Battery Backup Power for 2 Pellet Stoves

[adam6979]

So here we use 2 pellet stoves as the only heat source. It gets real cold up here and power outages are pretty common. Most times just up to a 5 minute interruption but it can go for hours in a bad storm. What I wanted was a real budget conscious battery backup solution. So here is what I built.

I bought a Server Rack Mount APC Smart UPS 1400. The one I got was MODEL 885-7522/2. These models are built to use as long as you can provide power. The cheaper ones have a limited duty cycle. This is a several hundred dollar APC - however I paid $50 on Ebay because they thought it did not work. They didnt know without batteries they wont work!

Now I am in the used car parts business so I have unlimited access to car batteries so that is what I wanted to use. I also have this in an unheated / very airy garage so fumes are not an issue - wouldnt want to have car batteries charging/discharging inside the house.

Anyway I have two car batteries connected to make the 24V the APC needs and it gives around 2 hours for the pellet stoves to run. (Plenty of time to shut them down in cool weather or long enough to drag out the generator in cold weather.) It has worked very well and I have only replaced one battery once at a cost of $0 for me. You will see inline fuses for protection.

Just thought I would pass this along as I refused to pay the $500 the dealer wanted for a backup that would last only about 10 minutes and wont work the igniter... this one will and has a 950W capacity... bigger ones are available but this works fine for my needs.

I cannot get this to allow me to post an image but here is a link to it: http://postimg.org/image/5n7gbwqqz/

 

[TimfromMA]

I use marine batteries and get 8 hours of runtime for 1 stove.

 

[Wilbur Feral]

OP has great idea, and have noted Tim's excellent setup in past. Do similar with four 110AH batteries wired to 48V for a different APC SmartUPS. Powers stoves, refrigerators, security system, FIOS ONT, router and switches, and one always on PC (low power draw) for over 12 hours without a sweat, as all are wires to dedicated circuits for this. Will go much longer but do not want to discharge batteries below 50%. Allows me to shut down generator overnight, saving fuel and cost. When on AC the SmartUPS provides very clean power, and no need to have power down loss on these items when switching to generator.

 

[F4jock]

Yup. It CAN be done and done safely and cheaply. All it takes is an intelligent an knowledgeable approach to the problem. Nice job all!

 

[adam6979]

I use marine batteries and get 8 hours of runtime for 1 stove.

May I ask how many batteries you have hooked up and which batteries you are using? I was concerned with hooking up to many and if there was ever a short... well hydrogen bombs came to mind. I know a forklift has a ton of batteries and I have never seen any of them explode... I have considered adding more batteries for extended times, and who wants to drag out the genny at night in a snow storm.

 

[TimfromMA]

My APC is a 24V system so I had to use 2 batteries.

The batteries themselves are 90aH lead acid batteries I got from a local marine supply store. I know these batteries aren't ideal for in house use but I've taken a few precautions such as putting them well away from the stove in another room and using a fuse to prevent damage in the event the APC has a catastrophic failure.

 

[mchasal]

Nice setup. I'm still kicking myself for not taking the rack mount server UPS that I saw in the scrap bin at work 10 years ago (long before I had a pellet stove).