A week ago, I bought a Powerware 3105 UPS from a local junk shop.
Opening it revealed two bad Rifeking
WL series capacitors (C10 and C11) in the charger circuit. Another Rifeking capacitor of the same series was connected between the battery and common was found.
All three Rifeking capacitors were replaced with low-ESR units.
The battery sulphated because of the two bad capacitors having a lower capacitance, and therefore, lower reactance.
For a 1000uF capacitor, the reactance is 3.2 ohms @ 50Hz.
The capacitance and reactance of the bad units were 36.8uF @ 86.5 ohms, and 27.6uF @ 115 ohms, both at 50Hz.
Opening it revealed two bad Rifeking
WL series capacitors (C10 and C11) in the charger circuit. Another Rifeking capacitor of the same series was connected between the battery and common was found.All three Rifeking capacitors were replaced with low-ESR units.
The battery sulphated because of the two bad capacitors having a lower capacitance, and therefore, lower reactance.
For a 1000uF capacitor, the reactance is 3.2 ohms @ 50Hz.
The capacitance and reactance of the bad units were 36.8uF @ 86.5 ohms, and 27.6uF @ 115 ohms, both at 50Hz.
Attached Files