Trailer power

[FrazzledHunter]

We spent all day at Overland East. We found a trailer - Kimberly, that has a separate high power dedicated battery charging cable that can connect to the tow vehicle! The company owner was there and we had a lengthy discussion on this topic.

 

[Fisher23]

How much $$ was the Kimberly?

 

[FrazzledHunter]

How much $$ was the Kimberly?

The one we looked at was their smaller one, single axle E series. It's the perfect size for us. It was the trailer's owner showing it; got lots of practical questions answered. They said they paid total $100K. Shipping was $10K from Australia.

 

[FrazzledHunter]

Here's the Kimberly E series we looked at:

 

[FrazzledHunter]

Some decisions were made on our end. We decided to go with an upgrade to the OEM alternator rather than add a second one. The one we decided on is the Smart Battery Charger (M2K) 390 amp.
REF:
390 Amp - Toyota 3UR-FE (LIN) | SBC - https://smartbatterycharger.net/product/390-amp-toyota-3ur-fe-lin/

The LC idles at about 700RPM warmed up, parked. This RPM is pretty good for generating power however I took it for a test drive and noted that the LC can sometimes idle lower, around 550 RPM. This could actually be quite common as we sit stuck in traffic somewhere. So, after some back and forth regarding the LC's RPM at idle going as low as 550RPM (in gear, warmed up, on brake at a stop light or sitting stuck in traffic) we decided to use a slightly smaller 2" diameter pulley rather than the 2.46" pulley that usually comes with it.

The "standard" 2.46" sized pulley gives about a 3:1 alternator to engine RPM ratio. Meaning at 550 RPM we have an alternator spinning at 1650 RPM (550x3) 130A which we thought was a tad low. The smaller pulley that will ship with the unit is a 2" pulley. The 2" pulley offers a 3.45:1 RPM ratio and should spin the alternator at approx 1900 RPM almost 200A - better at the low end of the RPM scale .

But, the smaller pulley triggers a possible complication in that it MAY require a slightly shorter belt, by 10mm. Even though the tensioner pulley should be able to take up this slack I'll order a shorter belt just in case and leave up to the installer to use it or not.

I should have it in about 2 weeks and installed hopefully a week later.
The plan is to get it installed and burn it in, so to speak, for about a month.
Story at 11.

 

[FrazzledHunter]

I said story at 11 so I'll mention this here as there are often multiple different paths to an answer:
Alternator upgrade - done! - https://forum.ih8mud.com/threads/alternator-upgrade-done.1329033/

 

[FrazzledHunter]

So the new alternator is doing great so far. The next step is to get it wired for the extra power to the battery and then to an Anderson connector on the driver's side at the bumper.

I'd like to run the black/- from the connector at the bumper to the frame near the rear bumper. There are a couple of threaded bolt holes near there on the frame on the side near the KDSS valves I could use but that leaves the ground very exposed to the elements. The wire gauge I think I'll use is a very conservative 0AWG.

1. I'd be interested on any ideas on where best to snatch a ground on the frame.
   1. How to protect it if it's exposed underneath?
2. Should I try and get the ground wire up to the cargo area at/near where the inverter is located to better protect it?
   1. This would lengthen my return path a bit.

Other thoughts?
Any ideas appreciated!

 

[Fisher23]

I ran my 6 awg wires for the 50amp Anderson from the rear bumper, up through the hole in the floor to my bus bars in the cargo area (with breaker on both +pos ends). I did that as I'm running a dc to dc to the trailer.

For ground you may want to use a bumper frame bolt since you are grounding to frame.

On the 200 there is a hole under the tail gate in the center.

This is mine. I still need to add a plug in the hole to avoid chaffing. I have arb swing outs which is why I selected that location. Other bumpers have better options.

 

[FrazzledHunter]

For those of you that have powered your trailer from your tow vehicle with a DC-DC charger...

Did you use a charger with a common or an isolated ground?

 

[FrazzledHunter]

Trailer has been acquired and power upgrades are done.
All upgrades done by the dealer pre-delivery, General RV West Chester, PA.

• Anderson SB-175 in Trailer Vision weatherproof housing at tongue.
• 4GA wire into the trailer to a new REDARC BCDC 1250D dual input charger.
  • REDARC BCDC set to Lithium charging.
• ZAMP connector on side of trailer which went straight to the batteries has been re-routed to the REDARC's solar MPPT input.
  • Manufacturer's configuration required ZAMP regulated solar panels; now any unregulated solar panel such as my Merlin XP-170 panels may be used

Battery area - placement of new components per my spec to accommodate future additional chargers, controllers and batteries

• Factory
  • 2 100Ah Expion 360 Lithium batteries
    • 2 more are going to be added for 400Ah total
  • Xantrex 2000W inverter
  • Expion 360 MPPT controller for 400W roof solar panels
• New/custom
  • Cutout switch for Anderson connector, rear center
  • Power posts, rear right
  • Newly added REDARC BCDC charger, right rear corner
  • REDARC BCDC Yellow wire connected to ZAMP connector on side of trailer
    • Formerly connected straight to battery bank; required either regulated solar panels from ZAMP or MPPT controller to adapt other manuf. solar panels to charge the lithiums
    • Allows me to use my existing Merlin XP-170 solar panels in addition to the solar panels on the roof
  • Additional fuses, not shown

The LC goes into the shop next week to have the alternator's wiring upgraded and the line added to the rear bumper.

