# APC UPS Battery charging



## benh (Jan 13, 2006)

I have an APC Smart-UPS 1400 SLA battery pack, part number RBC7. It's brand new in box, but about 4 years old.

I'm hoping to use this battery as backup DC power for power outages and have some questions:

1. Since this is an unused battery, do you figure it's dead or is it problably still good? Any way to check?

2. How can I charge this battery, assuming that I don't have a 1400 series UPS to charge it with?

3. Any idea what voltage and amperage this guy is? the box says it's 2 12V batteries, 17AH. Not sure if that's then 24V at 17AH or 12V at 34AH. The interconnects between the two batteries are sealed up, so I can't see if it's serial or parallel.


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## benh (Jan 13, 2006)

I got it home and stuck it on the multimeter and it's reading 24.9 VDC. After 4 years sitting in a box in a closet with no power to it. That's pretty neat.

So I guess it's wired in series then, 24 VDC at 17AH. I suppose I need some way to step the voltage down to 12VDC so I can use it. Or, I suppose I could crack open the wiring covers and rewire it in parallel and have a nice 34AH 12VDC battery pack. Still have to figure out how to charge it and how to evaluate the overall health of this guy.


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## KevinL (Jan 13, 2006)

It's pretty much an ordinary sealed lead acid (SLA) battery and a good SLA charger should be able to handle it. Off the top of my head I can only think of one, that's the famous Triton charge-everything-in-existence charger, but it's a bit pricey. 

The plus side is that you can use the Triton to charge just about every other NiCad/NiMH/lithium ion/lithium polymer battery. It's truly the do-everything charger.


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## wquiles (Jan 13, 2006)

KevinL said:


> The plus side is that you can use the Triton to charge just about every other NiCad/NiMH/lithium ion/lithium polymer battery. It's truly the do-everything charger.


Indeed - that is why I like mine so much. ONE charger for everything 

Will


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## benh (Jan 14, 2006)

I'm guessing my car battery charger won't work. It's not particularly fancy.


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## Flash_Gordon (Jan 14, 2006)

benh said:


> I'm guessing my car battery charger won't work. It's not particularly fancy.


A regular car battery charger is not recommended. Usually too much current and not smart enough.

I do a lot of field work where we use SLA batteries to power test instruments. We use multiple 10 bank chargers by Battery Tender. They also make smaller and cheaper single battery chargers. 

For this type of battery you want to keep the charge current low in the 1-2A range and use a smart charger. This type of charger can also be used to charge or maintain your vehicle type lead acid battery.

Battery Tender


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## turbodog (Jan 14, 2006)

Those batteries are ok to charge with a regular car charger IF you stay at 1-2 amps. And, do not leave it on the charger once it's full.

Take a screwdriver and pry up the plastic covers at each end. They are just held in place with double sided sticky tape and should come up pretty easily.

After that, you're set to unscrew the connectors between both batteries.

I would then try to separate the batteries themselves. They are held together with sticky tape also. Take a bare hacksaw blade and slip it between them. Start sawing a little. You should start to see tape come out. Pry A LITTLE with your hands and keep lightly sawing. It you get plastic coming out, stop. You're sawing into the cases themselves if this happens.

These batteries are worth about $110-140 together when new. I should know, I just ordered $2000 worth of them on Friday.

Or, you could just buy the ups they fit. Used apc smartups 1400/1500 are available all over ebay for $100 or so.


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## benh (Jan 14, 2006)

I have a Schumacher "fully automatic" 12V car charger with a selectable 2A and 10A charge modes. The 2A is tagged as a trickle charge. It has a capacity meter as well.

Think that'll work ok?


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## Flash_Gordon (Jan 14, 2006)

benh said:


> I have a Schumacher "fully automatic" 12V car charger with a selectable 2A and 10A charge modes. The 2A is tagged as a trickle charge. It has a capacity meter as well.
> 
> Think that'll work ok?


You might want to read this FAQ to help in your decision.


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## benh (Jan 15, 2006)

I ended up ordering a Triton charger. It wasn't significantly more expensive than a decent dedicated SLA charger and it'll charge just about everything, looks like. 

And towerhobbies.com had a $25 off $149 coupon code, so I got the charger, thermal probe and a couple sets of charging leads for $130.00 or so shipped.

This will be cool because I have a couple of older batteries for a Libretto that I might be able to bring back to life.


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## KevinL (Jan 15, 2006)

:twothumbs:


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## snakebite (Jan 15, 2006)

benh said:


> I ended up ordering a Triton charger. It wasn't significantly more expensive than a decent dedicated SLA charger and it'll charge just about everything, looks like.
> 
> And towerhobbies.com had a $25 off $149 coupon code, so I got the charger, thermal probe and a couple sets of charging leads for $130.00 or so shipped.
> 
> This will be cool because I have a couple of older batteries for a Libretto that I might be able to bring back to life.


the best you can hope for on the libretto batts is the electronics are ok and you can install new cells like i did.when a li-ion cell is dead there is no reviveing it.
btw great portable wardriver!


