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Does leaving the old but still in good condition and fully charged battery in the vehicle when fitting a new alternator void the alternator warranty? Do you have to have a new battery to keep the alternator warranty?
2009 jeep Cherokee KK 3.7V6 petrol

Hi there,
The supplier of the alternator should be able to advise on the warranty conditions, but I have never heard of (and would think it very unusual) the requirement to have a new battery fitted if an alternator is replaced.

Certainly the battery state of health should be checked and the battery replaced if required in order for the alternator to do its job effectively.