The Troubleshooting and Repair for On-board Charger (OBC) Thread

[Serhiy2192]

So you didn’t change anything, only new battery solved the issue, right?

Actually yes, recently i have charged main battery, but measured up my auxiliary battery in the end of charging cycle and it was 15,5 volts,I pretty sure that it is too much for it. Frankly,the charge was not finished yet,i decided to complete the charge, since the indlicator showed full. After a night, the voltage was 12.9 volts,it's ok.when car is in "ready" it shows 14.2 v,pretty good,like on non-electric cars.How many volts on auxiliary battery during charging by network do you guys have on it?

 

[Piki]

Actually yes, recently i have charged main battery, but measured up my auxiliary battery in the end of charging cycle and it was 15,5 volts,I pretty sure that it is too much for it. Frankly,the charge was not finished yet,i decided to complete the charge, since the indlicator showed full. After a night, the voltage was 12.9 volts,it's ok.when car is in "ready" it shows 14.2 v,pretty good,like on non-electric cars.How many volts on auxiliary battery during charging by network do you guys have on it?

I believe it was 14.7 when I measured. 15.5 really sounds much. Extremely low temperature during charging could explain it probably. But I believe it is the same circuit that charges the 12V battery when the car is in the ready mode and when the HV battery is charging, so it sounds strange. Heck again when charging next time

 

[Serhiy2192]

Ok,got it.i'll check the voltage in the beginning of charging.yesterday i measured the battery after driving it was near 14,3 V.but ignition was OFF
What do you mean extremely low temperature?where?

I believe it was 14.7 when I measured. 15.5 really sounds much. Extremely low temperature during charging could explain it probably. But I believe it is the same circuit that charges the 12V battery when the car is in the ready mode and when the HV battery is charging, so it sounds strange. Heck again when charging next time

 

[kiev]

Environment--ambient air temperature. The charging voltage is raised a bit in cold weather.

But it sounds like your DCDC is putting out too high a voltage.

 

[Serhiy2192]

I am in Florida,here is hot like in hell)
So,yeah,it is pretty weird
I have a 8 amp charger , i will try to charge somewhere

 

[kiev]

If the temperature sensor that is being used to adjust the DCDC output happens to be out of spec--it could be thinking that it's cold out even though it is hot as hell.

Also how sure are you about your volt meter? Calibrated? Expensive or HF?