SURT 10000 RM XL inverter fault

[jwalker55_apc]

I woke up to a barrage of alerts from this unit saying "An inverter fault exists", "refused a self-test", and "in bypass in response to an internal hardware fault". I'm pretty sure when I logged into the web card remotely it had a battery charger fault and a battery temperature warning in there too.

After a couple minutes of this, it shut itself off. At about that same time, it triggered our fire suppression system (fm-200 clean agent) and we got a visit from the fire department. There was no evidence of fire that I could tell and thankfully, no equipment is damaged that I'm aware of either. I shut the breaker off to the unit, so I have no idea what LEDs were lit on the front.

What are the odds this was just the batteries? They are due for replacement at about 5 yrs old. I actually have new batteries on hand that I was getting ready to swap in within the next couple weeks. Obviously I'm going to reach out for professional support, but was wondering what others experience was with this, if any.

EDIT: As I spent more time dealing with this early this morning, I'm confident that the issue is not the batteries, as the smell is more of a burnt capacitor smell, rather than a sulfur/hyrdrogen sulfide smell. I pulled all the battery cartridges out and they are completely odorless. I think the unit is toast and it's time to replace. thanks