Battery Swelled up

[HobbyJeb]

I have a BR1500G that was acting like it had battery issues.

It's one of those that use two CP1290's connected together.

It looks like it's one big battery, but it's actually 2.

I had a spare battery, so I went to swap it out, and had a tough time getting the existing battery pack out of the unit.  After I finally got it out, I noted one of the 2 batteries was swelled up on all sides.

My question is, what does this mean? Was the battery defective? Was it over charging?

Basically is my BR1500G unit ok? Or was it the reason the battery swelled up?

[Teken · Accepted solution]

The answer depends upon many factors such as how old the UPS is and what firmware is present. As older units would not charge / float the RBC correctly over the long term.

It also depends upon what specific battery was installed in the unit as every cell has a different specification.

IE. Some cells have higher tolerances with respect to charging, float, operating temperature, cycles, resistance, and chemistry.

None of the photos you uploaded shows the actual battery maker.

As it relates to the cell being warped and swelled up. This indicates the system continued to charge the cell while ignoring it had failed.

Hence it’s imperative that you never rely on the Self Test as the final indicator as to a good / bad battery! ☝️

Only regular maintenance, inspection, and testing can affirm the RBC health.

If you had the proper equipment you would be able to measure the internal resistance of the cell. You would probably find the resistance to be extremely high or near a dead short.

Generally speaking the cell would show high internal resistance well beyond the manufactures specifications of 12 ~ 25 mOhms depending upon battery maker.

At this point your options are to simply replace the battery with a high quality (HR) cells such as CSB.

If the unit is more than five years old than it makes a lot more sense to replace the entire unit with a new one. As the operational service life of the current generation of APC Back-UPS is only 2-6 years.

NOTE: You must replace both cells that make up the RBC. If you only replace one cell you risk damaging the new cell once it’s been mated together.

Questions Ask . . . 👍

[HobbyJeb]

Thank you so much for the information. The unit is a 2018 vintage. The battery back was from 2022. The battery brand is Vision CP1290. Obviously, I know I needed new batteries. But I did not know I would need a full unit. The initial question as to "why" did the batteries swell, is I did NOT want to put the unit back on line if it was overcharging, and they was a risk of damage, fire, etc.  Looks like I need to just get a brand new unit which will come with a new battery. During the life of this unit it has not had a large load on it at all. Thank you for your information.

[Teken]

For the benefit of you and others who would like more information you may review these APC FAQ:

Battery Life: https://www.se.com/us/en/faqs/FA158934/

Service Life: https://www.se.com/us/en/faqs/FAQ000265093/

Let us know what you decide to purchase when all is said and done. Lastly, if my previous replies provided the answer to your query please mark it as a solution to help the next person asking the same.

Rock On . . . 🤟