Hi, 

I have a small 650va Eaton ups. 

I use this to power the TV, decoder and WiFi routers during load shedding. 

The standard 7ah battery is on its way out. It used to power this setup for 30 minutes plus, but now barely last a minute. 

Could I replace the battery with a Bluenova or Freedom 12v lithium battery of the same or larger capacity. They sells these as drop in replacements for alarms, ups's etc. This would obviously use the internal charing circuit of the ups/alarm. 

Would this work optimal or would the voltages be too far out of wack? 

3 hours ago, TheoVogel said:

Would this work optimal or would the voltages be too far out of wack? 

The voltage will be fine. That's usually the bare minimum required to qualify as a "drop in replacement".

3 hours ago, TheoVogel said:

same or larger capacity

A larger capacity might be a problem. Many cheaper UPSes (I don't know if this is one) have insufficient cooling and rely on the small battery running out before they overheat. If you upgrade the battery, they may well overheat. One way to get around that is to not use the full capacity of the UPS. You may have to do a test run to see how hot it runs.

Finally, also remember that many UPSes (and alarms, electric fences, etc) recharge really slowly, so a bigger battery also comes with the added problem that the original charger in that device has a hard time recharging it. If you cannot fully recharge the battery within a couple of hours, the bigger battery might be of no use.

Thanks for the info. The ups seems to charge at around 1 amp, so it will take around 2 days to fully charge a 44ah battery.  Would it be possible to add an additional charger with the ups or paradox alarm built in charger? 

8 minutes ago, TheoVogel said:

additional charger with the ups

Yup, that is usually what people do.

8 minutes ago, TheoVogel said:

paradox alarm built in charger

Paradox alarms have a setting for increasing the charge power, though I'm not sure if it goes to more than 2A. So the same fix will probably be required.

The Blue Nova 8Ah LiFePO4 Lead Acid replacement battery according to their spec sheet has the following Discharge Current ratings.1.44 A continuous and 7.2 A burst (30 seconds). This battery will not work well in your UPS if drawing more than 93W for 30 seconds during grid failure.

15 hours ago, acs said:

7.2 A burst (30 seconds).

Mmmh... well that makes it kinda useless for a gate motor. These Centurion gate motors (quite popular in my area) don't have a large enough power supply to carry the peak current, so they use the battery for that peak. It can draw over 10A for several seconds.