DC - DC Charger Project

[Yoda]

There is no reason that I can see . . . other than to save 2 cents on a $100,000 truck . . .
See attached pictures of the two batteries.

Rob

Thanks for the pictures Rob and taking the time to put a caliber to show the post is 1/4" I need to get one of those larger calibers. I have a much smaller on in my reloading supplies somewhere.


Scott'n'Wendy "You're going to forget what colour you ordered...lol" Yes the wait can be frustrating at times - as for color, the snow on the ground reminds me. Going Star White as I am tired of the other colors fading/clear coat pealing. I have been told white is more resistant to that.

Thanks everyone for the help
Keith

[Scott'n'Wendy]

I have been told white is more resistant to that.
Keith

The white paint on my Challenger is 28 years old. Still looks good from 15'. Look close and you notice things....

[TedS]

I got white because it doesn't get so hot in the sunshine.

[Jlawles2]

Cate&Rob Rob, by chance are the batteries isolated from each other and only joined when the truck is starting and running? If so this could be a self preservation thing. I know all of my GM's will start and run on one battery as long as it's not cold. I did an amp draw on hot restart on my 04 and found it was a bit over 500 amps to start it. With Glow plugs and starter running, I can see easily approaching the CCA of the recommended batteries.

[Guest]

Cate&Rob Rob, by chance are the batteries isolated from each other and only joined when the truck is starting and running? If so this could be a self preservation thing. I know all of my GM's will start and run on one battery as long as it's not cold. I did an amp draw on hot restart on my 04 and found it was a bit over 500 amps to start it. With Glow plugs and starter running, I can see easily approaching the CCA of the recommended batteries.

With high speed instrumentation, it can be seen to be well over 1000 amps peak.

Jim

[Cate&Rob]

Jlawles2 Guest
Joseph & Jim . . .

I do not know how the two batteries are linked . . . on my list of things of figure out. I can certainly see how cold oil, diesel compression, plus glow plugs could take at least 1000 CCA .

Rob

[Yoda]

Jlawles2 Guest
Joseph & Jim . . .

I do not know how the two batteries are linked . . . on my list of things of figure out. I can certainly see how cold oil, diesel compression, plus glow plugs could take at least 1000 CCA .

Rob

On my last truck they were tied in parallel. The positive cable crossed in a channel on the top back lip of the radiator. It was hard to see as the cables were well shielded. However based on your pictures, Ford may have changed that as none of the positive cables run forward from what I can see.
Keith

[Yoda]

Yoda Keith, let me know how that wire protector works and how you get it over the cable.

Joseph here is a picture of the 1.25 wrap on the 2 awg cables. It was fairly easy to install. The first trick is to lay out the cables with no twist or kinks. Then tape the end so no snags. Then it just a matter of scrunching and smoothing along the cables. I did 1' to 2' at a time then worked it down the cable line. I think I like it better than the split loom.


I thought I would pre-assemble some things as I had time today The covering is over 2-2awg cables. I covered the first 25'. This should reach from the engine bay back to the bed plug. I tried the 1" covering I had - it worked too, but was a lot tougher to work with over this size cables, so I will save it for the single cable runs.

Link to the covering
https://www.amazon.com/gp/product/B0...2?ie=UTF8&th=1

Keith

[Guest]

On my last truck they were tied in parallel. The positive cable crossed in a channel on the top back lip of the radiator. It was hard to see as the cables were well shielded. However based on your pictures, Ford may have changed that as none of the positive cables run forward from what I can see.
Keith

Keith,

They should be tired in parallel since the OEM would not install a second battery if it was not needed for the primary function of cranking.

Jim

[Scott'n'Wendy]

No isolation in the Dodge diesels. I would be very surprised if any make has isolation due to the high current demands put on them. It would have to be a very heavy duty isolator to survive.

[Yoda]

OK folks. As i have the truck, time to move on with the install. I only want to drill holes once and get it right. I found a spot, I think, for the solenoid. Its drivers side fender toward the firewall. I need to find a way to see or feel behind this area so I don't damage anything. As the truck body is aluminum I believe I should be using stainless steel hardware - correct?

Battery stud size - per Ford the OEM battery accessory studs are 6MM x 1.0, or roughly 1/4': as Rob measured. I need to get some nuts to verify, I want to confirm this is big enough for the roughly 80A + max draw of the Renolgy 60A DC-DC I have. I plan to drill and tap the drivers side battery terminal and plan to tie in both positive and negative cables to the drivers side battery. I am doing full positive and negative runs to the charger (fully isolated ).

Well enough for the first questions.

Thanks

[ncitro]

Yoda Sounds good. I think things are reversed a bit from wren I did mine, but mine is wired on the passenger side based on where my upfitter wiring was I think. I did not screw my solenoid to anything, I used the larger industrial zip ties through a couple holes I found in the inner fender. 15,000 miles and it hasn't gone anywhere. I have the 40A version and ran 4AWG. I originally had a 60A breaker and found it would on occasion trip. I went up to a 100A breaker (still safe for the 4AWG) and haven't had a trip yet. I say that to caution you that you might want more than a 80A breaker for the 60A unit.

[Yoda]

Yoda Sounds good. I think things are reversed a bit from wren I did mine, but mine is wired on the passenger side based on where my upfitter wiring was I think. I did not screw my solenoid to anything, I used the larger industrial zip ties through a couple holes I found in the inner fender. 15,000 miles and it hasn't gone anywhere. I have the 40A version and ran 4AWG. I originally had a 60A breaker and found it would on occasion trip. I went up to a 100A breaker (still safe for the 4AWG) and haven't had a trip yet. I say that to caution you that you might want more than a 80A breaker for the 60A unit.

Thanks Neil
I am using 2 awg for the wire runs with a 100A fuse at the battery terminal and an 80A circuit breaker between the charger and the battery. Thanks for the tip on looking over by the up fitter switch block. There sure is not a lot of room left over under the hood. I think there may be room over by the up fitter block too, but a much longer wire run would be needed. There may be room on the frame under the driver seat, but I was hoping to provide protection to the solenoid. No matter what it is going to be a tough fit.

Keith

[ncitro]

Yoda Yeah mine has to zig zag over from the passenger side to the drivers side where I mounted the outlet in the bed. Would have been nice to have it on the driver's side for sure.

I also used these to go on the cable where they go onto the breakers and solenoid:

Fastronix 5/16" - 1/4" Stud Terminal Cover 2 Pack (Red) https://a.co/d/dAszFDg

[Yoda]

Yoda Yeah mine has to zig zag over from the passenger side to the drivers side where I mounted the outlet in the bed. Would have been nice to have it on the driver's side for sure.

I also used these to go on the cable where they go onto the breakers and solenoid:

Fastronix 5/16" - 1/4" Stud Terminal Cover 2 Pack (Red) https://a.co/d/dAszFDg

Great minds think alike. I have them in several sizes in the project box - I am sure I have extras. I am hoping to fit the solenoid on the drivers side, then all I need is wiring to cross over from the up-fitter box. Somewhere I have some small high temp split loom I can run across the back lip just below the hood.

Thanks again fro your help
Keith