DC - DC Charger Project

[howson]

Yoda

Only .02 to add is make sure the connections are high quality, pure copper and the diameter of the lug must match the stud installed on the battery snugly. Too much "slop" and there's a real possibility of resistance at the connection. Resistance = power loss and heat build up (obviously not a good thing). When running there will be up to 60+ amps running through the wires to/from the truck's battery.

No doubt you remember my problem was opposite of yours--I had to install a lug on the negative side of the battery terminal (passenger side). I've had it off a few times to inspect for heat damage or corrosion build-up. So far everything looks good so I don't have any concerns other than the standard BE CAREFUL when working around those batteries!

And yes, I know all about whacking my noggin on anything within arm's reach.

[Hogdrv]

Those are the cables I followed to the back, worked great and you can see in my picture where I ran the upfitter wire. Sounds good to me!
The drilling by the battery does scare me though and yes BE CAREFUL!!!!!
Jim

[Cate&Rob]

I am going to drill and tap this terminal for the new 6mm positive post. This is on the drivers side. I am thinking of doing it on the battery
Am I nuts for thinking this?

I would not try to drill and tap that terminal while it is on the battery. A slip of the drill and you have bigger problems. Also, that terminal is too thin to tap with sufficient threads to secure the connection and the tap will have to go through farther than the distance to the top of the battery to cut full threads. Better to remove the terminal, drill it in a safer location and install a bolt from the bottom and nut on the top for a secure connection before reattaching to the battery (in my opinion).

Rob

[Yoda]

Yoda

Only .02 to add is make sure the connections are high quality, pure copper and the diameter of the lug must match the stud installed on the battery snugly. Too much "slop" and there's a real possibility of resistance at the connection. Resistance = power loss and heat build up (obviously not a good thing). When running there will be up to 60+ amps running through the wires to/from the truck's battery.

No doubt you remember my problem was opposite of yours--I had to install a lug on the negative side of the battery terminal (passenger side). I've had it off a few times to inspect for heat damage or corrosion build-up. So far everything looks good so I don't have any concerns other than the standard BE CAREFUL when working around those batteries!

And yes, I know all about whacking my noggin on anything within arm's reach.

Howard
Theses are the terminals I am using https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Now I just checked the fit on my 6mm bolt I was thinking of using as a stud. There is a slight amount of slop - same with the fit on the Ford aux post. It's easy to slip on. The site description says its the proper size "This particular variant has a 1/4" Eyelet suitable for use with 2 AWG (2 Gauge) 35 sq. mm Cable & 1/4" (M6) " The 5/16 I got for the solenoid have a little less slop , but still slip on easily.

I hope I chose wisely?

Keith

[howson]

I hope I chose wisely?

The lug recommends a 1/4" stud. That equals 6.35mm according to a conversion website. Given the contemplated 6 mm stud on hand is used, that means there's .35mm of "slop" which is a whopping 0.01377953 inches. I'm not an engineer...but I'd guess the 6mm will work fine, though getting the recommended hardware is the safest approach.

I do like the specs on the lug you chose--should hold up well for the use intended.

To ease your mind set a reminder to do a follow-up inspection a month or so after installation (and a few actual uses). If there's an issue, it will be obvious due to discoloration or corrosion. I suspect it will be fine. (Even if you install a 1/4" stud I'd still suggest doing the follow-up inspection.)

[Jlawles2]

Yoda Again Keith, the step drill and a slightly undersized hole on the terminal can be corrected if needed. If you look around a bit, sometimes you can find undersized holes on terminals. When all else fails, a piece of properly sized copper pipe, a good hammer or vise, some file work, and the step drill become friends to make a terminal.

[Yoda]

Today I got out the Renogy 60A DC-DC charger and actually read the instructions. I found a place to mount and actually figured out I need to be careful otherwise I could put a screw through the bedroom floor

DIP settings - could use your your help.

Per Crown battery they provided the following information on Charging.
Voltage Setting
12V
Absorption/Bulk
14.5
Equalize
15.5
Float
13.5

However the DIP switched do not exactly line up
Choices
Absorption 14.4V, 14.1V, 14.7V
Float 13.8V. 13.5V. 13.2V

I am thinking of going with the 14.7 absorption and 13.5V float
I have also sent an email to Crown Battery.

Thoughts?
Keith

[Country Campers]

I would recommend the 14.4 v for the float, it might be kinder to the battery. Hopefully Crown Battery will give you some info.

Brian

[ncitro]

Yoda I agree with Brian, I would go below not over unless they recommend otherwise. If you go over you will need to check your water more often as its likely to boil out.

[howson]

Yoda ... maybe I haven't had enough coffee this morning, but for a Battle Born Absorption is 14.4v and Float 13.6V. From the Solar MPPT configuration:



For the actual switch setting, but I went through the same ???. For the 40A the settings are documented in my thread.

