Our power is pretty reliable, but once in a while it can drop momentarily or longer in storms when the wind is blowing hard or a tree takes down the lines, or whatever.

When that happens, the corn stops trickling in, and my fire goes out. And if the power comes on while the stove is still hot, the auger will start feeding corn again and fill up the stove.

So, I'm thinking a battery backup would be great to have. I know that computers tolerate dirty power since they have their own power supply within, and so I believe the cheap UPS power supplies meant for computers produce pretty much a square wave output.

I have heard the control board in the stove is somewhat sensitive to bad power and I don't want to fry mine by using a cheap UPS.

Does anyone have recommendations for a unit to use with a St Croix SCF-050? Should I be looking for a 'pure sine wave' UPS? Are there another options?

Thanks - Dave

www.eventempinc.com/stcroix/downloads/di...ce_Manual-Pellet.pdf talks a little about battery back up on page 18

Thanks, Andrew. That seems to confirm what I was thinking. I have learned there are three different types of UPS systems: backup, line-interactive, and online.

The online systems are the most expensive - incoming power is rectified to DC and then converted back to AC. The advantage is instantaneous switch-over to battery power, and the ability to put out clean power even in the face of frequency variations in the incoming AC. The downsides are expense and lower efficiency. But since my one-cylinder listeroid diesel generator produces power whose frequency varies somewhat, I'm thinking of going this more expensive route.

I'm looking at a Tripp Lite SU750XL, which would cost in the range of $400 delivered.

If anyone has any other specific suggestions for backup power for this stove please chime in.

Thanks - Dave

Hi Woodnmetalguy. I have a St Croix Auburn and I purchased a used Xantrex XS400 pure sine inverter connected to a deep cycle battery to use as backup. I have a battery tender connected to the battery to keep it topped up at all times. This inverter was from a boat and automatically switches to battery when the AC power goes out. I've had to run on battery several times and had no issues.
What ever way you decide to go just make sure it is a pure sine system.

I purchased a xantrex powerpack 1500 from ebay for about $250.

www.amazon.com/Xantrex-802-1500-XPower-P...erpack/dp/B00005RHQQ

it has 3 deep cycle batteries totaling 60 amp hours. The unit also has a built in charger. I made a generator from a power washer and altenator because the battery will only run the stove for 30-60 minutes. Battery backups aren't the most effective for long use, my stove pulls too much power.

I've got an APC automatic transfer switch which provides shore power when available, and if it fails it's plugged into the battery pack for backup power.

Edit - the battery pack also has DC terminals on it. I've hooked my altenator up directly to them, since the altenator needs a battery to run. It'll charge from there while still providing AC power via the built in inverter.

Thanks for the replies, nuclearrepairman and allenelson! I have heard of the Xantrex brand as having a quality product. Looks like there are several options, and they seem to be all in the $400-$500 price range new. I maybe will do some watching of what shows up on ebay for a little while.

Thanks - Dave

You can pick up a KILL-A-WATT plug in meeter and check your usage and see just how many watts your really pulling. Inverters get a lot more expensive the higher wattage you get. Just a thought

Yes, thanks. Good thought. Since I had one, I put it on when I was shut down for my weekly cleaning. Looks like the combustion fan alone draws about 55 watts, the combusion and circulation fans together are about 270 watts, and when the auger kicks in things peak at about 315 watts. It's a little hard to tell since the meter seems to average readings over the last second or so, so it's not clear what the real peak is.

But I guess I don't see any reason to go smaller than the company's recommended 750VA unit, which seems to be 480-500 watts. I think it's good to have a bit of excess capacity rather than being a bit short.

Thanks - Dave

Here's what I did
www.butkus.org/ups/ups.htm

Hi:
I have been using an APC xs 900 UPS backup for my St. Croix Auburn for 5 years. Last spring I had to replace the battery. I bought the UPS at Staples or Office Max for about $150. This model is discontinued now, but a similar model is available for $130 online. It is a medium level backup UPS for computers.

It keeps the stove going during brief power blackouts. Not great for a long term disaster, but when the lights blink on and off, the stove keeps going.

I live out in the country, and brief power outages are fairly common. This fairly cheap UPS makes all the difference.

John Elberfeld JElberfeld@aol.com