Yet an other UPS question

I have a PCM 650VA UPS with a small battery (7AH) which give about 5 mins backup time. I was wondering if I can attach a bigger battery for longer backup time (about 1 hr). has any one tried this here? of course this would mean getting more powerful charger for the battery but as far as i have read they require deep cycle batteries which are really expensive. i would like to hear from some one who have actually succeeded with the Volta/Osaka UPS batteries.


bump.... any one?

just don't do it these osaka volta batteries are not reliable and you will end up with the blown circuitry due to heavy current drawn by these big batteries, they tend to take around 18 amp initially to charge when they are drained and with the time the drawing current started to decrease even then its 8 to 10 amp which is alot.

Well this is not related to the original question. But is yet another ups question.

I have a local ups. This is my second one. I have noticed that circuit board of these local ups have three variable resistors.

Can anyone please explain the settings these three do?

for sure you can attach the bigger battery BUT never let the battery drained completely ,


if u have a separate charger then charge this bigger battery from tht external charger ( u can buy it from the market easily ) dont forget to turn OFF the UPS and disconnect the terminals attached with the battery before charging the battery FROM EXTERNAL CHARGER.

i have done this for n experiment in my driver house :) and alhamdoLILLAH it is successful , remember if the battery is drained completely your builin (jo ups main hai) charger cannot charge the battery again as it is designed to charge the same battery which is given with the UPS (stock one).

The orignal charger suck i believe. 7AH battery and its taking 6Hrs to charge to 90%? common man with which current its charging the battery? roughly estimating 7Ah/6= 106.6mA?

Is this the current to charge a battery or its a current to run the circuitary?:)

Nadeem is right, u can only use external charger. with ur orignal charger, the charger will eventually burn out, due to long charging and even if it doesnt, it will never charge u battery to a certain level considering the load shedding in our city. and this will ruin your battery.

a simple way to convert any Squar wave (desi/imported) UPS into Sine wave UPS. i tried it with my APC-500 old UPS it worked great. guys don't waste money in buying expensive sine wave UPS