Howard

[Yoda]

Yoda ... maybe I haven't had enough coffee this morning, but for a Battle Born Absorption is 14.4v and Float 13.6V. From the Solar MPPT configuration:



For the actual switch setting, but I went through the same ???. For the 40A the settings are documented in my thread.

Howard

LOL you do need more coffee. I have 4 - 6V deep cycle Crowns CR260 flooded. The chart I posted was Crowns commendation. I am still in the dark ages on batterys.
Thanks though
Keith

[Yoda]

I got the answer back from Crown. As the absorption phase is time limited to three hours he recommends the 14.7 and watch.
Keith . He also sent along a maintenance guide that others might find useful.

I’d start with 14.7V & 3 hours; you can always dial one or both back if you begin to see excessive overcharge…

Bottom line on battery care / maintenance – the “lighter” you are on the batteries, the longer they will last and the easier the maintenance and care will be…

Key point again though is regular use of hydrometer to ensure batteries stay balanced…

Please let me know if you need any other assistance here Sir – thanks!

Safety First Guidebook - Renewable Power Batteries_R0422.pdf


Thanks
Keith

[Yoda]

Over the past few days as time allowed I have 90% of the equipment and wiring in the trailer completed. First task was running the two #2 welding cables from the pin box to the front bay. I used some plastic coated utility wire (thick bailing wire) and snaked it to the from bay from the pin box area. I did undo the two field bolts either side of the pin box that holds the underside panel up. Took about 3 tries as it kept hanging up in the insulation. An electrical fish tape might have been better.

At the pin box I used the same
restraining clamp that the 7pin cord used and secured the two lines together.


Up in the pin box I found and opening to run the cable through, This took a bit of fishing to get the cable pulled up and through, I first pulled it out flan right at the pin box, right on top of the panel, then fished a wire through the hole and then pulled the cable up. TIP - be sure you don't have any twists or kings in your cables as it can conpound


Truck end is the same as the 7 pin cable. I need to get the Anderson plug installed.

Sorry for the bad photo, but this is the cable running forward on top of the panel to the king pin.

I then zip tied it to the angle supporting the bed room floor. I mounted the DC_DC unit to the ceiling after making sure the power cable bend would work - took several iteration to find the right spot. And YES this time I zip tied to the propane cross over tube instead of drilling and installing clamps.

[Yoda]

Ok for the rest of then component install

As mentioned before I mounted the DC-DC unit to the front bay ceiling which is also the bedroom floor. This material is only 1/2 - 5/8 thick so you need to be careful of your screw length. The Renogy only has 4 - #8 mounting holes, so to help with a strong bond I used some 3M extreme mounting tape on mounting bracket full width on either end. The middle of the unit is spaced off the mounting brackets, so I did not use any mounting tape there. I think they want this air gap for cooling. I put the outlet side forward to be able to see the indicators easily.



I then found a spot for the 80A isolation breaker. I wanted a spot that was a direct shot to the power in assembly as possible. It too is mounted using the 3M mounting tape and 2 - #10 screws, being careful to space them out so they did not penetrate the floor.

I now have it wired in to my Power in bar for the positive and I ran the negative to the master ground bar I put in with the Multiplus. Pictures to come.

I think at first I am going to limit the output to 30A to get an idea of the operation. I also plan to get the D+ signal from the trailer clearance lights.

Thought so far?

Keith

[Yoda]

Ok the trailer side is 99% complete. I just need to connect up the temperature probe. It is a true probe, so I was going to stick it down in between the 4 batterys at the inside corner

Wiring - this was a fun day (NOT!) as I kept banging my head against zip ties I had installed previously. I swear I left a pint of blood and used up a box of bandaids - they did provide protection and padding. It was also hot - high 90's.


First thing I did was assemble my Anderson connector on the trailer power feed. On thing I learned the hare way is verify how the connector fit inside the cover and make sure you have the positive/negative wires on the correct side. Also when crimping on the pins, be sure the are rotated correctly (flat side t outer wall). I now have a slight twist in my cables as I goofed on this. Now if your wondering setting up the cable en like this will make it difficult to use the bulkhead fitting in the truck - I would need to pull the cover back along the cables. I am rethinking the truck connection. I wanted the ends fully covered so dirt and water wold not get in.

This is looking up at the output feed. I looped behind a structure member and looped towards the back of the front bay. The negative line goes to the back wall and then down to the main negative buss bar. The positive cable runs over to the circuit breaker. After the photo I used some 3M squares and zip tied the wires to the upper cross member..


Positive wires connected to circuit breaker

I then ran the positive and negative side to the propane cross over tube and combined then (zip tied as the cross over each other, center of photo) at my central wire run.