Using a car battery with an APC UPS

[Red Squirrel]

I have an old UPS exactly like this one:

The battery on it is bad. Got the UPS used, was basically being thrown out, or I could keep it, so figured why not. It lasted me a few months then started beeping non stop and the battery light flashes.

It's over 100 bucks to replace the battery so it's not really worth it when I can get a new UPS for that price, but at same time I kind of don't like throwing out something that will work fine with a replacement part.

Would it be safe to hook up a car battery to it? Any special type of car battery I should use? A car battery is cheaper and will probably provide more juice. I'm guessing a deep cycle batter is probably the best idea. I heard of people doing this before but with lot of modifications.

 

[mpilchfamily]

Here is a link to a podcast about upgrading a UPS like you want to do. Watch it and it will give you the pros and cons to upgrading a UPS like this and how to do it.
http://revision3.com/systm/hackedups

 

[Red Squirrel]

Actually it's funny I was just just watching that on youtube. They do mention about trickle charging vs on/off charging and how trickle charging can be bad and decrease the life of the battery due to overcharge. I was also reading up that most UPS chargers can't even charge a car battery properly - some may even burn out. Guess it really depends on the quality of the UPS itself and how it handles charging.

 

[Miramonti]

Here is a link to a podcast about upgrading a UPS like you want to do. Watch it and it will give you the pros and cons to upgrading a UPS like this and how to do it.
http://revision3.com/systm/hackedups

They don't even use Sealed Lead Acid batteries, what's up with that.

I%

 

[Red Squirrel]

They don't even use Sealed Lead Acid batteries, what's up with that.

I use Optima SLA marine batteries from Costco. They cost about $80 each, and have them attached to an apc 600 and apc 750.

They work great, with exception of the annoying intermittent buzzing alert from the ups when power is out and they are on backup. The video suggested they were going to cover killing that and replacing it with a light or something, but they didn't.

I probably should have used a fuse, and am going to splice ones in now thanks to the vid. The battery box is a great idea too, even with SLA's, to keep the cat off them etc.

The main thing is to keep all metal connection area protected with atleast electrical tape if not using a box. And one battery can only backup one ups (this from experience )

I've used car batteries for a number of years before getting the sla's in '05 and they worked great, altho there is the gas that emits when charging, and they water/acid to worry about as well, so sla's are a much safer choice.

(I also have a smoke alarm above them.)

By one battery only works do you mean that putting them in parallel does not work so well? Is it because it can't charge them equally? I was thinking of how cool it would be to setup an expandable system where I can just keep adding more batteries as I get money. Though really think one is enough, not like we get outages often.

I was also thinking of enclosing it in a box like they did, and have two pex tubes going outside for venting. Need to find a way so one is "in" and one is "out". Maybe a tiny fan or something.

Really in the future I would like to build a UPS that can handle a couple KW, and just run a whole sub panel off it. I doubt it would be cheap to build that though.

 

[Rubycon]

First car batteries are NOT meant for cycling use! You need an AGM battery designed for deep cycle use. The charger in the UPS may or may not like this.

Even more important is these units have inverters designed for intermittent use. They DEPEND on their internal batteries becoming exhausted in just few minutes under full load conditions. When this does not happen their components heat to beyond maximum safe operating temperatures and you better hope the fuse opens!

This is not a simple cut and replace mod - IF you value your personal safety.

 

[mpilchfamily]

They don't even use Sealed Lead Acid batteries, what's up with that.

I%

They where going for a cost effective solution. Sealed Lead Acid batteries cost more.

 

[Gillbot]

http://www.cryo-laboratory.com/foru...on/12947-got-bored-attacked-my-ups-today.html

Not advisable but it CAN work.

 

[Modelworks]

Done it for a long time but not with car batteries, marine batteries. And you usually need at least 2 for 24VDC, some of the bigger units require 4 for 48VDC.
I am not using the standard best buy UPS though but the rack mounts that are designed to run as long as you can provide battery power. they have fans in the back as well as connectors for extra battery packs
like this one:

 

[Red Squirrel]

http://www.cryo-laboratory.com/foru...on/12947-got-bored-attacked-my-ups-today.html

Not advisable but it CAN work.

