# apc 2200xl batteries

Hi All,

If I want to add external batteries to my apc 2200xl will it work?

Assumptions
*Assume the new batteries are large capacity
*The correct internal replacement batteries are \$267 4x(18ah 12v)=72ah or \$3.7/ah

Questions:
*My guess is if the capacity is 2x the recharge and charge time would be just under 2x (yes/no?)
*From the above is there a more cost effective battery \$/ah or should i just keep it as is

• Solar Expert Posts: 10,300 ✭✭✭✭
Re: apc 2200xl batteries

now that's a good question. it would depend mostly on the ups' ability to charge the higher capacity batteries. you may want to measure the charge current going into the 4 batteries you had used to try the unit. make sure the batteries have used some current to allow the full charge to take place. generally we like to give batteries between 5 and 13% of their rated capacity to charge them. guesing here, if they were being given say 2 amps for 18ah batteries that equates to about an 11% charge rate, but to give batteries that are 100ah that same charge current it is 2% and that is too small to properly charge the larger ups batteries then. you may get away with a charge rate as low as 3%, but know that it will take much longer to recharge. all of this is uncertain until you know how much current that ups can deliver.
btw, i assume those batteries are wired in series and the current capacity will not add in series, but rather will stay the same for it is the voltage that adds in this case. 4x12v=48v at 18ah.
Re: apc 2200xl batteries

Hi Niel,

Is ah=ah?
let me make sure I understand is AH all equal? ie is 10ah at 6v = 10ah at 12v? or is it 6v*10ah=60 watts/hr where 10ah at 12v=120watt/hr?

Math on charge rate
I'll check the amps for charge on the ups (CU) then if depending on the answer from above calculate to see the max AH that can be charged where: (ups amps)/(AH batteries) is >5% and < 13%

lastly is there a good article describing how to hook up power in to this existing system (genset, solar, wind, ups charge from utility, etc)

thank you!
• Solar Expert Posts: 10,300 ✭✭✭✭
Re: apc 2200xl batteries

sorry as ah is ampere-hours. putting a battery in series with another battery will only add more voltage. the current stays the same in series. in parallel the current adds and the voltage would stay the same.

"lastly is there a good article describing how to hook up power in to this existing system (genset, solar, wind, ups charge from utility, etc)"

i thought we were discussing using only the built-in charger on the ups, but if you attach solar, generators wcharger, etc. then that changes the whole thing as you'd then be able to go as large of an ups battery bank as you'd wish providing you can supply the necessary charge current rate for them.
• Solar Expert Posts: 741 ✭✭
Re: apc 2200xl batteries

I went for two years with a upgraded battery bank using a ACP Backup Pro 1000. Went from the stock 17AH x 2 batteries to 55 AH x 2 batteries. I think it took a extra hour or so to recharge the larger set. If the battery bank is used every day, then the 13% rule would applied. If used ONLY for power failures, then I think you can get away with lower %.
Re: apc 2200xl batteries
0000jimmy wrote: »
Hi All,

If I want to add external batteries to my apc 2200xl will it work?

Assumptions
*Assume the new batteries are large capacity
*The correct internal replacement batteries are \$267 4x(18ah 12v)=72ah or \$3.7/ah

Questions:
*My guess is if the capacity is 2x the recharge and charge time would be just under 2x (yes/no?)
*From the above is there a more cost effective battery \$/ah or should i just keep it as is

Yes it will work, that model of UPS is designed to be used with external battery packs. If you plan on using AGM batteries you will be able to charge the batteries with the UPS' built in AC charger connected to the AC power. If you plan on using FLA batteries you must use an external charger because the charging requirements are different for each type of battery; your UPS is not designed to charge flooded batteries. You can replace the piezo beeper with a 150 ohm resistor to silence the alarm when on battery.

My initial system was a SmartUPS 1000 with eight Trojan T-105's (420ah) charged with my solar array and MX-60. I used it for emergency power and to run a little window A/C unit. It probably saved me \$2.74 worth of grid provided electricity but I guess we all have our hobbies :-)

Cheers,