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## Christoph (Jan 15, 2006)

I just got this from a sprint service guy it's not too old and it is heavy but what capacity  125 ah you just need two men and a small boy to transport it:laughing: 





http://img75.imageshack.us/my.php?image=flashlightpics0534bq.jpg



C


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## benh (Jan 15, 2006)

I'm going to have to hit up my telco guy for a battery like that! Wow.

That Libretto is a great wardriving machine. That's actually exactly why I got it. I'm thinking of getting rid of it, though, because I have a Vaio now that should be just as good, if a bit faster.

I'm now looking forward to cycling my DeWalt drill packs to see if I can improve them somewhat. This is addictive.


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## benh (Jan 18, 2006)

Weirdness. I got the Triton charger this afternoon and I have it hooked up to one of the 12V 17ah batteries. I set the Triton to lead acid battery type, 12 volts, with a charge rate of 1.4A.

It's sitting here charging, and the voltage displays 13.16V and the charge rate is currently displaying .2A. Occasionally, the charge rate drops to 0 and the voltage readout drops to about 8V, then it kicks back in at .2A and reading 13V.

Is this normal?


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## benh (Jan 25, 2006)

So a little knowledge is dangerous, and in that spirit, I have more questions.

I've split the battery pack into 2 12V 17Ah batteries by unbolting the connectors and managed to unstick the two batteries from each other without damaging anything.

I've been heeding the advice in this thread to charge these SLA batteries at a current between 1 and 2 amps, and it's taking forever to charge even one of the batteries. The first one is going on 24 hours now and it's still only at about 5000mAh of capacity, according to the Triton charger's readout. Oddly, even though I set the charge rate at 1.4A, the Triton has elected to spend most of its time charging it at .1A, which probably accounts for some of the long charge time.

I've been reading the tutorial on Battery University, and that document says that small SLA batteries can typically be charged at a rate between 10% and 30% of rated capacity, which works out to a rate of 1.7A to around 5A for a 17Ah battery, if I did my math correctly.

So my questions are these:

Anyone know why the Triton charger is choosing a different charge rate than I specified? I read through the manual and didn't find anything that seemed relevant.

Would it be safe to increase the charge rate to 3 or 4A?

Thanks for any pointers.


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## snakebite (Jan 25, 2006)

benh said:


> So a little knowledge is dangerous, and in that spirit, I have more questions.
> 
> I've split the battery pack into 2 12V 17Ah batteries by unbolting the connectors and managed to unstick the two batteries from each other without damaging anything.
> 
> ...



set the triton to its highest discharge rate and a cutoff of 10.5v.
if it drops dead the instant you start the discharge the batts are shot.
might float them at 15v a few days to run off any sulphation.
a sla will rot on the shelf and that may be whats wrong with yours.
and last year at hamvention a guy had 10 of those telecom batts with 2002 datecodes he had trouble selling.i looked at them for my solar setup and as soon as i was seen as interested he told me they were free if i could carry them off.5 trips with one on each shoulder later they were mine.nothing wrong with them.the odd shape limits their usefullness for many apps which could be why at 20.00 ea he couldnt sell.
i was about to pay him when he offered them free.


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## LitFuse (Jan 25, 2006)

Hey Ben, I think maybe one (or both) of your batteries are toast. 4 years is about the average lifespan for this type of battery I think. They could be heavily sulfated or have a bad cell in them. Load testing them would be the first thing I'd do, to see if they hold their voltage with a load applied. An automotive type load tester could be used, or a DMM in combination with some sort of high amp DC load.

Peter


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## LitFuse (Jan 25, 2006)

Or the Triton itself, as snakebite wisely pointed out as I was typing my reply...  

Peter


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## benh (Jan 25, 2006)

Hmmm. 23 minutes at the highest Pb discharge rate the Triton would allow to a limit of 10.8 volts (again, closest to 10.5 without going under that number) and when it was done, the battery read 11.45 volts according to the Triton and 11.34 according to the multimeter I had connected at the same time. 

That's on the battery that's been charging for 24+ hours and was only at about 5000mAh.


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## vandrecken (Jan 25, 2006)

For generic stuff on Sealed lead acid's try the yuasa website.

SLA's will typically be supplied ex factory with a part charge to protect them in storage. This will decay and the battery will be damaged if it's left sitting uncharged.

Battery life varies according to their design, storage conditions, and usage conditions - like cyclic or float applications.

I'd expect yours to be damaged just from the length of time they''ve been sat - Sorry !

One extra option for chargers: performance motorcycles these days use small gel batteries that easily run down if they're left to stand for a couple of weeks with a burglar alarm active. Smart chargers are specially made to deal with this problem and can can do battery diagnosis, charging at typically a couple of amps, and then maintain the battery not by constant float charging but by monitoring voltage and pushing in a 2 amp top up charge whenever the battery voltage falls below a target value. I've used one of these on a 12v / 17a/h pack recovered from a fire alarm system and it works fine.

Cheers,


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