APC UPS Battery Backup Mod

Posted by: oojacoboo

APC UPS Battery Backup Mod - 02/28/08 06:30 PM

OK, so, I have an APC UPS Pro 1000 (aka 1kva). So, the battery has just died on it, and I am thinking I will just connect up a deep cycle marine battery. However, I am wondering a few things.

Does the onboard computer have a memory of how much voltage is in the battery, or does it actually take direct readings? So, in other words, if I hook up a battery to the UPS, will I get the full battery power, or will I be limited to the same capacity of the current battery?

Also, any recs on the casing? The one I have now won't fit a large deep cycle marine battery...

I was also considering hooking up 2 or more batteries in a parallel circuitry. Does anyone foresee any concerns with this?

Any and all tips and recs appreciated.
Posted by: whitlock

Re: APC UPS Battery Backup Mod - 02/29/08 08:10 AM

I think those suckers take readings of the voltage, though if it's higher or lower than the stock battery it may freak out and not properly condition power / recharge if there is a failure. Not really a memory issue, but how the hardware is on the board.

It's worth a shot if you have a spare laying around. Worst thing that can happen is that it fails... well that or explode. I suppose exploding would be the worst.

If it doesn't work, call a battery store and check how much a new cell at that range would cost.
Posted by: BigO

Re: APC UPS Battery Backup Mod - 02/29/08 11:09 AM

Originally Posted By: "whitlock"
Worst thing that can happen is that it fails... well that or explode. I suppose exploding would be the worst.

I think the worst would be if it turns into Venom and foils all your crime-fighting plans.

I think I need to get out more.
Posted by: Waragainstsleep

Re: APC UPS Battery Backup Mod - 02/29/08 01:08 PM

As I understand it, 'smart' batteries cannot measure the charge currently contained within themselves (there is something awful about that sentence, but I think its OK).

The charge is measured as it enters and leaves the battery. When you recalibrate a battery by charging it full, discharging fully, then charging fully again this resets the 'charge-o-meter' to 100%.
Thats how Apple laptop batteries work at any rate. If yours is as smart, it should be able to recalibrate itself to a new battery. I confess I don't know much about the variations of currents and voltages used to recharge batteries and their associated tolerances. I would guess that a nasty miscalculation of this is the sort of thing that could make a battery explode.
3rd party batteries with higher capacities seem to work fine with Apple PMUs, SMCs etc. As far as I know, the electronics are identical to Apple batteries but the actual cells are upgraded.
Posted by: oojacoboo

Re: APC UPS Battery Backup Mod - 02/29/08 02:15 PM

hmm, so...

Not really sure about this, I def am not looking to have an exploding battery... I don't think thats going to be the case, but at any rate, I wanna be sure that this will work.

Anyone with any experience on this?
Posted by: TCPMeta

Re: APC UPS Battery Backup Mod - 03/01/08 06:21 PM

You can use the battery but use a automotive 20amp fuse on the battery.
Posted by: oojacoboo

Re: APC UPS Battery Backup Mod - 03/01/08 06:41 PM

20 amps is the standard current for the electrical in your home?
Posted by: Waragainstsleep

Re: APC UPS Battery Backup Mod - 03/02/08 07:46 AM

20A is a reasonable and safe amount of power for pretty much any appliance(s) you might need. In the UK, you don't often see fuses over 13A in appliances, I think they go to 30A in domestic fuseboxes.
Posted by: TCPMeta

Re: APC UPS Battery Backup Mod - 03/02/08 01:49 PM

For 12volts most fuses are 7.5, 10, 20 and 30 amps. If you use something that needs a crap load of amps or wattage then 40 or 50 amp fuses are needed. For examples my carputer power supply uses a 10amp fuse and I also modded my gaming PC's power supply to use 10 amps for 12 volts and 7.5 amps for 5 volts for the DC outputs. My car amp uses a 40amp fuse for the main power but the amp has a 15 amp fuse. So if theres a power surge the 15 will blow first and if it effects my main power the 40amp will blow.

Your UPS is nothing more then a power inverter with a battery. It turns 12 volts DC into 120 volts AC. When it's plugged into the wall it's going into two way. Straight power to the device and also into a battery charger keeping the battery charged.

