Hi,
I had posted this question about ten months ago. Now I just wanted to 
update with the status if anyone is interested.
I have had my UPS connected with four wet cell automotive 65Ah starter 
batteries for a year now and they have been exercised fair frequently. 
For the past few months, due to heavy electric load shedding, they have 
been working really hard and they get discharged by about 70% of full 
charge three times a day. I do have to add to the battery water every 
couple of moths which is a real pain. I am happy to report that the 
batteries and the UPS are doing just fine.

On 4/30/2009 11:45 PM, Bob Blick wrote:
> Hasan A. Khan wrote:
>
>    
>> I recently purchased a used APC SmartUPS 2200VA UPS at a dirt cheap
>> price.  It was cheap because its batteries were near the end of their
>> life.  Replacing the batteries with the same kind of dry cell lead acid
>> is prohibitively expensive here.  I was thinking I would replace them
>> with ordinary wet cell automotive batteries because they are really
>> cheap.  These wet batteries are not the maintenance-free type and they
>> won't obviously fit in the casing.  I will have to keep them watered but
>> that's ok by me.
>>
>> My concerns are: is there a charging cycle difference between the two
>> types of batteries?  Will the charger in the UPS work OK?  Any danger of
>> batteries getting burnt or exploding?  I did some search on Google and I
>> could only learn that UPS batteries are deep cycle while automotive
>> batteries are not.  Will that have any negative effect on the UPS?  Any
>> help is appreciated.
>>      
> Hi Hasan,
>
> Sealed lead-acid batteries are more fussy than liquid electrolyte types.
> So I think you should have no problem electrically using wet cells.
> Automotive batteries can take fewer deep discharge cycles, but unless
> you frequently run the UPS flat I see no problem with lifespan.
>
> But please be aware that if you mount the batteries externally, unsafe
> voltage will probably be on one or both of the terminals, 240 volts is
> quite possibly connected to one terminal depending on where ground is
> referenced.
>
> Being "wet" cells the surface of the batteries may also have high
> voltage that can cause accellerated corrosion to anything they are in
> contact with. Putting them in battery boxes is a good idea. Or at least
> "non flammable" picnic coolers or plastic storage tubs. :)
>
> Cheerful regards,
>
> Bob
>    


-- 
* -Hasan *
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