6C 300 AH AGM 6V Batteries

[JLMunsil]

What changes are needed in the battery bay to install the 6C 300 AH Lifeline batteries? I understand they are 3 inches taller than the 4C. Looks like there will be some interference.

[EngineerMike]

JL- I just installed 4 of them (600AH capacity @ 12V) w/the battery's long direction left-right. Two go behind the left hand 1" square tube, two in front of it. Batteries are pulled out to the PS edge of the tray. This leaves space behind, in front, and between the batteries & frame. I tied them in place w/extra large zip ties. I didn't need to change anything.

If you go to six of these, the extra 3" gets pretty close to the bottom stuff on the black metal panel in the back (charge solenoid, battery studs for chassis & house). You can pull the 6 batt's out to the edge of the tray and probably make it w/no changes, but checking those stud connections will require great attention to avoiding a high-amp short. If you want to push 6 back into the back of the tray, you will need to raise the black panel. Raising the panel will mean enlarging the oval hole thru the frame for the chassis studs.

In any case for 6 batt's, you will need to raise or eliminate the light reel on the rear bulkhead.

[JLMunsil]

Emike, thanks for the reply. I did read you other posts about changing to 6C batteries. I like the idea of only 4 instead of 6 and was looking for an easy way to do it. I think 600AH is enough for me. Sounds like your idea will work fine. I am not sure the positive cable will reach. I may have to get a longer one. Thanks again.

[EngineerMike]

I got longer positive cables- one to the inverter fuse and one to the house positive stud. I got one longer negative cable, the one to the common negative post on the chassis batteries.
The house positive stud cable takes a 3/8" lug on the battery side for the AGMs I got, but a 1/2" on the stud; I got two 3/8 lugs so I had to drill out the stud end; shoulda got one 1/2" and one 3/8.

FYI- the OEM battery cable is copper welding lead, not automotive battery cable, and comes w/tinned lug ends. The 08 cables were then soldered on the ends. I thought earlier they were tinned copper wire but only the ends are tinned w/solder. The welding lead is way more flexible than battery cable for making the tight bends that may be needed.

[JLMunsil]

I have decided to replace my six wet cell batteries with six Lifeline 4C AGM batteries. They are the same size as the wet cell interstates so no adjustments are necessary. Emike, what's the reason for rubber under the batteries? I moved the charge solenoid
up and attached with self tapping screws to make it easier to replace if necessary. (It wasn't easy to get to the nuts even with batteries removed.) Any other things to do while the batteries are out.

[EngineerMike]

My battery tray showed signs that the U2200's did some sliding back & forth which abraded the paint. If you go to AGMs you won't need the volume of air change, and you can put a cushion under the batteries. If you scrub, neutralize, prime & paint the tray first, the plastic or rubber pad should keep the metal in good shape.

While the batteries are out I'd do some additional sealing of the battery case. There is a vertical seam @ back rear corner, a horizontal one at top rear of the jack cover box, the hole on top of jack cover, hole at top forward in frame, and hole in left (rear) bulkhead above the trouble light. Some additional level of sealing these openings will help keep the compartment clean, and it will be easier to do w/out batteries in the way.

[JLMunsil]

Thanks for the ideas. I hadn't thought about the ventilation requirements being less.

[Wayne R]

My filters looked clean at the 4 year 44000 mile mark. They had been changed at 24,000 and 2 years also by Cummings NW.

[Birddog Pilot]

Wayne,
What filters are you referring to? Is there supposed to be a filter/s in the big hole at the aft-upper-left area of the battery compartment? In our '06 the rectangular opening into the engine bay lets all kinds of dirt and crud into the battery compartment. I had been wondering about adding some sort of filter in this area.

[Wayne R]

Dick, I posted in the wrong thread. It should have been in the Hydraulic fluid thread. Look at the time I posted and it may explain my mistake.

[OldForester]

Jim and Sandy,

When I put 8 new standard-size Lifeline AGMS in my battery compartment, we cleaned the compartment with ammonia and water and looked like new.

We also found that we had to put a section of heater hose over the battery hold-downs to insulate them because they were very close to the battery terminals, which aren't has high in the air as the Interstate wet cells were.