Batteries heated up and melted inside the APC unit

[BillP]

apc 700 smartups

So we start smelling something on the first floor and finally trace it down to the APC when I touch it and it's burning up.
Plastic was soft as could be they were so hot when I pulled them out.
Even had the usual inline fuse between them. Batteries aren't that old. What caused this and why is there no failsafe?

http://img404.imageshack.us/img404/6283/apcbatter.jpg

[BillP]

How old are the batteries, exactly? If they are original to the UPS, they must be at least 3-5 years old, since the 700 model has been discontinued for quite some time. If they're newer, did you replace them with APC batteries? The model & serial number for both the batteries and the UPS would help - there should be a white sticker with barcodes on the UPS (usually on the back) and somewhere on the batteries as well.

Old batteries will experience this issue if left unattended for some time. The unit should have given an alarm about the batteries - either a flashing or solid light on the replace battery indicator on the front display - long before they reached this state. Charging produces heat, but dead batteries don't hold much charge. It becomes a cycle of increasing heat, which causes the gases inside the battery to expand and, eventually, leak out of the battery casing. That's the smell you detected, and that's why the casing is misshapen.

See [kbase 564|http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=564] for the MSDS sheets for APC batteries.

[BillP]

They are not old and not originals.

We have about 20+ APC units and sure batteries die and the thing beeps and I replace them.
No beeping here.
From reading online

"In fail short situation the low battery will absorb the energy and the
voltage will not raise and the batts will slowly heat up. It should be
detected."

Sounds like what happened and the APC unit has no temp sensor so it isn't smart enough to know something is wrong.
Makes me worry about the other 20 units. I mean this happened here on friday. A few more hours and we'd have been gone for the weekend. What would have happened in that length of time.

Message was edited by: Aaron91RS

[BillP]

I'm not sure where you're reading or how it relates to APC, but the battery alarms are more related to the capacity and self-test results than temperature. However, the Smart-UPS units do have temperature sensors and alarms associated with exceeded thresholds - assuming you are using the free software or a network card. Are you?

The event is described as "UPS Internal Temperature Threshold Exceeded" and it has a logging, notification, email, command file and shutdown option for this event. It's smart enough to recognize it, but unless you provide a means of notifying someone of the issue, it can't do much.

You haven't mentioned the model & serial numbers of the unit or its batteries. If they are 700va units, they are definitely more than a few years old. If they aren't the original batteries, did you replace them with APC batteries or other brands? It's difficult to tell from the picture you provided since I cannot see the APC logo on the batteries.

It's difficult to offer explanations of what happened with an incomplete version of the story.

[Erasmus_apc · Accepted solution]

Assumed answered due to lack of customer update/response.