I am using Ubuntu and I have an APC Back-UPS 550 uninterruptible power supply that's worked pretty well for several years.
However, over the last year, it's "bad battery" alarm has routinely started activating, and each time appears to be a false alarm.
A loud persistent piezo buzzer blares while it's status LED flashes between green and red. According to the manual, this means the lead-acid battery is bad and needs to be replaced. However, upon inspecting it, he battery has a full charge and is in perfect condition.
Just to be safe, I bought a new battery, and the problem went away, but then about 6 months later, the bad battery alarm came on again. I know these batteries don't last forever, but they should last for 3-4 years, not just 6 months.
What's causing this, and is there any way to fix it? Is the UPS unit defective? Is there any way I can disassemble it and either fix or deactivate this "alarm". Since the unit otherwise works great, I half suspect this is just APC's way of trying to get me to buy more batteries, which aren't cheap.
Edit: Discovering some docs on APC's website, it says the false alarm buzzer issue can sometimes happen if you overload the unit and connect too many high-wattage appliances to it, even when it's on external power. I can't be sure, but that might have been my problem. The unit seems designed to power a typical desktop pc and maybe a monitor, but I was using it to power two 1U servers, a desktop PC, and a hefty wifi router.
I'll try redistributing some of the load to a second ups and see if that resolves the problem.
