RS-800 any reports on overheat or fire?

[ctaddey_apc]

ok first of all I have a little story:
I have a 3-year old rs800, and last day before I went on a holiday trip, I got the replace battery led on after power cycling the ups.
So I left the ups powered off but still connected (all leds were off).
I returned after 8 days, and when I was going to turn it on again I felt a lot of heat coming out the UPS, so I unplugged all cables and opened the battery cover, but was unable to take out the battery due to it being burning-hot to the touch. I allowed it to cool down a while, 30 minutes later and still was very warm, plus the battery pack were somewhat jammed inside the ups.
Finally it came out, but the batteries have very noticeable 'lumps' on them.

Now I'm a little worried about this product's risking a fire in my home. I think that if I took 2 weeks instead of 1 the baterries could have exploded or set the desk it was on on fire.
If someone with more experience with this model/brand want to give his oppinion...
why the overheat if the unit was off? is this a firmware failure or it is ok for the battery to keep charging even if the ups is off?
Even if it was meant to keep charging, doesnt apc ups have some security measures to keep this from happening? (like charge timers, or even temp sensor like some notebooks batteries) I tough this was a quality product.
should I turn the unit to apc for repairs?

Best regards
Christian.

[ctaddey_apc · Accepted solution]

ok first of all I have a little story:
I have a 3-year old rs800, and last day before I went on a holiday trip, I got the replace battery led on after power cycling the ups.
So I left the ups powered off but still connected (all leds were off).
I returned after 8 days, and when I was going to turn it on again I felt a lot of heat coming out the UPS, so I unplugged all cables and opened the battery cover, but was unable to take out the battery due to it being burning-hot to the touch. I allowed it to cool down a while, 30 minutes later and still was very warm, plus the battery pack were somewhat jammed inside the ups.
Finally it came out, but the batteries have very noticeable 'lumps' on them.

Now I'm a little worried about this product's risking a fire in my home. I think that if I took 2 weeks instead of 1 the baterries could have exploded or set the desk it was on on fire.
If someone with more experience with this model/brand want to give his oppinion...
why the overheat if the unit was off? is this a firmware failure or it is ok for the battery to keep charging even if the ups is off?
Even if it was meant to keep charging, doesnt apc ups have some security measures to keep this from happening? (like charge timers, or even temp sensor like some notebooks batteries) I tough this was a quality product.
should I turn the unit to apc for repairs?

Best regards
Christian.