Power inverter from garbage

[mozartsgokart]

Just wanted to let people know that if your looking to go off grid and need a good power inverted.  Look for businesses that are tossing their dead apc/ups or similar units out.  This week I have picked up 3 units that only had dead batteries.  Each unit is PURE SINE and 2250 watts.  Two run at 24 volt and the other at 48 volt.  I already had deep cycle batteries at home for my smaller inverted.  After some simple rewiring.  I just saved my self about $3000.  I could power about 60 amps @ 120 volts.  I have 4 deep cycles running now I plan on upgrading to 8.

[theBINKYhunter]

what type of business usually dump these? i'm always looking for free stuff.

[mozartsgokart]

I see them from schools / universities occasionally, usually someone has the inside scoop on they type of entity.  I see many places that go thru them.  Sure tech places.  But even the smaller UPS units people keep in their home office work too.  For the last 4 years ive used two small APC units that max out at 750 watts and are a modified sine wave.. not great but did manage to run the sump and pellet stove.

Most of these units will not power up unless the internal battery is providing some power.  So if the batteries are completely shot, the unit appears dead.  Apply some internal power and plug in the wall and the unit magically powers back to life!

When I get done reassembling my system ill upload some photos.

[theBINKYhunter]

I see them from schools / universities occasionally, usually someone has the inside scoop on they type of entity.  I see many places that go thru them.  Sure tech places.  But even the smaller UPS units people keep in their home office work too.  For the last 4 years ive used two small APC units that max out at 750 watts and are a modified sine wave.. not great but did manage to run the sump and pellet stove.

Most of these units will not power up unless the internal battery is providing some power.  So if the batteries are completely shot, the unit appears dead.  Apply some internal power and plug in the wall and the unit magically powers back to life!

When I get done reassembling my system ill upload some photos.

i was going to ask for some photos, that would be great.

[archer]

interesting idea. yes please post some photos.

[mozartsgokart]

Here is a picture of the first inverter / UPS.  I had originally bought this back in 2007.  I had it attached to the pellet stove.  One long brownout killed the internal batteries.  I wrote APCs customer support and they sent me a whole new unit.. never asking for the old one back.. So I took the batteries out of this unit and ran some cable to the batteries.  The new replacement unit they sent is upstairs attached to the pellet stove.



My battery bank was built with blemish batteries.  Our local battery shop gets a ton of batteries that are from scooters.  Most of the battery banks only have one bad battery.. They condition / charge the other and sell it as a blemish battery.  $35 dollars for one 55 amp hour battery, deep cycle SLA.  Five years later the batteries still work. Once a year I unhook the whole system and individually charge / desulf each battery.



I will upload more photos of the new units once reassembled. What you see here is what I started with a few years ago and still works to this day.

[theBINKYhunter]

ah, thanks. now i know what you are talking about... they had some of those at the hospital i used to work at that 'didn't work'... wish i would have known about this back then.

[Joel]

Yeah, that's a cool idea. I never thought about scavenging UPCs for their inverters. Didn't actually know UPC inverters came as big as 2000 watts, though in hindsight it makes sense.  +1!

[mozartsgokart]

Well most you find for home wont be that big, for years mine only went to 750 watts.  Ill get pictures of my bigger system on soon.  The smaller systems I wouldnt rely on to run forever but for power outages that last a day or so they have worked great.  With the smaller system you have to balance your load.  I wont have that issue with the bigger one.

[theBINKYhunter]

so you're using these as the inverter for your solar panels and running them do your battery bank?

[pokeshell]

your charging 3 batteries off that thing? I chuck the all the time. Hell, some customers pay me to take them! I used one for a trade in on a fishing trolling deep cycle battery, there was a $25 markup if you did not have a battery to turn in, I pulled a battery out of a dead apc750.

Can you explain a little deeper on how you are using this?

[mozartsgokart]

Currently there are no solar panels hooked up to this rig.  Also the picture shows only 3 batteries.. there are 4 there, the picture got cropped or isnt showing the 4th. 

Each battery is 12v.  I have it wired in series currently for 48 volts, connected to a Tripplite UPS (no pictuure yet).  I can connect wires from the 48v to tap off 24 volts as well.  I could tap off 12 volts from each battery too but that is alot of extra cables.

The apc unit shown in the picture runs at 24v.  The Tripplite UPS units act as the charger, the rig I have currently is only a battery back up, with no solar or other alternative power coming in.  When grid power goes down, this kicks in.

Here is a pdf of the system, hope this clears up any confusion and gives you some ideas what you can build with others trash.

http://homeonthefreerange.com/wp-content/uploads/2013/06/battery-diagram.pdf

[theBINKYhunter]

gotcha, so you're using grid power to charge the batteries and then running an inverter on the other side to power your stuff in case the grid goes down... am i right?

[mozartsgokart]

Bingo!

I have solar panels, but they are the flexible portable kind, so do not leave them out or wired up. I have 5 powerfilm flexable 120 watt solar panels, purchased on ebay, right before katrina, for about 80 bucks a piece.

The end goal of this setup is to eventually build a travel trailer and split the inverters and batteries.  Some for the house and some for the trailer.  But so far, minus the solar panels, ive paid about only 300 for the whole rig.  The majority of the cost was the first and only UPS device ive purchased, shown in the picture above. 

In theory..  i can power about 62 amps @ 120v when the grid goes down.. but the reality is i dont because the draw on the battery would be crazy.  I just like knowing that.. I could

[Adam Campbell]

That's hysterical. I found a stack of these at a thrift store cheap and said "Nah, I wouldn't buy one because it probably has a worn out battery."

Never knew there was a "hacked" use for these things!

[Adam Campbell]

Looked at the diagram (thanks) — yeah, this is an awesome idea. I could see this being applied to a "bugout bus" or taking an old camper to the next level and using the engine to charge it.

I even saw an old box-ambulance converted into a pretty bad a$$ camper on Craigslist for about $5,000 one day awhile back — and this would be a great way to improve on something like that.

[theBINKYhunter]

well, i just put adds up on freecycle and craigslist to see if i can nap any of these for free and start working on this. i love this idea. my dad is also an IT guy so i told him if he ever has any go bad at his office to let me know.

[theBINKYhunter]

mozart,

i picked up a few of these the other day and was told they need batteries. i'm going to look into that and get these back online. do you have the info for how to rewire these? FYI i'm a noob to this so i'd like to not blow myself up

thanks!