Battery dying question

[farmerjoe]

Forgive the rudimentary battery question, but electrical systems are not my forte.

Left the lights on a few weeks ago and came back to a dead battery. Jumped it and all seemed ok until I got back from a week long trip and the car was dead again. Now every time I start it after 12+ hours it struggles to start. Once on it shows 14V on the dash gauge.

Clearly the battery is weak, but is it dying, or is the car just not giving it enough of a charge? Want to be sure I check conventional wisdom before dropping $ on a new battery.

 

[camino70]

How old is it? Have you checked the electrolyte level?

I'd pull it and place it in a charger for a day or two.

 

[LandCruiserPhil]

Most discount auto parts store will load test your battery for free.

 

[flintknapper]

Sounds like a battery that will take, but not 'hold' charge. You can check your alternator for proper output with a multimeter, but your issue sounds like a dying battery.

The only way to know for sure is to have it load tested. Take it to your local auto parts store (AutoZone, etc) and they will test it for you.

If the battery is badly sulfated...charging it will do little good. And they can't 'accurately' load test a battery that isn't fully charged.

Also, a 'dead' or dying cell will drain the other good cells as they try to equalize (most likely your problem).

 

[farmerjoe]

Thanks All - very helpful. I did pull the battery and the service record for my car which I bought last year. Battery was replaced in April 2012 and is OEM so says on it it has a 7 year warranty. If the trickle charge fails I'll take it to Lexus and hope they honor the warranty.

 

[gatormark91]

Don't bother with the pro-rate on a 7 year battery at the end of 7 years. Not worth the trouble. Just go get an Interstate or and Odyssey and call it done. You know you truck will start when you need it.

 

[Spike555]

Your battery was at the end of it's life, the running it dead finished it off. 7yrs is a great run for a car battery, 4yrs is the expected life span.
I agree with not worrying about the prorated warranty, unless it is full replacement at no cost, they're going to give you about $6 towards the purchase of a new one.
Costco sells Interstate branded batteries, 4yrs no questions asked free replacement.
The battery for my truck was $80.

 

[paflytyer]

Once on it shows 14V on the dash gauge..

Once the truck is running, you're reading alternator output, not battery voltage.

 

[farmerjoe]

Ah - ok. I was skeptical about the warranty message and in fact the service record for it's replacement had a 50/50 split comment; now I understand why.

I'll take the Costco advice and head over there today.