H
harry
Hi Folks:
We have several of these UPS's and most, if not ALL, of them tend
to fry batteries. Other than that, I don't think these have ever
failed! We get replacements from the exchange 'deal' but the new ones
do the same thing in a few months.
I was poking around and found a fix! There is a IC10 by the
processor. I think pin 1 is the battery voltage into this A>D
converter. I pull this up to +5V with a 100k to pin 19 or 20 and the
charging regulates now about 26~27V. Note you're looking at the
bottom of the chip so the pins are mirrored. The voltage on pin 1
seems to regulate around 4V. There seems to be some positive feedback,
I assume in the firmware, that spreads the range, but this has worked
on two supplies so far..
I seen on the net someplace that someone's APC melted down from
overcharging, belching smoke, fumes and liquid (acid?)! The charge
current itself doesn't seem to be too high, but it doesn't stop at 28V
on the two stock units I've tested. Both of these eventually melted
the plastic top of both batteries and swelled the batteries beyond the
cage, forcing me to bend/dismantle the case. One was a rack-mount
smart-ups. After the third replacement, I started digging.
Of course, if you do this, you forfeit the warranty. You might
even fry yourself if you don't know what NOT to touch. Please leave
this to the skilled. No warranties...
Take Care! These are great supplies. I hope this makes them better..
Harry
We have several of these UPS's and most, if not ALL, of them tend
to fry batteries. Other than that, I don't think these have ever
failed! We get replacements from the exchange 'deal' but the new ones
do the same thing in a few months.
I was poking around and found a fix! There is a IC10 by the
processor. I think pin 1 is the battery voltage into this A>D
converter. I pull this up to +5V with a 100k to pin 19 or 20 and the
charging regulates now about 26~27V. Note you're looking at the
bottom of the chip so the pins are mirrored. The voltage on pin 1
seems to regulate around 4V. There seems to be some positive feedback,
I assume in the firmware, that spreads the range, but this has worked
on two supplies so far..
I seen on the net someplace that someone's APC melted down from
overcharging, belching smoke, fumes and liquid (acid?)! The charge
current itself doesn't seem to be too high, but it doesn't stop at 28V
on the two stock units I've tested. Both of these eventually melted
the plastic top of both batteries and swelled the batteries beyond the
cage, forcing me to bend/dismantle the case. One was a rack-mount
smart-ups. After the third replacement, I started digging.
Of course, if you do this, you forfeit the warranty. You might
even fry yourself if you don't know what NOT to touch. Please leave
this to the skilled. No warranties...
Take Care! These are great supplies. I hope this makes them better..
Harry
