I have the following 12V car battery: Varta Silver Dynamic AGM 595901085 (12V/95Ah/850A), and the following car: Jaguar S-Type 2.7D.

In the technical cars manual it says this:

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So in cold winter mornings, when I initially start the car, the alternator is charging the battery with with 15.5V.

Is this safe for the battery?

Varta recommends charging it with up to 14.8V (according to what I found on their website).

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I have a Jag Xtype, 2.2D and it has the same charge controlling system.

Don’t worry about it - mine does get to 15.3V certain times in winter and rapidly comes down to 14.8V.

Now as the temperatures are rising it is staying below 14.7 - actually between 14.0 and 14.7V as it sorts itself out.

The charge controller will also reduce the alternator demand when full engine power is demanded so it controls the situation very finely.

As long as it is working properly and the connections are tight with a good battery then all will be well. If the battery is poor then that can cause many spurious faults to appear - none of which are real - our machines like a good battery.

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