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Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 12:42 pm
by sandman
the ups will automatically go to batt power via the inverter once you lose power

if you get a sign wave inverter/charger it will do the same thing.

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 3:53 pm
by PelletstoCoal
There is a complete unit for stove back-up...."stovesentry"...includes a charger, trans switch, and inverter....systems go 400-600 plus marine battery. Here is another thing to consider beaware that all inverters are not the same. Pure or True Sine Wave inverters and modified sine wave inverters differ by design and price. Pure sine wave is used for appliances that are controled via a computer and the dirty power of a modified sine inverter may contain too much noise to operate it properly. A modified sine wave inverter may run 79.00, but that same sized inverter in a prue sine wave may go for 199.00, big difference. I would siggest AGM (advanced gel matting) batteries, more charging cycles and can be mounted any position. By the way this stovesentry is marketed toward pellet stove owners, but power is power, it will work.
Frank

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 5:50 pm
by traderfjp
The Stovesentry is nice but pricey. I think I'l buy a high end UPS with a bad battery and then convert it with a car battery. I can mount it in the basement, under my stove, and run an extension cord. A perfect solution.

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 8:26 pm
by traderfjp
Sandman: How long can you run the typical stoker motor on a modified sin wave before it starts to over heat? What's your best estimate?

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 8:40 pm
by sandman
Sandman: How long can you run the typical stoker motor on a modified sin wave before it starts to over heat? What's your best estimate?
no idea, but if you going to get a surplus ups it wont matter I think there all sine wave inverters.

iv'e never measured the temp and only run sine wave inverters.

as a general rule I wont run motors off anything other than a sine wave inverter.

i have a off grid/solar camp.
sometimes I think the inverter supply's better power than what I get at home from the grid.

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 9:11 pm
by traderfjp
I was wondering if you knew if it's possible to wire two batteries in paralle for a inverter. I think you would have 24v instead of 12v but is that a problem?

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 9:33 pm
by Titus
These babies handle the charging, inverting, switching, etc.

http://www.tripplite.com/EN/products/product-seri ... =314&CID=1

Wiring 2 12v batteries leaves you with 12v. Wiring in series would give 24v.

2 batteries in parallel effectively gives you the equivalent of a bigger battery.

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 9:48 pm
by traderfjp
After I read your post that song "If I was a rich man" started playing in my head. Hey it's better to have songs in the head than voices. One means you're happy and the other means you need to windex your scope.

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 11:31 pm
by sandman
traderfjp wrote:I was wondering if you knew if it's possible to wire two batteries in paralle for a inverter. I think you would have 24v instead of 12v but is that a problem?
some of the ups's are 24v

you have to set up the batteries for whatever voltage your inverter is designed to be run on

if you need 24v use two 12v new batteries in series that are the same make, model and age.

same deal with any number of batteries in parallel.

or in cases like my camp where I have a 1800ah batt bank of 10 L16 batteries in a series parallel bank

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 11:50 pm
by traderfjp
Thanks. I won an APC 1000VA SmartUPS for about 80.00. They sell for 400 new. I'm thinking it must have a beffier design than the less expensive units. I can't wait to impliment the hack. Do u think the UPS can keep the battery charged or should I get a charger and test the battery every few months. I'll use the UPS and Battery for short outtages. I also have an inverter that I can hookup to my car for longer outtages.

Re: Inverter for Homemade Battery Backup

Posted: Wed. Aug. 13, 2008 11:54 pm
by sandman
i did the ups thing more than 10 years ago.

i disconnected the ups's batt charger. as I recal it was around 1a barely enough to keep the batteries topped off.

if it was me i'd disconnect the ups charger and get a fully auto charger and as many new deep cycle batts as you want to hook up to it

Re: Inverter for Homemade Battery Backup

Posted: Thu. Aug. 14, 2008 7:10 am
by jockel
I have been looking for a solution for power back up and this looks like a good choice. All the parts in one package except for the batteries.

I priced out all the different pieces that I thought were going to be needed and the cost is comparable. Plus I would not have to futz with it every month. We have a generator and wanted something that would be automatic to switch over if we were not home and would give us time to power up the generator in the middle of a stormy night if needed.

I will have to price shop to see if I can come up with the great price points others have mentioned. So far the vendor site is talking four or five hundred for the size I think I want. I need to be able to power our sump pumps as well as the stove if the power goes out.