and clean setup.
.![Monster UPS Monster UPS](https://www.hearth.com/talk/data/attachments/103/103941-a3f5d3cdb4d972b9101f93207534247a.jpg)
BTW a friend took the other 120 batteries and hooked them up to his solar panels at his cabin in Vermont.
They were disposing of the UPS system at work which still had 4 years left on the nominal 10 year batteries. So I took 18 of them and the racking system and set them up downstairs next to the furnace. Each battery is 2 cells of 2 volts, so when you hook them up in series you get a 4 volt 300 Amp/hr battery. So the 18 batteries give me six 12 volt banks for a total of 1800 Amp/hr.
This coupled with a 600 watt pure sine inverter and relay setup from Xantrex and I should be able to go for a couple of days.
One thing I did noticed is when I went to charge them, the charger would hang up at 85% for hours. If I turn it off and back on, it jumps to 95%. Eventually it will show 100% and I get the green light.
Just for fun I plugged the furnace into it the other day and let it run for 40 hours. The only thing calling for heat was the hot tub, and I fired the boiler for about 8 hours to bring the storage up to 175 for DHW. According to the Kill-o-watt meter I used a little over 2000 watts and the voltage never dropped below 12.5.
There are front panels and a top that I attached after I hooked everything up. A nice neat and clean setup.
.
![Monster UPS Monster UPS](https://www.hearth.com/talk/data/attachments/103/103941-a3f5d3cdb4d972b9101f93207534247a.jpg)
BTW a friend took the other 120 batteries and hooked them up to his solar panels at his cabin in Vermont.