Wow so he just hooked it up straight. I did not figure it was that easy. Though I'd be curious to know how well it works in the long run. No point in doing it if the trickle charging eventually overcharges and kills the battery. Think I'll give it a try though, can't hurt. May as well put that APC into production. Just need to find a proper way to vent the battery, preferably outside.

 

[Red Squirrel]

Done it for a long time but not with car batteries, marine batteries. And you usually need at least 2 for 24VDC, some of the bigger units require 4 for 48VDC.
I am not using the standard best buy UPS though but the rack mounts that are designed to run as long as you can provide battery power. they have fans in the back as well as connectors for extra battery packs
like this one:

Hmm not bad, good to know it works. I'm sure the charging circuitry of those rack mount units is better then a <100$ ups too. The APC I got is somewhat enterprise grade so maybe I'll have a good chance.

 

[MarkGinger]

Hmm not bad, good to know it works. I'm sure the charging circuitry of those rack mount units is better then a <100$ ups too. The APC I got is somewhat enterprise grade so maybe I'll have a good chance.

Hey Guys,



I know of a few installations where external deep cycle marine batteries were attached to a Smart UPS 1400 successfully. The run time is increased exponentially but the recharge time is very slow. Personally, I wouldn't go with anything over 12v 75ah x2. I can vouch that it works, have seen it with my own eyes.


M

 

[Red Squirrel]

Hey Guys,



I know of a few installations where external deep cycle marine batteries were attached to a Smart UPS 1400 successfully. The run time is increased exponentially but the recharge time is very slow. Personally, I wouldn't go with anything over 12v 75ah x2. I can vouch that it works, have seen it with my own eyes.


M

Yeah I would imagine the recharge time to be much slower. My concern would be overcharging though, or do decent UPSes detect when the battery is fully charged, and stop charging?

Also is a single deep cycle marine battery safe inside the house as far as the hydrogen gases go or should it be vented outside?

 

[Gillbot]

Wow so he just hooked it up straight. I did not figure it was that easy. Though I'd be curious to know how well it works in the long run. No point in doing it if the trickle charging eventually overcharges and kills the battery. Think I'll give it a try though, can't hurt. May as well put that APC into production. Just need to find a proper way to vent the battery, preferably outside.

That he would have been me since that is MY build thread, and that car battery lasted well over two years then was put back into a car for use. :biggrin:

I've been meaning to get a good deep cycle and hook it back up, I've just been too cheap to go buy a battery.

 

[Red Squirrel]

That he would have been me since that is MY build thread, and that car battery lasted well over two years then was put back into a car for use. :biggrin:

I've been meaning to get a good deep cycle and hook it back up, I've just been too cheap to go buy a battery.

That is definably good to know, I figured there might be a "catch". Think I'll go ahead and go find a deep cycle marine battery next time I head to Canadian tire. Any specific brands / attributes you recommend I look for?

 

[Gillbot]

That is definably good to know, I figured there might be a "catch". Think I'll go ahead and go find a deep cycle marine battery next time I head to Canadian tire. Any specific brands / attributes you recommend I look for?

Optima is a good known brand, aside from that I have no idea.

 

[Modelworks]

You can probably get by with car batteries, it really depends on how often the UPS has to use the battery. Here the power flickers about 2-3 times a week so I prefer marine batteries.

The UPS will not overcharge. Mine actually charges the batteries better than the stand alone charger. After a power failure if I listen closely I can hear the charging circuit make a humming sound, then as it finishes the charging I can hear it cycle on for about 5 secs then off for 5 secs meaning it is topping off the charge.

Batteries , marine included do release hydrogen when charging but it is very very small amounts when charged properly. If you overcharge a battery then you can produce lots more hydrogen and that also will kill the battery. If you think about it , maintenance free batteries would not last long if they constantly lost electrolyte from converting it to hydrogen.

 

[NeoPTLD]

The float voltage is higher on AGM SLA than flooded battery. APC runs about 13.9V per 12v battery. You can't tweak the float voltage with pots on newer models, so you'll have bubbling batteries.

Just get the proper batteries.

