APC Smart UPS 450 - hot case- what is wrong 1

[DEBWEST]

I have the subject UPS that has been working fine for many years. I have replaced the batteries several times and have never had a problem. Today the case is very hot and it smells like something is burning. The powerchute software says all is well and the test button test also says there is nothing wrong. Any ideas?
Thankyou.

 

[MacyH]

This is usually caused by a failed battery, it has a shorted cell. It will swell and possibly melt.

What to do? First, replace all the gel cell batteries in the UPS. This will usually return the unit to normal operation.

In the event the charging controller is defective or out of adjustment, it will overcharge the battery and eventually it will fail in a simlar manner.

The general rule of thumb is: if a new battery lasts less than a year or two, it's probably best to replace the UPS. On larger UPS it may be worth having a qualitified repair technician to check the unit out. Smaller UPS systems are generally not worth the repair costs.