Interstate AGM4D battery

rschim · 03-12-2018, 05:14 PM

I have a 2006 E350 RB diesel with both batteries mounted on the frame rail as is typical. I wanted to replace the house battery with a 4D for the larger Ah. According to a receipt that came with the van (previous owners saved everything, good job!) they paid $518 for a new Interstate AGM4D in 2014, which is about right. The only problem is that battery is listed as 21" long. The battery in there is not even close to that long. Methinks something is fishy. Anybody have experience with these batteries? Did they used to be only around 13" long? Just taking a look looks like a job.

Flux · 03-12-2018, 05:19 PM

No way a 4D battery is only 13" in length. No chance.

rschim · 03-12-2018, 05:21 PM

Thanks; didn't think so. Looks like they got ripped off.

joefromsf · 03-12-2018, 06:14 PM

Are you sure there's not another battery installed inside the van?

rallypanam · 03-12-2018, 06:24 PM

Yeah, you may be looking at the original Ford battery, not the SMB added 4D.

Spr · 03-12-2018, 06:28 PM

You referred to “both batteries mounted on the rail”. There should be a third battery (the 4D house battery) most likely mounted underneath the back rear of the van where the spare tire would usually go. The diesel has 2 car batteries mounted on the passenger side under the van which both would be about 13 inches wide.

86Scotty · 03-12-2018, 07:32 PM

Batteries are made and sold in standard sizes according to BCI (Battery Council Int'l) so all 4d's or any other size are the size they have always been, 20.5x8.13x10".

https://www.batterystuff.com/kb/tool...oup-sizes.html

I'm with the 3 dudes above. Diesel vans have one battery under hood and one on frame rail as the chassis batteries (the vehicle came with them). You are looking for a house/coach battery in addition to these somewhere else. SMB did hide them pretty well on some vans, recessed in fiberglass or plastic bins below the floor line but accessible from the interior.