F-250 dual battery change

Some people have said a 3/4 ton truck is overkill when towing an Airstream trailer, but I am very happy that we chose a 2006 Ford F-250 Super Duty 4×2 Crew Cab diesel truck when we purchased our 2007 23′ Airstream Safari trailer nine years ago, especially every time we travel from near sea level to 5,000 feet elevation over the often windy mountains to our favorite campground in the desert.  It gives us a great sense of confidence, security, and peace of mind under the stars.

DSC_0057 F-250 & Airstream trailer

The truck has been virtually trouble free and only needing the routine scheduled items listed in my service manual, and the routine tire and battery changes.  This truck requires two 12-volt batteries to turn over the diesel engine and my original batteries lasted 5 years before dying.  In 2011, I replaced these batteries with Costco’s Kirkland Signature batteries, 65-850, which had a 100-month limited, prorated warranty.  I was hoping that these batteries would also last 5 years, but a few weeks ago, I noticed that the engine was slow to start.  I first thought this was due to old fuel sitting over the summer (our off-season for camping).  But reality set in when it would not start in a parking lot last week and required AAA to do a jump-start!

I returned to our local Costco and bought two new batteries.  The battery brand, Interstate, has now replaced the Kirkland Signature brand, but both are made by the same company, Johnson Controls.  For the new batteries, Costco now provides a non-prorated, 42-month warranty.  My new Interstate batteries cost $89.99 + battery core charge (deposit) of $15 each.

I returned my Kirkland Signature batteries to Costco and since my $85.99-batteries lasted 50 months, Costco gave me 50% back (credited to my credit card), along with the battery core charges.

Changing my batteries was relatively easy (since I took notes last time and am now documenting them here for future use, but note that the steps below are how I went about changing my batteries and are not intended to tell others how to change their batteries).  As a refresher, I viewed “How to replace dual batteries on a Ford F-series diesel“.*

DSC_0150 F250 6

DSC_0154 Interstate 65-850 battery

Our F-250 diesel truck requires two 65-850 batteries (65 is the group size and 850 is the cold cranking amps (CCA).  On the top of the battery is a sticker indicating the manufacturing date (10/15) and a label to scratch/mark the installation date.

First I assembled my tools: 5/16″ hand wrench and a 8 mm socket with wrench extender. Then (and most importantly), I disconnected the black, negative (ground) cables first from both batteries (the clamp nut is loosened and the clamp is worked back and forth while pulling up).

DSC_0151 Disconnect black:negative cable 1st

Important: only after the black, negative cables are disconnected, did I disconnect the red, positive cables!  Then I unsnapped the street-side battery cover by pushing in the tabs on each lower side while raising the cover off.

DSC_0152 Driver's side battery & cover

A 8-mm socket wrench and extender were then used to remove the bolt and clamp holding the battery in place and the batteries were removed. The battery tray was inspected and cleaned (of dust and sand) and the new batteries placed and secured with the clamps and bolts.  The street-side battery cover was re-secured. The cables were then attached in the reverse order of how they were removed.  The red, positive cables were connected first, followed by the black, negative cables. I was careful not to over-tighten any of the nuts.

So now our Ford truck is a perfect fit and should be good to go (for at least another 4 years), and I guess you could say, “I’m a Ford truck man!“*

HPIM2824 Ford truck man

*This is a link to a YouTube video.


  1. says

    We’ve had a Dodge 2004 with a Cummings Diesel engine which also requires two batteries. But we must have been extraordinarily lucky as ours lasted about seven years. A company in Borrego Springs replaced them and I guess the next seven year span is about to elapse.