third battery hookup on e350 diesel

[forde350diesel]

I have recently purchased a 2005 e350 extended bed diesel with quigely 4x4. The two starting batteries are 12v, wired in parallel with no isolater and mounted on the frame, below the floor, under the back seat door on the right side. I want to add a third battery and isolate it from the starting batteries for a vent fan and interior lights.

Information on how to add a third battery to an e350 diesel would be appreciated. Where does SMB position the third battery on their ford diesels? Also does anyone know where I can buy a side mount battery box other than from ford?

Thanks!

[daveb]

You should be able to find that information in the electrical section. Much depends on the battery type and size you want to install. This post shows were most 4-D AGM batteries are located from the factory but as you see in the post, SMB installed the first battery inside the vehicle.
viewtopic.php?f=13&t=4926

You should also research battery separators as the new magnetic relays are an improvement over what SMB used in the past.

[shellback]

Not sure what you mean by side mount battery box, but if you want a Ford one that mounts to the frame rail like your starting batteries, they can be found on e-bay pretty reasonable. Just search there for a Frame Rail Battery Box. I hear they bolt right up (existing holes) on the driver's side, but that's just hearsay.
Hope this helps.
Philip

[SheepShagger]

I just posted this in another forum, but here is a copy.

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I wanted to add a 3rd battery to the frame rail on the drivers side, just like the stock mounting on the passenger side (Diesel E350). I know there are other alternatives out their, but I like using stock parts when I can, and none that I have seen as as good as stock anyway.
I managed to find a battery box on ebay for $25, so when it arrived I made up a template for the hole pattern and when I placed it up the the frame, to my surprise Ford have already drilled the holes in the frame rail to mount another two batteries on the drivers side. Great, as I don't like drilling frame rails.
Only problem is the hand brake cable is in the way, rather than cut off the mounting points on the frame, and relocate the cable either up / down or closer to the frame, I decided to just space out the box.
Machined up some spacers, and threaded the last 5mm of the spacer so it holds the bolt to the frame rail to make installing the box easier.


Then it's just a matter of bolting it all up to the holes Ford so nicely supplied.


Here is it, but no cables installed yet. I also bolted up a jump post like the other side.


Added fuses and ML-Series Heavy Duty Automatic Charging Relay - PN 7622 - from Blue Sea Systems next to the original batteries. (Fuse holders are crap, I'm changing them)


And a jump post + fuse on the 3rd battery.


Cab switch for relay, just a temp location for the moment.


Very simple and it took me about 1/2 day to do, but most of that was flaffing about machining up the spacers and getting the size / tolerance just right.

Bolts 7/16 x 2.5 Grade 8 (Nuts & washers)
Spacers were 1 1/4