I have a 2000VA ups that contains 2 batteries ( 12V 9Ah ). I think that something happened to the batteries, since now they can barely handle an average laptop for about 3 minutes before shutting down the whole ups. there is any way to resurrect the batteries, or should I just buy new ones?
closed as off-topic by Kaz, Daniel Grillo, placeholder, Chetan Bhargava, Nick Alexeev♦ May 26 '14 at 21:20
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." – Kaz, Daniel Grillo, Chetan Bhargava, Nick Alexeev
UPS batteries usually do not last much more than 3 years, it's that easy really.
To check the battery or batteries: As your UPS is a large one I'm assuming that it is actually has a separate battery compartment which you can access without dissembling the whole thing.
Connect as many batteries as you need in series to get 12V and load test it which a common 12V lamp.
Charge the 12V pack with a normal automotive charger. As there most likely are several batteries in that UPS, repeat for all batteries.