The UPS should have a voltage regulator so you shouldn't really even need a fuse but I would add one just for as a safety. Last thing you need is to test it or wait for a power outage and too many amps end up into the PC or even into the battery.
Posted by: oojacoboo

Re: APC UPS Battery Backup Mod - 03/02/08 07:13 PM

yea, so, I am wondering, I am probably draining some decent power here...

Mac Pro w/ 3HDs
4 LCD's
Cable Modem/Router
Backup 2-HD RAID Kit
MacBook
Printer
100Watt Lamp
iSub/iSticks

There are some other smaller things, but those will be the major power suckers...

So, you are recommending a 20A on the lead from the UPS to the battery? On the positive terminal, right?

If I run a couple in parallel, would you put one on each positive lead?
Posted by: TCPMeta

Re: APC UPS Battery Backup Mod - 03/03/08 06:21 PM

::blinks:: the battery would die with in minutes, 5 minutes max of power and that's if the charger keeps it really nice and charged. Best bet is to use a deep cycle Optima yellow top battery, it's used for high end audio systems in cars, also a capacitor would be needed.

Instead of 20amps go with a 40 or 50 amps. I would do parallel so you don't end up hurting other power devices.

Get rid of the lamp, cable modem/router and speakers. The UPS system is there so you can save your work and shut the system off, it's not meant to run the system fully off of battery like a laptop.

If thats what your trying then get a generator.
Posted by: oojacoboo

Re: APC UPS Battery Backup Mod - 03/03/08 07:22 PM

heh, yea. Well, I like the router/cable modem on there so I can shutdown the main rig and continue doing work from my laptop for hours. Since cable doesn't need power to be sustained, internet will stay up most all the time.

As for the light, I turn it off when power goes out. Its just nice to have connected so I can use it when powers out wink

As for the time being min, yes, I know, I get like 3 min now tops!

You mention a CAP. What would be the point? Isn't a CAP just a battery?
Posted by: TCPMeta

Re: APC UPS Battery Backup Mod - 03/04/08 04:49 AM

The cap takes the strain off the battery. Heres a example for a car.

Battery - Cap - Amp - Speakers

That's how most people do it. Now for my setup when I had the car running and before my carputer was stolen.

Battery - cap - carputer - Amp - speakers

The battery charges the cap and from the cap it goes to what ever device you connect it to that uses high amps and wattage.
Posted by: oojacoboo

Re: APC UPS Battery Backup Mod - 03/04/08 09:37 AM

I have installed CAPS before, and I am aware of how to use them. However, it was my knowledge that when the car is running your alternator is designed to push the electronics of your car at 14 volts. So, you have about 2 volts of extra there beyond keeping the battery charged. The purpose of the CAP is to handle the spikes needed by the amp at times when the alternator can't keep up. This keeps the car battery from dying and your lights and other electronics inside the car from being drained of the power they need.

Now, I don't understand how a cap is going to benefit me. As I understand, its just a small battery in the connection closest to the power source, to prevent drain on the alternator...
Posted by: TCPMeta

Re: APC UPS Battery Backup Mod - 03/05/08 05:03 AM

Most alternators these days have a voltage regulator that won't let you exceed over 12 volts. Lets skip the cap idea, I wasn't thinking correctly at the moment.
Posted by: oojacoboo

Re: APC UPS Battery Backup Mod - 03/05/08 04:22 PM

Wonder why your Voltage Meter on your gauges reads 14 then?
Posted by: TCPMeta

Re: APC UPS Battery Backup Mod - 03/06/08 04:55 AM

Mine reads 12.6volts and the voltage gauge in the car reads 12.

Anyway, after thinking about it would the APC be able to charge a car battery and keep it charged?
Posted by: oojacoboo

Re: APC UPS Battery Backup Mod - 03/06/08 09:37 AM

I don't know the answer to that... I don't know how the onboard inverter/charger is setup...
Posted by: oojacoboo

Re: APC UPS Battery Backup Mod - 03/06/08 09:43 AM

here is a good article...

http://catbear.livejournal.com/186573.html
Posted by: flippy10

Re: APC UPS Battery Backup Mod - 03/06/08 03:50 PM

I've done this mod. It's quite useful. I got 36 hours of power off of two wheelchair batteries wired in parallel. I mean... I was only running a laptop and an external HD.. so the draw was about 130W or so at load.