Smart UPS 1500 (DLA1500I) - Batteries overcharged and Venting

[Anonymous user]

I would appreciate some advice before I purchase new batteries for this unit.

For several weeks I have had the red battery warning light and beep for 1 minute every 5 hours indicating battery replacement. As this is non critical application and I have not had spare funds I have ignored the warning until I could afford to replace the batteries. However events have progressed which has now forced me to do something.

After returning one evening I opened my workshop door the UPS was beeping constantly and the room was hot and full of the smell of acid. When I touched the UPS it was very hot. I shut everything down and removed the UPS to the garage to cool down.

I have now had chance to open the case and inspect the batteries both have which have swollen and stuck together.

My question therefore is. Do you think the UPS control circuits have been damaged as a result of this overcharging as I assume this is what has happened or is the charging circuit robust enough to cope with this for several hours?

Is there a way to run some tests to see if the system is still operational without the batteries or temporarily reconnecting the old batteries?

I really don't want to spend circa £90 on two replacement batteries only to find the UPS itself has been damaged. The unit itself is probably too big for the task and I would perhaps try and purchase a smaller replacement and put the £90 towards an new UPS.

I am aware that I am asking people to Crystal Ball Gaze and the stock answer is to send it to a service department for testing, but perhaps people on this forum have experienced similar overcharging with no long term damage to the UPS and can give real world experience.

Many thanks

John

[BillP]

Hi John,

It's hard to say whether or not a failed and run-away charging circuit destroyed the batteries or a failure in one or both batteries was the cause of the overheating and venting.

In theory, if you had a digital volt meter you could check the battery voltage and get a rough idea of whether or not the charging circuit was working.  The two 12volt batteries when connected in series should be floating at about +13.6 VDC each, give or take, or about +27.2 for the pair.  Any higher than that and the charger would cook the batteries over time.

How old were the batteries that were installed?  If not too old, say less than three years, I'd bet the battery charging circuit took off on you and cooked the batteries.  If the UPS is older than five or six years, I'd invest in a new, appropriately sized, model because the battery management circuitry has improved considerably.

Good luck!

Joe

[BillP · Accepted solution]

Hello John, I apologize that you had this experience with the UPS. Do you happen to know the model and serial number? Do you know how long ago the unit was purchased and how long ago the battery was replaced?

Either way, the charging circuits turn off when the battery reaches a certain temperature to avoid thermal runaway. What happens if the battery is repeatedly charged and heated when reaching end of life, it starts heating up quicker. It gets to a point where the battery starts heating up too quick, and the battery enters thermal runaway before the charging circuit turns off. When this happens, the battery heats up and swells. We have seen this before when a replace battery is ignored for a long time. I completely understand that budget can be time sensitive and again I am sorry that this happened.

When we see a battery swell, we always recommend replacing the unit. With our trade-ups program, often the cost of the replacement unit is not much more than the cost of a new battery. Along with a new unit and battery, you also get the factory warranty and option to extend, which can give you a longer time before you have to worry at all about the UPS.

Thanks,

Shanon