Battery charge dropping while connected to power mains

[theone]

I have an APC BR550GI Back-UPS ups.

I have fully charged a new battery with UPS turned off.

I then turned the UPS on and connected it to a constant load of ~60W.

UPS is still connected to AC power input.

After a couple of hours the battery is showing ~80% battery capacity.

How can this be? should the battery still be at 100% because at all times the AC input was connected?

This also happened to me with my previous battery - the UPS could not keep the battery charged while connected to the real load (PC). Battery would be completely drained over the course of a day although plugged into AC power.

Is there something wrong with the UPS?

[APC_Matt]

Hi

One thing worth trying is to put the back ups on battery and let it fully discharge and then charge up again.  It may need to calibrate so it correctly shows the battery capacity.

Regards

Matt

[theone]

Ofcourse I tried it.

The problem is that the UPS only charges the battery when truned OFF.

I did this and still UPS drains the battery over a few days with no load connected and AC mains on.

I also connected the battery after draining a 2nd time to an external dedicated charger and indeed it was amlmost empty so I don't think it is a calibration issue.

[APC_Matt]

Hi Theone

In that case can you contact the APC Customer care team in you region and they can organise a replacement

https://www.apc.com/uk/en/support/contact-us/   

Just change the country at the top of the page to the appropriate one and that will give you the correct contact information

Regards

Matt

[theone]

Even if not under waranty anymore?