Inverter for Homemade Battery Backup

traderfjp · Post by **traderfjp** » Mon. Dec. 17, 2007 7:14 am

I did a search but couldn't find anything. I was interested in using a marine batter, an inverter and a trickle charger to setup a battery backup for my stoker. Can I simply wire the battery to my inverter but also keep a trickle charger going on the battery at all times to keep it fully charged?

Thanks

av8r · Post by **av8r** » Mon. Dec. 17, 2007 8:44 am

I wouldn't leave a battery on charge all the time, even if using a sophisticated computerized float charger (once a month for a few hours is plenty), but to answer your question, yes...you could do that.

traderfjp · Post by **traderfjp** » Mon. Dec. 17, 2007 11:45 am

Is there any device that I can buy to switch the power to battery if I'm not there?

Post by **coaledsweat** » Mon. Dec. 17, 2007 12:00 pm

An "automatic transfer switch", when your power drops out, it will energize the backup supply.

traderfjp · Post by **traderfjp** » Mon. Dec. 17, 2007 12:47 pm

Like this:
**Broken Link(s) Removed**

Yanche · Post by **Yanche** » Mon. Dec. 17, 2007 2:19 pm

Take a look at my old post about UPS back up system designs. See:

Post by Yanche - Flue Temperature Sensor Interlock Device

Designing something reliable is a challenge. The enamel insulation I'm referring to is the insulation on the motor windings. It's what fails from high voltage spikes. It's also why motors on variable frequency drives cost so much more. The winding insulation is so much better and more expensive.

traderfjp · Post by **traderfjp** » Mon. Dec. 17, 2007 4:32 pm

I read the whole thread and it kinda went off topic pretty quickly so I didn't really learn to much except that a computer UPC is not a good diea for the type of motors we have.

Matthaus · Post by **Matthaus** » Mon. Dec. 17, 2007 4:39 pm

If you can find a tru sine inverter with battery charger for decent price that works pretty well. Then just go to Sams and buy a couple deep cycle batteries and you are ready for the power to go out.

I have been buying too many things on ebay lately so I have to wait for a bit.

av8r · Post by **av8r** » Mon. Dec. 17, 2007 4:45 pm

Matthaus wrote:If you can find a tru sine inverter with battery charger for decent price that works pretty well. Then just go to Sams and buy a couple deep cycle batteries and you are ready for the power to go out.

I have been buying too many things on ebay lately so I have to wait for a bit.

Search for "pure sine" on ebay. Lots of them out there for cheap. 1200 watt for under $150

starise · Post by **starise** » Thu. May. 29, 2008 12:39 pm

As the owner of a stoker that uses wall power for the blower and feed mechanism I am also kicking this idea around. Although I do have a generator I wanted a solution that would give me very fast results in the event that its either (A) very late at night or (B) we are away from home when this happens.
This is a dated post however this problem will surely come up again sooner or later. Here is my solution and it might also be a good solution for you.
Purchase a DPDT (double pole double throw) relay with a 120 volt house voltage coil. Purchase a sealed battery safe for indoor use. Purchase a decent inverter.Purchase a trickle charger. I already have a small trickle type charger I yanked from a bad portable car jumpstarter. Anyone else doing this has a few options to avoid overcharging their storage battery. Option 1. Buy an inexpensive digital timer. I have one with a small LCD readout that plugs right into the wall and will carry the current from the small trickle charger,I think I paid 15 dollars for it.This is the kind of timer that plugs into the wall and has usually one female plug to add what your timing to.Set it up to charge whatever is recommended for your battery.
Option 2 is the X10 control system. Its cheap and uses your houses wiring for control. Because I had previously installed the X10 system to operate my pool pump,lights and alarms,I'll be using this. You can learn more about it at http://www.X10.com. With this system I have software on my laptop to set up timing schedules for any X10 module. So I'll set it up to only charge the battery periodically.
This is how it will basically operate- When the power is on the relay is energized and contacts are connected to the NO ( normally open position or closed when powered)and is feeding power to the stoker as usual. When there is a power interruption the relay is not energized and so the contacts to battery power that are connected to the NC terminals (were open but now closed because of power loss) . The power will now be switched to the inverter/battery system.
When power is restored the relay pulls back in and normal operation has returned without my ever needing to get out of bed. I have been told a reading stoker went for 8 hours on one of those car jumpstarters with a built in inverter. With a good battery I could take my good old time starting and hooking up the generator if the power is out for very long.
OK I should also state that if your not familiar with voltage/current and hooking up relays etc. better to get someone else to help out with this one that DOES know. I certainly don't want anyone hurt.Safety has to be first here.

japar · Post by **japar** » Thu. May. 29, 2008 9:34 pm

I had purchased a Tripp-Lite inverter charger that does everything. 2000 watts is 24 volts takes 2 12v batteries. When the power goes off it comes on automatic. Then recharges automatic.I guess if I lost electric for a long times I could just swap batteries with my diesel truck that also has 2 batteries. it was a ebay find. Funny thing I purchased it so the oil boiler would work and I would have heat incase of power outage. Now I have a coal stove and the boiler is usually off.

Highlander · Post by **Highlander** » Thu. May. 29, 2008 9:52 pm

I too have a TrippLIte unit, mine is a 500VA unit and I power it with a single size 29 marine battery. When the power went out, it kept the boiler and circulator running for 7 hours and still had some time left in the battery. I found it on Ebay for $50. There are others out there too, people use them in RV's and other mobil applications when they don't want to use a generator.

traderfjp · Post by **traderfjp** » Wed. Aug. 13, 2008 11:02 am

Your 50.00 find may be the deal of the century. The lowest price I could find was about 280.00 on Ebay.

sandman · Post by **sandman** » Wed. Aug. 13, 2008 11:43 am

if you use a fully auto battery charger, plug it in hook it up and your all set.
just check the water level in the batts every 4 month's or so.

if you do this with a ups, find the charging circuit and disconnect it. you don't want to have two batt chargers on at the same time and imho the ups one is too small to charge the big batts.

whatever you do don't get a cheap inverter, only get a sine wave inverter.

btw: I have a tripplite kinda like the one in the pic and while it's a good inverter it's not a sine wave inverter

a modified sine wave inverter will cause your motors to run hotter and make them burn out faster.

the only thing I don't mind running on a modified sine wave inverter are lights and a toaster.

figure out what your load is and get an inverter that is at least two times bigger than what you need 3-4 times bigger is even better.

traderfjp · Post by **traderfjp** » Wed. Aug. 13, 2008 11:59 am

A batter charger will not allow an instant transfer of power when the lights go out. I have the inverter and can buy a battery and charger but what happens when the sotve goes out in the AM?

Inverter for Homemade Battery Backup

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