When to replace 2002 F150 battery?

Just curious…if it aint broke, do I fix it?

Should I just replace it because it is getting old, or keep going until I have problems?

Most folks just go until they are left stranded in the parking lot at WalMart on a cold night, probably right after their auto center closes. It’s up to you. A six year old OEM battery is well past its life expectency. Granted I’ve seen one that was seven years old, but I think it was a mutant.

Do you carry jumper cables in the truck?

“Hey Mister, can you give me a jump”?

“Sorry, I don’t have any cables”.

“No problem. I do.” You see, then they can’t back out.

Hey thanks…I have a cap, tool box, cables, tow strap, shovel, sand with salt, life jackets, extra sneakers, socks, blanket…so I like to be prepared and occasionally head north where a jump may not be available. I also leave my keys inside, and depend on the combination lock on the door to get in. If the battery is dead, I am outside in the weather, and all of my goodies are useless, until I break a window.

I’ll probably replace it soon.


After about five or six years I start watching for signs. If it starts getting a little slow turning over, I replace it. In the old days when I was young (and poor) I waited until I knew it was bad.

If you are curious, most auto parts stores will check them for free and they are usually honest, if not 100% accurate. It may help make up your mind.

Like people, as a battery ages, things start to go wrong with it. If the battery develops an internal short, it can take the alternator out with it. The alternator would try to charge the battery, and the battery short would cause a high amperage draw on the alternator. It could draw a harmful amount of amperage from the alternator. Soon (a few days, weeks, months), the alternator could fail.

I’m not keen on leaving batteries in until I’m stranded somewhere. If that’s the original battery then it’s had a good life and should be replaced, especially if you’re going into the boondocks.

A load test can be performed to determine just how good that battery is.
It should be placed on a battery charger for at least .5 an hour and a load applied with a carbon pile. The rule of thumb on a load is 3X the normal starter current draw on a warm engine.
Starter current draw is tested and the load applied should be triple that amount.
The load is applied for 15 seconds and at the end of that time the battery should have maintained a minimum 10.2 volts. Under 10 is iffy and around 9 and below is junk.

Some places may perform a test like this free. If you have to pay a shop to do this then it may not be cost effective when weighing the cost of the test against the price of a new battery. Hope that helps.

Thanks for the help all.

My fiance said that she would give me the $79 to buy the napa battery that I saw in consumer reports to essentially get my mind off of thinking about it. I think that I can buy my own battery, and will probably do that tomorrow. Why wait. I wont be keeping the truck for another five years, but the battery could fail when I need it.