Monster UPS

[Bad Wolf]

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.


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BTW a friend took the other 120 batteries and hooked them up to his solar panels at his cabin in Vermont.

 

[Jags]

Holy catfish - thatsalotta batteries.

 

[JP11]

Man.. and i thought I was doing good with my little repurposed 1200watt PC UPS.

BUT! I only need about 7 seconds till the 15kw Kohler kicks in.

JP

 

[tom in maine]

You should be using some PV's and running your house on this. That is a lot of capacity!
Great score!

I have a friend who is in the recycling business. When Maine Yankee Nuclear Power Plant closed years ago, he got their backup batteries for the cost of removing them. As I recall, they were 2400 ah, 2volt batteries wet cell lead acid batteries. They were huge and he sold them to people with PV systems.
They are a lifetime battery. Not only because no one in their right mind would want to move them again.

 

[heaterman]

Might be a good thing to think about ventilation for that area if you haven't yet. Hydrogen gas is a byproduct of cycling batteries through charge/discharge cycles. Goes boom in a big way if it accumulates.

 

[BoilerMan]

Might be a good thing to think about ventilation for that area if you haven't yet. Hydrogen gas is a byproduct of cycling batteries through charge/discharge cycles. Goes boom in a big way if it accumulates.

This is actually code for stationary battery storage/charging in Maine at least. Although I've never seen a problem with people who don't. I thnk hydrogen disipates quickly and doesn't pool on the floor as other flammable gasses do. I'd still build a vented enclosure though, as hydrogen is the most explosive gas known to man!

TS

 

[Bad Wolf]

These are sealed batteries that "produce no emissions during normal operation" (from service book) The LEL for hydrogen is 4%, and they further say "normal air circulation in a ventilated facility will preclude any hydrogen build up" .

That said, I will make sure that I have good air flow during charging.

 

[heaterman]

It is indeed lighter than air so it rises to the top of the room the batteries are kept in. I remember looking at the set up for a 30KW solar setup and they had the batteries in a sealed cabinet that had small ventilation fans both in and out. Seems like they were controlled by a sensor of some type. It was a professionally installed packaged system and I'm sure it was standard equipment rather than an add-on component.

 

[mustash29]

Howdy "neighbor" SE CT here.

Very nice score on the battery bank. Reminds me of what we have at my work just in case the doo-doo hits the fan.

 

[Karl_northwind]

your "hanging up" for a long time is the absorbsion time for the charge. the charger will fill them up to a specific voltage, and then hold them there for a while to let the chemistry settle down, and then continue to bulk charge them up towards 100%. if you don't give them time to settle down a bit, you get more electrolysis and more hydrogen and need to add more water more often.

karl