Hello New to here need help I have a 89 Deville twice since getting it 6 months ago with in an hour of driving the battery was nearly dead but after recharge no problem checked the battery and alternator voltage after and numbers are fine any idea what might be happening not a great problem but would be nice to know it's going to start Thanks ahead of time for any advise

Deville Sid

Battery and alternator need to be "load tested" if they pass, then the car needs to be checked for a battery draw. Putting a load on the battery will confirm the strength of the battery. Simple voltage numbers dont give you all the proper answers to make a decision. Putting a load on the alternator will allow it to go to a full ampereage output. If the alt is rated at 110 amps then the test should show virtually 110 amp output for example. Have you checked battery cables for being clean and tight? have you checked the belt tension on the alternator?

Yes my next step was to get load test, but seems weird that i have problem 6 months apart Checked cables, belt connections ect thanks for your reply

I agree get a load test but I always change them both when one dies most of the time the die close to each other. A alt charging a battery with a bad cell kills the alt. A bad alt will leave you stuck . Good luck