APC UPS BV800i-MSX Battery Swelling

[zandroquerioso]

Good day.

I am Zandro, a foreign engineer currently working here Djibouti Africa.

I want to ask for some inputs about our APC UPS that has a case of swollen batteries.

I have about 100pieces of UPS and 68 of those has swollen batteries.

What could be the possible cause of this battery swelling?

Could it be overcharging? If so, how to stop it from being overcharged since it is plugged 24/7 to its socket outlet.

Thank you very much in advance.

Zandro

[Teken]

The service life of the battery cartridge is rated for 3-5 years based on usage, temperature, and environmental conditions.

All of the batteries have a production date so provide a sample of some here for review along with the bulging cells.

Given the above if the temperatures are high and the cells are old they will begin to deform. As when the cells begin to sulphate or short the input voltage from the charging circuit will heat up the cells.

If the cells begin to heat up they will boil the case and than begin to deform and you may hear a low hissing noise (venting).

The hardware comes with a two year warranty so any that are still covered should be submitted for RMA. Any that are not in warranty you’ll need to replace the cells with the correct 7.5 amp hour rating.

[zandroquerioso]

Hi and thank you for the inputs.

Below is the photo of one of the batteries that was swollen. If my understanding is right, this battery must have been produced on July 3, 2022 or March 7, 2022.

Unfortunately, the local supplier of these batteries is not supportive and simply said that it was due to overcharging. I even shared some snapshots from SE website that the UPS batteries are really meant to be charged all the time so that it can serve its purpose when power outage comes.

About battery manufacturing, what could be the ideal production date before being sold to the market?

Thanks in advance.

[zandroquerioso]

Follow-up question on this, i am sorry.

Based on the catalog for this model, input voltage is below:

But the actual unit is different (220~240V), refer to below photo please:

The voltage here is a bit high and ranging from 240~245V everyday.

But if the UPS can hold inputs between 170~280 v and regulate it have an output of about 230V, then it should not be a problem.

Please enlighten me about this.

Thanks

[Teken]

The first number (179 ~ 280 VAC) indicates the maximum (input voltage) or operating range the system can sustain.

The second number (220~240 VAC) simply indicates the input voltage for the region it’s designed for such as Africa, Asia, Europe, Middle East that may use such (single split phase) AC line voltage. 

As you stated correctly the system will regulate the output to a safer voltage when the input is very high / low. 👍

This specific system was produced on 2022, 17th week. You may go to the APC website and enter this serial number to see if it’s still under warranty.

Keeping in mind your purchase receipt will supersede any production serial number! ☝️

Meaning if the unit was just sitting on the shelf for months / years and you bought it just today as an example. The warranty starts from the (purchase) date on the receipt.

So it’s important to call in to talk to a person to update any and all hardware that may be covered. 👍

[Teken]

Just to be clear the battery in the photo is (NOT) the original APC battery that came with the system?!?

This is important to know either way. As battery quality varies quite a lot between first tier and third tier brands. 

Regardless, every UPS has a minimum of two stages of input voltage. The first stage is charging / equalizing which elevates the input nominal voltage above 12 VDC (14.4 ~ 15) to recharge a depleted or low voltage cell.

Once the cell is fully charged the system will go into a float / maintain state. Where it will hold the voltage at lower and defined level of 13.5 ~ 13.8 VDC per cell. 

If you have a multi meter you can confirm all the above at the battery terminals while it’s connected to the UPS. 

If the system is operating as expected the above values will be seen for both charging and float. If they are higher than what I stated that would confirm the battery vendors suggestion of over charging.

If both voltages are correct the most likely scenario is low quality cells to environmental conditions such as heat.

The system should never be placed in direct sunlight or next to anything that generates heat. As elevated temperatures are one of the major factors to a shorter service life.

An increase of 8’C above the recommended operating range will cut the service life of any battery in half. ☹️

https://www.apc.com/ca/en/faqs/FA158934/

[zandroquerioso]

thank you for these. the voltage specifications became clear to me. However, it leads me to something else about the output voltage.

In my understanding, when the UPS is plugged in to a wall outlet as long as it is within input range (170~280V) then it should still regulate or maintain its output voltage to a safe level, say between 220~240V max.

But from my observation, when the UPS is plugged in from the wall outlet, the output voltage is above 240V (about 242 to 243V). still above the voltage regulated output.

And if i try to unplug it from the wall outlet, then the output voltage becomes regulated to about 238V.

Could it be that the built-in AVR is broken? And could it be the reason why the batteries are being swollen?

Please refer to photos below:

[zandroquerioso]

thank you for this. It makes a lot of sense to me now. I will do measurements as suggested. I will keep you updated about this. having an almost 100pieces of UPS swollen batteries is no joke for a government project like this that has not a lot of funds to replace. Cheers!

[zandroquerioso]

sorry, i forgot to answer your question about the battery that came with the UPS unit.

the batteries that came with our ups is not APC brand. It was Leoch brand.

[Teken]

There are four types of UPS topology but only three are massed produced due to costs.

Your specific model UPS uses Line Interactive and produces a Stepped Approximate Sine Wave (PWM).

The power supplied by the utility is Pure Sine Wave. 

The specifications for this model is not very high as such the output voltage is not highly regulated. Keeping in mind the values you see on AC vs On Battery are very good for such a cheap model. 👍

So the AVR is operating just fine in this regard. Also keep in mind all electrical hardware is designed to operate in upper and lower regions typically at least 5-15% in both extremes without issues. 

Lastly, the charging circuit is not related to the AVR.

You’ll need to measure with a quality multi meter to see what the charging / float voltage are in a few samples to determine if any of the units are operating outside the expected range.

[zandroquerioso]

Noted. I will do that and take few measurements.

Thank you.

[Teken]

To be clear when the unit was opened (sealed box) for the very first time the cell you showed were inside?!?

I ask because APC uses several different battery vendors for different markets.

In North America the vast majority of the higher end systems use CSB batteries which are sometimes covered with the APC Logo.

Other times there are no stickers from APC. 🤦‍♂️

Regardless, if the sealed unit came with these specific branded cells this is one less thing to worry about. 👍

The Leoch / Long branded cells are used in all the lower end models. Especially outside of North America due to costs saving and lower durability and overall performance. 

[zandroquerioso]

The battery i posted are the exact same battery coming with the UPS when it was opened.

Thanks