Battery indicator light on the battery - Diesel Forum

davidsc · 09-29-2009, 06:17 PM

This may be a stupid question, but what does the battery indicator light on the BXT-65-750 stock batteries mean? I just got my truck back from the dealership and the lights that were green when I brought it in are now red. They have had the truck for a while, is this something that will change back to green after I run the truck for a while and they just haven't re-charged? or were the batteries run down so much that they are essentially on their way out now? I can't find any good info on this topic.

rock_doctor · 09-29-2009, 09:19 PM

Most mechanics feel the eyes mean nothing but it is basically telling you the specific gravity of the electrolyte in that particular cell is low or it needs to be charged. Drive the truck around town for a half hour and give them another look. Or (and this is the better choice) swing by your local walmart and have the batteries checked. They need to unhook them and test separately. If you don't like walmart, then choose who ever you like that sells batteries. If one is bad replace both, if one is weak replace both. If this is a 6.0 that is an 05 and newer don't play around with it. Some have hypothesized that bad/weak batteries can take out the $1200 fuel injection control module.

davidsc · 09-30-2009, 09:52 AM

Thanks Rock_doctor, its an 08 6.4L. As I mentioned, I just got it back from the dealership and when I brought it in they were green. They obviously had the hood and door(s) open to work on the vehicle so my concern is that they drained the batteries completely and then charged then. I am now placed in the awkward position of having to argue that they essentially cut the life span of my batteries in half when there is no real "behavioral" problem from the batteries at this current point. Just something that will effect me at the worst time and, as you mentioned, possibly cause a much larger problem down the line. I will get them check as soon as I can.

rock_doctor · 09-30-2009, 05:44 PM

I had a shop work on my 6.2 GM diesel. They cranked the engine so much they actually melted the lead posts on the battery. They didn't care just like your dealer will not care. The normal lifespan on the original batteries is on average 3-4 years. The fact that it is a 6.4 works in your favor, i had assumed it was a 6.0. There is no evidence of computer problems with this truck as there is with the 6.0. I would have them load test them separately, if they produce the listed load you should be ok. Good luck

wingnut60 · 10-01-2009, 05:06 PM

Your Ford has an automatic cutoff that shuts off all lights after about 15 min of non-activity, maybe even less time. And running the batteries low shouldn't "cut the life span in half" altho every discharge cycle is one less that the batts can be run through. As rock doc say, if you are worried about them, have them checked under load.