Low battery

[Keith Hawdon]

Hi, I have a V60 D5 which repeatedly shows a low battery. The original battery had a bad cell and when charged shows only 12.20V so in this case the car made a good call. I replaced the battery and the problem went away for a few months. Now when the battery is fully charged to 12.8V and the car is left sitting for four or five days it shows low battery when started, upon investigation after four days or so the battery reads 12.5/6v before starting.
I am currently updating the map data and with a charger apply in 6amps to the battery and floating at 12.9v the car is again reporting a low battery.
Can anyone tell me how the car's systems calculate the voltage and what voltage it thinks is healthy?
The charge is connected between the positive post of the battery and the engine block, also where the voltage readings have been taken.

[harveys]

Originally Posted by Keith Hawdon

Hi, I have a V60 D5 which repeatedly shows a low battery. The original battery had a bad cell and when charged shows only 12.20V so in this case the car made a good call. I replaced the battery and the problem went away for a few months. Now when the battery is fully charged to 12.8V and the car is left sitting for four or five days it shows low battery when started, upon investigation after four days or so the battery reads 12.5/6v before starting.
I am currently updating the map data and with a charger apply in 6amps to the battery and floating at 12.9v the car is again reporting a low battery.
Can anyone tell me how the car's systems calculate the voltage and what voltage it thinks is healthy?
The charge is connected between the positive post of the battery and the engine block, also where the voltage readings have been taken.

When the new battery was fitted was the BMS reset ?.
If not the car will be thinking it's a older battery so it could be wrong .

[Clan]

Originally Posted by harveys

When the new battery was fitted was the BMS reset ?.
If not the car will be thinking it's a older battery so it could be wrong .

ithe BMS data is cleared when the terminal is removed .. It will soon build up a few pages of A4 data ...

[glynh]

have you tried the 'reset' thing with pressing buttons? have a search on this section as there are a few threads with what you need to press to reset.