Remaining Battery Charge down to 56% after 1 hour

[Anonymous user]

Hi,
My customer have APC Back UPS Pro 1500 with External Battery Pack.

It was connected to electric network on input for a few weeks with close to zero output load therefore it was fully charged. PowerChute showed 99% charged.

Then I unplugged it from electric network on input and also disconnected all output load.

After an hour in stand-by I have Remaining Battery Charge on 56%.

After an hour and a half it is on 50%.

After two hours it's on 10% and after two hours and ten minutes it's on 0%.

Is this as it should be? I think it is not.
The device was produced 16 months ago and is in active use 11 months.

Any thoughts/advices what could be the cause of this strangely fast discharge?

Thanks.

Robert

[APC_Matt]

Hi Roberz

It may not be giving you an accurate remaining battery charge with no load.

I would recommend giving it ~15% load and see if it behaves as you'd expect.

Regards

Matt

[Anonymous user]

Hi Matt,

Thanks for your input.

I already did - well - kind off. I put my laptop on output side which accounted for 20 - 25 Watt load. I'm not sure if this was 15% you mentioned. Actually I'm not sure what are you referring to when you say 15%? 15% of what?

When I loaded my laptop on output Remaining Battery Charge dropped down very fast (40 minutes) so I made a zero load test which I mentioned in my first post.

[APC_Matt]

Sorry I should have been clearer

15% of the maximum power capacity 865W, so your laptop would be ~ 2%

We often use a basic lamp to test the runtime in our office, with low loads often what is displayed as the remaining runtime or battery capacity is different to the actual runtime you get when on battery.

[Anonymous user]

Thanks Matt.

I did as you proposed:

1. Fully charged UPS and Battery Pack

2. Loaded it with 120 W of power consumers

3. Measured power drainage.

It was as follows:

Time           Remaining Charge

0:00            100%

0:03              64%

0:05              50%

0:10              10% and PC hibernation initiation

Therefore in 10 minutes I was out of remaining charge when loaded 1500 VA UPS with 120 W.

This shouldn't be normal. Where should I search for solution?
Thanks.