battery life %

[White340]

Hi,

For those who have BimmerLink I’m curious to know what your battery health percentage is. Mine has hovered around 83-87% but I didn’t drive it for 5 weeks and it got down to 9%. I drove it to recharge and it’s now at 81%. I will get a tender for the future but still curious what other people’s levels are. My car is just under 5y old and has 28k on it.

Thanks

[ron_s55]

I think you're looking at SoC, State of Charge, which is basically the voltage. Like 100% would mean it's fully charged. It's not exactly the health of the battery.

[White340]

Originally Posted by ron_s55

I think you're looking at SoC, State of Charge, which is basically the voltage. Like 100% would mean it's fully charged. It's not exactly the health of the battery.

Thanks. The highest I’ve seen it is around 85%. This look normal?

[gerri]

Originally Posted by White340

Thanks. The highest I’ve seen it is around 85%. This look normal?

Maybe this taken from TIS explains it.

Vehicle with intelligent alternator control (IGR)
Unlike the normal control of the battery charge, the intelligent alternator control prevents 100 % charging of the battery. The battery charge goes to the range of 75 - 85 % of the maximum possible charge. This means that the battery remains "chargeable" to permit energy recovery in the vehicle overrun phase.
The power management co-ordinates the various requirements for the vehicle voltage:
- Battery: Nominal voltage depends on the temperature of the battery. Minimum and maximum voltage to permanently protect against excessive voltage and discharge with poor state of charge. In cycles, the intelligent alternator control is suppressed; this permits 100 % battery charge to achieve full battery capacity for a sustained period (regeneration).
- Components of the vehicle electrical system and functions (e.g. exterior lights or Dynamic Stability Control): minimum or maximum necessary voltage. These limit values must not be undershot or exceeded, as otherwise there can be functional limitations or function failures.
- Operating condition of the IGR: Energy recovery in the overrun phases, partial alternator relief (no battery discharge permitted) or alternator relief (return of the energy from the battery into the vehicle electrical system).