Found the problem why my 48V 120Ah open lead acid pack wasn't charged properly. Open LA semi traction batteries need 2,65V per cell for the last part of the charge. First step constant current up to 2,45V, then next step max 3,5A to the 2,65V, last step float charge at reduced voltage.
So with the KIPOINT 48V20A charger stopping at 59V the batteries were never fully charged, and they sulphated! The KIPOINT charger is not a real automatic 3 point charger. After reaching the 59V it went directly into float mode. After shifting a zener diode (instructed by the factory) the top voltage could be adjusted to 53,6V BUT: depending of the float point adjusting potmeter it then either 1) went on charging with constant 53,6V at about 10Amps!!! without stopping, or 2) went directly into float charge mode.
Analysing the circuitry it turned out the device is more a power supply than an automatic charger. Only regulating IC is an OpAmp. The other 2 IC's are switch mode controllers.
The KIPOINT charger is maybe OK for SLA type batteries, where the voltage may suffice, but I found no real 2. charging step in the device.
No comments:
Post a Comment