Noticed over the past three weeks the truck (2005 F250 PS) has been cranking slower and slower on start. This afternoon after sitting for 4 days in the airport parking lot it cranked very slow - the engine caught, but just barely. Charging voltage is good (ScanGuage II). I stopped at an AutoZone and had them do a battery load test. Primary (driver side battery) was fine, 850 cranking amps. Aux battery (passenger side) was dead. Stopped at the dealership where they confirmed the dead aux battery and agreed to a warrenty replacement. When I got the truck back, the new battery was in the primary position! I hope they moved the battery that was there to the aux position vs. replacing the wrong one. I will go by AutoZone tomorrow and have them check the aux again. It does crank much better though.

PS: While waiting I did check out the new 2008s on the lot. About a dozen, an equal number of 2007 still on the lot as well. Yeh, the headlights do look better first-hand than in the pictures. But still not thrilled. Most were Lariats, some XLTs. All were diesels. Exhaust system on them is massive! One of the sales guys did get curious when he saw me crawling around under one of the trucks.

Steve

 

swengle,

Now for the bad news. With a dual battery setup, such as the one in the PSD, when one battery goes bad you need to change both batteries at the same time, the bad battery shortened the life of the battery that is still testing good. It will be a short matter of time before the old battery goes bad. If you don't replace both batteries at the same time, the old battery will go bad and damage the new battery and by changing one battery at a time it will be a vicious cycle.

Since the batteries are hooked up in parallel, and one bad cell will sap the energy of all other cells in the system and effect the charging of all other cells in the system.

Hope this helps

 

When you change batteries you need to check your door ajar switches. They are notorious for killing batteries from having the dome light on during the day.

 

Before I read blackhat's post I would have said the putting the new one in the primary spot and moving the old one over to the other side sounds logical. Put the newer bat in the primary position.

 

Also need to make sure when batteries are changed that they are same size and type IE. type 32 850cca.

 

Yep, the new battery will very soon be no better than the used battery that was left in the truck. You should always replace both batteries, if one of the old ones still holds a charge put it to use somewhere else.
I don't know what or why some are refering to these batteries as "primary" and "auxillary", to my knowledge they are simply hooked up in parallel so as to double the reserve capacity and the cold cranking amps.

 

&%%@$%* dealership! I asked the service rep "If one goes bad, does it take out the other?" and he said no. Plus the one they put in is 750 CCA vs. the original 850. Further reduces my impression of this dealership.

Right now I am considering Interstate Mega-Tron Plus "MTP-65" (875 CCA) or Wal-Mart EverStart "MAXX-65N" (850 CCA). Will replace both batteries leaving me with 1, may 2, batteries for other uses. Have not looked into pricing yet (North Texas).

Thought about Optima or Odyssey but a lot more dollars plus neither appear to have a drop in fit (i.e. size 65, which is apparently what the truck takes).

Thanks for the feed back all!

Steve

 

On a diesel truck (at least Ford Super Duty's 6.0L) the batteries are hooked in parellel, so there is no such thing as "primary and secondary" batteries. The truck utilizes both of them for glow plug heating and all electrical needs.

Does this mean that a single alternator charges one battery then the other... heck no.... it charges them both at the same time!!!

Your dealership is full of hooey and I believe that the manual may even state such??? I would be more concerned with different CCA ratings. Check your manual and make sure you have equal to what it states or greater... and yes, both batteries should be the same.

 

The "primary" battery is considered the passenger side due to the fact that it is directly connected to the alternator input and both starter and glow plug output. The "secondary" battery is considered the driver's side since its only connection with the rest of the system is delivered through the primary. The primary is subject to higher load stresses and voltage fluctuations than the first.

 

Good post at the right time. My truck has 59,400 km last week when I took it to get checked out before it goes off warranty. I had develoved a slight drone and I complained about the buzz flash. They put on a new Turbo pedestal(?) and reflased it. A couple of days later it cranked slower and slower. Mechanic thought it was a bad fuel pump. Checked battery and found drivers side dead. Replaced under warranty. 2005 F350 CC SD LB lariat. Anybody in same mileage would not hurt to get those batt. checked before it cost you $100+ to get one replaced. BTW the drone is gone.

 

The truck now has two new Wal-Mart EverStart "MAXX-65S" (850 CCA) batteries. They are made by Johnson Controls (whom also makes the Optima battery). Nice and fresh, manufactured this very month. They dropped right in, took all of half an hour. It starts very smartly.

The two batteries I pulled (one obviously new), I went by AutoZone and had them test. Sure enough, the passenger side battery was dead - the dealership bozos (see yesterday's post) had replaced the wrong one. I'm half way through drafting a letter to the North Central Ford (Richardson, TX) Service Manager informing him that his service staff is incompetent, incapable of even simple procedures. They even mess up on oil changes (overfilled crank case, twice now) and fluid replenishes (power steering reservoir way overfilled).

Thanks for all the feedback folks. It really helped!

Steve

 

what was the cost of the 2 ever start batts from walmart? did they install them for free?

 

Batteries were $62.28 each. A $3 "Texas Battery Fee" and a core charge of $9 were also charged (per battery). I did not inquire as to install, even if they offered it for free, I still would have done it myself.

Steve

 

I paid $72 a piece for Napa Gold batteries. They have a better warranty than the Motorcraft batteries and were $30 less a piece!

 

When you replace the batteries does the computer have to relearn everthing again or is there a way to keep one hooked up while they are being replaced.

Randy