Hello! Just need everyones help. I have a '76 F250, 4WD, 4 spd. I have now gone through three batteries in the last year and a half with a new fourth sitting in the trunk of my Mustang ready to go into the truck. The first one worked fine, until it started to not be able to start the truck. It failed the load test and I got a replacement. New battery started and ran the truck great for a while and did the same thing. I took it in and they just replaced it no questions asked. That did the same pattern, and I just took it in and it failed the load test and it was replaced as well. So now I'm on the fourth and I bet it starts fine when I put it in. I'm going to check the alternator again, but what is happening that I'm killing these batteries? I want to know so this fourth one lasts. Plus, I need the truck to start with no problems when the snow flies. Any help would be great!

Nate

 

Couple possibilities:
1) Overcharging - check voltage at battery with engine at high idle.
2) Starter bad - use clamp-on meter to check starter draw.
3) Mounting - excess vibration -

Other than that, you are extremely unlucky....bad battery karma?

 

Definitely do this. It should not be much over 14 volts.

 

Full battery charge voltage should be 13.8 to 14.2 volts.

 

So over the weekend, I put the battery in the truck and I drove it for a while on Saturday. I left the truck running at high idle and checked the voltage at the battery. Dead on 14 volts. I also tested it at regular idle (around 900 rpms) and it is charging at 14 volts then too. Is that a problem? It seems as though the battery is being charged correctly then. Any other ideas?


Nate

 

Other than what alchymist mentioned heat will cook a battery.

 

Are you buying those yellow batteries from WalMart?

I'm on my fourth one of those in my 97 in two years....

Steve

 

The voltage looks good. I don't why it would be eating batteries.

 

Hmm...ok. The batteries have all been Die Hard Gold from sears. I'll just keep driving it and see if it does it again. I'll probably also keep checking the voltage randomly to see if its over charging this winter. I'll keep everyone posted. Thanks for all of your help!


Nate

 

Can the truck be jump started when the battery is dead?

If yes, measure the battery voltage while running, is it still 14V? If it's not 14V, you may have a battery sense line (the A line?) back to the voltage regulator that is resistive.

When the battery is pronounced dead is it after the truck has been sitting for several days without starting, or does it not start again immediately after it has been running?