Battery gone bad ! - Diesel Forum

DAVEHELLO · 08-22-2006, 11:45 AM

I have a 05 PSD. I have one bad battery and I was told by a service tech at ford that I should replace both together. I am leaning toward just replacing the bad one. Which would you do I have no Idea how important it is to replace them both at the same time. He also said that they should have the same cranking amps as the original. Is this important also? Do both batteries have to also have the same cranking amps as each other?

Thanks in advance for any help here.

I am out of warrantee with 42k on my rig.
Dave

corvair · 08-22-2006, 11:54 AM

Yes! You always replace both batteries with new fresh one`s.
The one good one is already being taken down from the bad one,and the same will happen to the new one sooner if you just change one out.

DieselDocFX4 · 08-22-2006, 12:09 PM

I don't understand why you already have bad batteries. Yes you should change both. Get a good battery with high cold cranking amps. Yes it's going to be exspensive but your batteries should last you a couple 3-4 years. I would go with an optima if I was you, great batteries but spendy.

TimsDiesel · 08-22-2006, 12:47 PM

05 with a bad battery? It could happen - seems odd though. I'd get your elec system checked out to be safe. If you dump some bucks on TWO new batteries only to have those go bad you'll be an unhappy camper. Of course check the cables make sure they're tight, corrosion free, etc.

And YES - ALWAYS replace both batteries at the same time.

pajuis · 08-22-2006, 08:50 PM

Yes, both batteries have the same cranking amps. They are group 65 and should always be replaced in pairs.

leros · 08-22-2006, 09:14 PM

Costco sells Optima batteries, probably lower priced than anywhere else.

DAVEHELLO · 08-24-2006, 11:09 AM

Thanks for the input. I went out a bought two new batteries and all seems good now.

Thanks again
Dave

DieselDocFX4 · 08-24-2006, 02:14 PM

I agree with timsdiesel I think you should have the eletrical system check just for the hell of it. You can go to Auto Zone and they will do it for free. But if your batteries go bad again you should have a warrant on them anyways.

short_stuff · 08-24-2006, 04:02 PM

[ QUOTE ]
But if your batteries go bad again you should have a warrant on them anyways.

[/ QUOTE ] That's true for any batteries except the oem batteries. I was told by the dealer on both of my new Ford trucks that the batteries (even brand spaninkg new) are only warrantied as long as it takes to drive the new truck off the lot. If they go bad after that, you are on your own. And I had a year-old Ford F-150 in 1988 that had the battery go dead with no warning, and Ford would only offer to sell me a new battery at twice the price of the autoparts houses. So, buyer beware! Same thing with tires. Which is why I go out and buy a road hazard warranty from my favorite tire store after I buy a new vehicle, for the piece of mind that if the tire goes bad, you're covered.

sickofford · 08-24-2006, 04:21 PM

I know you should replace in pairs, but my 06 with 3700 miles wouldn't start the other day. They towed it the ford dealer where they checked the batteries. One said recharge and check and the other showed a dead cell. The battery they put in was 825cca where the original was 775cc. I asked them to replace both batteries and they said that Ford would not pay unless it showed "bad" and it wouldn't hurt to run two different ccas. Only time will tell.

short_stuff · 08-24-2006, 04:42 PM

I would've preferred both being the same cca, but I guess if they went up on the new one, that's better than nothing. Did they charge you for it?

devwayne · 08-25-2006, 02:38 AM

To hopefully answer your question. Batteries, from the ones in your truck to the ones on my RC10, have an internal resistance. This can be calculated by the voltage present when, a very, very large resistor of known fixed value, is placed momentarily across the leads with the current measured. With these values the internal resistance can be calculated. Essentially the same test at the auto parts store, without the calculation. As the battery goes bad it's internal resistance usually increases, decreasing it's ability to deliver current, and take a charge. Your batteries are in parallel, so if one is bad, the good one will be left to handle most of the current delivery. In an ideal world, you would have both with same internal resistance, or matched cells. Just test both with a known good tester and should be good!! [img]/ubbthreads/images/graemlins/wink.gif[/img]

function12 · 08-26-2006, 11:58 PM

It should be covered under the 3/36.

jimmy · 08-27-2006, 12:03 AM

batteries are covered under the 3/36 but pro-rated after 1/12 if the policy is the same as it was on 2004's.

MarkOomkes · 08-28-2006, 03:11 PM

I had one go bad on my '04, dealer said the same thing, that Ford will only replace if it shows bad. Argued with them, didn't get anywhere, had them replace the bad one, took it back and installed 2 new ones myself. Stupid morons.

And the dealer who told you that it isn't under warranty is hosing you.