My car has not been used much for the last couple of weeks. It’s an E220 diesel 2019. The above message has appeared on the dash today and yesterday. I intend to drive it later tonight, couldn’t do so earlier. Strangely on the separate battery and engine menu it looks to be charged ok and the message disappears after a minute or so. Will the battery be ok until I make it to a garage next week ? I have a 2 hour drive tomorrow, do you think it will be ok ? The battery has not been changed up to now.
12V battery yellow warning light
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An amber light generally means that you can drive the car but need to seek assistance. A red warning light means that the car should not not be driven.
The starter battery is only likely to give you grief when trying to start the engine. While driving, the alternator will generate the electricity needed and a weak starter battery will therefore not pose an issue once the engine is running.
The starter battery is only likely to give you grief when trying to start the engine. While driving, the alternator will generate the electricity needed and a weak starter battery will therefore not pose an issue once the engine is running.
MikeInWimbledon
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Your two hour drive today will probably provide the necessary jouice to bring your battery back to a reasonable state of charge.
If you have a car literate frien they could put the car on charge for a few hours to fill the battery completely but, at face value, I’d forget the garage visit unless that yellow light reappears after your long drive.
If you have a car literate frien they could put the car on charge for a few hours to fill the battery completely but, at face value, I’d forget the garage visit unless that yellow light reappears after your long drive.
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While being driven (or rather, when the engine running), the voltage you see is not that of the battery, instead it is the voltage of the electricity generated by the alternator.
And, 14+ Volts generated by the alternator means that the battery itself is currently below 80% charge. Once the battery reaches 80% charge, the Battery Management System (BMS) will reduce the charging voltage to 13+ Volts, in order to slow down the charging and extend battery life.
Have just driven over 100km. Battery is showing 14.2 enroute. Sometimes dropping to 13.8. Didn’t go above those levels. Warning light only comes on after being parked up. No warning now reading 14 after ignition. Need it to last til over weekend including on a ferry. Will use manual key.
As long as the engine is running the voltage will be that of the alternator, as said earlier in this thread.
A top battery would typically be around 12.8 V, as far as I know the battery will never be higher than that voltage, so 13.8-14.2 would be the voltage on your alternator. So, unfortunately this is not a sign of your battery being fully charged.
A top battery would typically be around 12.8 V, as far as I know the battery will never be higher than that voltage, so 13.8-14.2 would be the voltage on your alternator. So, unfortunately this is not a sign of your battery being fully charged.
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If the alternator is outputting 13.8V then this means that the battery has reached a charge level of 80% or more.
