Truck Battery Help

[EventsInTheChamber]

I went and took a truck I've been looking at for a test drive the other day, went to start it and the battery was dead (previous test drive left the lights on) so the dealer boosted it for me, worked fine.
My question is would the battery have been affected in any way or would it have charged back up?. I'm asking because I deceided to purchase the vehicle and if there is any chance the batt could be screwed I'm going to get them to throw a new one in.

Your opinions welcome!

 

[AKSNOWRIDER]

I went and took a truck I've been looking at for a test drive the other day, went to start it and the battery was dead (previous test drive left the lights on) so the dealer boosted it for me, worked fine.
My question is would the battery have been affected in any way or would it have charged back up?. I'm asking because I deceided to purchase the vehicle and if there is any chance the batt could be screwed I'm going to get them to throw a new one in.

Your opinions welcome!

if it went completely dead..it hurt the battery a little bit..an easy test..pull the coil wire and crank for ten seconds..let rest 2 minutes and repeat..then after 2 minute rest rehook up the coil wire..if it restarts it is ok..if it really slows on the crank battery is going bad, works as a poor mans load test ...also can test alternator by pulling negative batt cable loose while truck is idleing..if it dies truck is not charging good....

 

[jimmy buffet]

depends on how old the batt is. could of hurt it but not likely. but hey, tell them to throw a new one in anyways. should be fine though.

 

[ruffryder]

pulling negative batt cable loose while truck is idleing..if it dies truck is not charging good....

That is not a test to use for fuel injected, heavily electronic vehicles. I do not think they provide enough power at idle.

Did it ruin the battery, probably not, but it did take some life span away. Vehicle batteries are not meant to be completely drained as life span deteriorates. Have them through in another one.

 

[EventsInTheChamber]

Thanks, I spoke with the dealership and they are happy to throw another in for me!.

 

[EricW]

Not to challenge the integrity of a used car salesman, but, you might want to check that the original problem was actually that the lights were left on prior to your test drive. I see the portable jumpers in action all the time on used car lots. Can't all be lights being left on.

You should do a quick check for an electrical short. Pop the hood, close the doors, turn off anything that could draw power including pulling the under hood light if it has one. Pull the positive battery cable and put a simple 12v test light between the battery post and the cable. If it lights up, it it still drawing power some where. There may be a radio clock or some other device, but if you feel there is no other legitimate drain, then you have a short.

You can also swing by any repair shop and have them do the same test with a muti-tester to see just how many amps its drawing. This will tell you if it is a accessory or not. Good luck. EW