 

[Shaotai]

We're running two dell servers, 19" LCD and some networking equip at a friends house with two Optima yellow top deep cycle batteries hooked up in series. This UPS required 24v, so we needed two. Works great, plus they have a backup generator too which is online and will start up. They have a T1 running to the house, which hosts a webserver and their online business. that was a pretty fun project.
The optima yellow top is perfect, because it's a sealed gel battery, so no fumes.

 

[wwswimming]

First car batteries are NOT meant for cycling use! You need an AGM battery designed for deep cycle use. The charger in the UPS may or may not like this.

Even more important is these units have inverters designed for intermittent use. They DEPEND on their internal batteries becoming exhausted in just few minutes under full load conditions. When this does not happen their components heat to beyond maximum safe operating temperatures and you better hope the fuse opens!

This is not a simple cut and replace mod - IF you value your personal safety.

you're definitely playing with fire.

we had a short on a UPS at Elgar when i worked there. came down to the lab and there was a major smoke smell. 18 car-size batteries shorted at once on a military UPS (they make test benches for aircraft carriers, and the test-benches have UPS').

it was like that scene in Terminator 2 when Arnold & the guy chasing him time-teleport in a sphere-shaped energy ball, which vaporizes everything it touches, leaving a circle in the chain link fence (in the movie).

when the UPS shorted - with that many batteries driving it - it vaporized a spherical area the size of a soccer ball. everything - circuit board, steel standoffs, aluminum chassis, copper wires - was gone & splattered. most impressive but no good to breathe.

management bastards kept the manufacturing workers indoors to breathe the fumes, instead of calling a time out for 2 hours to clear the building of the smoke.

 

[MarkGinger]

Yeah I would imagine the recharge time to be much slower. My concern would be overcharging though, or do decent UPSes detect when the battery is fully charged, and stop charging?

Also is a single deep cycle marine battery safe inside the house as far as the hydrogen gases go or should it be vented outside?

Yes, the recharge time is definitely much slower. The UPS should know when the battery is fully charged. Sealed lead acid batteries are safe to use in doors, but you should definitely check with the vendor before buying the batteries. Car batteries are definitely NOT Safe to use indoors.

 

[Miramonti]

By one battery only works do you mean that putting them in parallel does not work so well? Is it because it can't charge them equally? I was thinking of how cool it would be to setup an expandable system where I can just keep adding more batteries as I get money. Though really think one is enough, not like we get outages often.

I was also thinking of enclosing it in a box like they did, and have two pex tubes going outside for venting. Need to find a way so one is "in" and one is "out". Maybe a tiny fan or something.

Really in the future I would like to build a UPS that can handle a couple KW, and just run a whole sub panel off it. I doubt it would be cheap to build that though.

Attaching the same battery to two UPS' at the same time didn't work. I thought I could save some money by going with just one battery for two units, but iirc the buzzers went berserk. I'm not entirely sure why tho.

Overall I've been doing this for about 6 years, 4 with sla marine batteries, two with car batteries. While they may not be made for deep cycle, I've never actually deep cycled them either and probably 30-60 minutes at the most.

Problem is that I depend on the internet for work, and whenever the power has gone out for long periods, the internet connection has usually died as well due to local servers or switches dependent on the same grid and not being on a backup system, so I go offline anyways. Given the annoying buzzing that I've never fixed, I usually just shut things off (especially after work hours.)

 

[Miramonti]

Done it for a long time but not with car batteries, marine batteries. And you usually need at least 2 for 24VDC, some of the bigger units require 4 for 48VDC.
I am not using the standard best buy UPS though but the rack mounts that are designed to run as long as you can provide battery power. they have fans in the back as well as connectors for extra battery packs
like this one:

Any product info on something like this would be great. Maybe worth looking up on ebay.

 

[MagickMan]

I'm reviving this thread to ask if this would be ok to use with my aging Tripp Lite UPS (a Smart1000LCD).

12V 33Ah Werker Deep Cycle AGM Sealed Lead Acid Battery

http://www.batteriesplus.com/produc...ed-Lead-Acid-Batteries/102645-Werker/12V.aspx

I can get one with a cosmetic defect for $50. Seems like a good deal and would last a lot longer than the battery that came with the UPS. Provided it doesn't destroy the UPS after 10 minutes on battery power...

 

[Gillbot]

theoretically yes, but you may burn up the charging circuit or etc. as has already been warned in this thread.