Tag: lead acid battery

APC Back-UPS capacity upgrade (#P11F1)

Was that foreseeable? Not sure, but the design called for it…

Now that my modified APC UPS is running smoothly again (#P11), I still had two pairs of these nice XT60 connectors laying around. And as old, to-be-recycled lead acid batteries from UPSes pile up at work, I took one or two of them with me for testing at my electronic load. Like previous batteries, quite a lot of them are really toast, but some of them are in decent condition. Not as in “like new, ready for another year of service in a commercial fire alarm system”, but still holding a significant fraction of their original capacity and delivering a suitable amount of current. […]


APC Back-UPS external battery mod (#P11)

Good thing I’m a doofus. While tidying up cables after some keystone module action, I also moved the bulky power supply of my monitor. And then I noticed that the only thing that absolutely has to be on the battery backup outlets of my UPS unit was in fact…assigned to the surge-protected ones that fail when mains power is gone. D’oh. After some cable identification in that tight space, I moved the UPS around a bit and I discovered a drop of liquid. A very dubious drop at a place where liquid would have to seep through 4 centimeters of a wooden table, or somehow permeate 1.5mm of solid steel against gravity’s pull. […]