Hi There.... I have had 2 powersures for awile - and decided to power them up..... Neither would come on. Do the batteries need to be charged, or replaced to make them work??? Thanks, J. Jeffrey

This normally happens when the reserve battery in the UPS has run out of power and needs to be replaced.

UPS come in two types, lower powered cheaper types are usually switch over power.
These units senses a power outage and then switch over to the battery power to generate mains supply. The switch over occurs in milli-secs and does not affect the computer.
True UPS types constantly run off battery power to generate mains supply so there is no switch over time lag. These units are higher powered and higher costs units.

Both type of UPS have the same components.
Battery charger.
Batteries
Inverter that converts battery voltage to mains voltage
Electronic controls

Yes, is the short aswer to your question. The battery should charge as you use the ups. If they don't then its likely the battery/s have failed. Lead acid batteries do not like being left discharged for any length of time. In a motor vehicle the battery gets a bit of shaking around, but in an ups they don't. If not used and left discharged, the plates quickly sulfate up reducing the efficiency to nearly zero. Test and replace any battery that cannot support a test load, such as a bright12v light or a 12v soldering iron connected to it. The length of time required to charge the battery/s depends on their capacity (in ampere/hours) and the charging rate. A 14.4 amp/hr battery charged at say 1 ampere will take 14-1/2hrs to charge.(just as a sample)

ITS WILL BE CORUPTED

maybe the batts are dead or you have failed cell or bloc.

check the batts, unit will not start without good batts charged

Try to change your batery..

chek the power transistors.

How does it react when you simulate a power lose? Unplugg it from the wall to test it to see if it turns to battery power. If the unit goes to the battery backup normally then check to see if it has a reset button on the unit. Please let me know what size unit it is.

the battery is bad, you will need to replace the battery or the whole unit. you can find batteries on ebay. just source the model number. also depends on the size of the unit. you may need to just replace it...just a better value to do it that way.

good luck
K.