Low Battery Runtime Minutes Displayed With New Battery

[jcahow]

I purchased a new APC RBC123 (12V 7Amp) battery for my Back-UPS NS 1250 BN1250G UPS and it only shows 48 minutes of run time with nothing attached.  This seems quite low as my similar APC Back-UPS XS 1300 UPS shows over 200 minutes of run time with nothing attached with the same battery model.  The APC site shows comparable battery life for these two models so I do not understand why the NS 1250 is so much lower.

Now I should mention that I had a spare RBC124 battery (12V 9Amp) which is identical in shape that I tried first in the hope of getting longer batter life.  These RBC124 batteries are what goes in my larger Back-UPS XS 1500 UPS which shows 262 minutes of run time with nothing attached.  At that time I only saw 45 minutes of run time and I saw others that experienced the same issue with lower run times using the RBC124 instead of the RBC123.  I then tried the new RBC123 battery and it went up a few minutes but no where close to where I think it should be (200+ minutes).

So I am unclear if using the RBC124 battery first damaged the UPS or whether there is something left over from the RBC124 battery use that needs to be cleared out or whether something else is going on.  I bought the NS 1250 used years ago and the battery was practically dead when I just changed it so I do not know how many runtime minutes it showed when I got it (maybe it never showed more than 40 some minutes).

Has anyone else seen anything like this or have any suggestions?

[jcahow]

I got no reply here so I contacted APC support directly.

It seems that they think inserting the higher Amp battery possibly damaged something internally and cannot be corrected.

I have two similar APC UPS devices the 1250 mentioned above and a Back-UPS 1300 that both exhibit this same issue after putting 9A batteries in 7A units.

They both seem to still work but only show 45 minutes of run time instead of 200+ minutes with a new battery in them.  I thought the display might just be showing a low number but when disconnected from power they immediately start to count down from 45 minutes (instead of holding there for some time).

Personally I told them that their battery design was atrocious in that the 7A and 9A battery backs are identical in form, size and color and they should be designed so that they only fit in the appropriate devices (especially if the 9A can damage 7A devices). 

They are already designed to only go in one way so why not design them to only fit the correct devices?