Almost there.

 

[FrazzledHunter]

Just got the LC back from the shop.
Alternator wiring has been upgraded.
Wiring has been added to the rear bumper.
The die is cast. The circle is closed.
It's taken almost a year.
We're done.*
*For now.

EDIT: all work done by No Limit Baltimore
No Limit BMORE - https://www.nolimitbmore.com/
SB-175 at the bumper

• 500A ignition actuated relay
• 120A breaker for the Anderson SB-175 at the rear bumper
• 60A breaker for the Anderson SB-50 at driver's side
  • 6GA wire from breaker to driver's side foot-well to be added future
• Slee compressor bracket

 

[rlynch356]

Fuse both ends, or better yet use a circuit breaker on the car side at least so it’s easy to disconnect.
run your wire down the frame to an Anderson plug.
I’d probably size up the wire due to voltage drop from the length since you are charging a battery

But definitely protect both sides with a fuse since it’s 2 batteries

 

[FrazzledHunter]

Fuse both ends, or better yet use a circuit breaker on the car side at least so it’s easy to disconnect.
run your wire down the frame to an Anderson plug.
I’d probably size up the wire due to voltage drop from the length since you are charging a battery

But definitely protect both sides with a fuse since it’s 2 batteries

That's what was done.

 

[rlynch356]

rgr.. guess I shouldn't read on my phone

 

[FrazzledHunter]

rgr.. guess I shouldn't read on my phone

Happens to me all the time.

 

[FrazzledHunter]

Next up...add 2 100Ah lithiums to the trailer.
I just can't sleep with all that empty space in the battery compartment.

To be continued...

 

[FrazzledHunter]

Our truck was not yet upgraded with the DC connector at the time of trailer pickup and the DC charger therefore could not be tested on-site at General RV.

The truck upgrade was completed the week following pickup and yesterday I was finally able to conduct a complete end to end test of charging the trailer from the tow vehicle.

I am happy to report it was a complete success!

I do not have a direct measurement of the DC current flowing to the REDARC unit but I observed the rate of change to the % charge as reported by the battery management system. I hope to get direct DC power measurements from the tow vehicle to the trailer, at some point.

Observing the rate of charge by looking at the charge % it appears that I am able to charge the batteries from the tow vehicle at approximately the same rate as via the converter connected to shore power. I was able to measure input to the trailer using an AC watt meter at approximately 700W @ 120VAC. Note I was careful to make sure that the trailer wasn't running anything AC other than to the converter for battery charging. My AC measurement obviously included converter inefficiencies, but that's OK since I was after how much power actually was being used to charge the batteries.

It also means that, if I'm careful not to run any extra AC in the trailer, I'm able to easily charge the batteries with our small 1000W Honda generator!

This is simply awesome IMHO.

<I HATE ZAMP>
The ZAMP connector was initially connected by inTech directly to the batteries requiring the use of solar panels that were regulated.
Adding the dual input REDARC enabled me to re-route the connections from the ZAMP to the REDARC's MPPT input enabling me to use my existing Merlin XP-170 panels or any other unregulated panel.
I'm making an adapter for that vomitous ZAMP connector to an Anderson SB-50.
</I HATE ZAMP>

This is a diagram of what I have on EDIT: added to the trailer:

 

[FrazzledHunter]

I finally did some testing on the Zamp auxiliary solar connection which I had the dealer connect to the REDARC's solar input.
To do the testing I first had to make a polarity reversing Zamp to SB-50 adapter; 10 GA wire.
It's probably the only one in existence.

The test which was done in the morning had the 2 400W roof panels putting out a combined 240W and the portable Merlin XP-170 panels we've been using all along with our Yeti 1500X portable battery, putting out 115W. So it's a real gain. I suspect that the rooftop panels were a bit inhibited due to the partially shaded lot.
Zamp connector on trailer:

Polarity reversing Zamp to SB-50 adapter:

Merlin XP-170 solar panels:

 

[FrazzledHunter]

Just got two new 100Ah batteries added. Had to relocate the heater hose grrrr.... see post #50 above.

Also added a heating pad custom made for me by ultraheat which will hopefully keep the batteries warm enough to charge in cold weather. These are the same folks that make tank heaters for RV's & trailers. The pad is mounted along the battery compartment wall at the side of the batteries. It's controlled by a thermostat/relay that kicks on at 35F and off at 45F. There's also a remote switch that turns it off or on. This is a bit of a science project so story at 11.
REF: LiFePO4 Lithium Battery Warmers | UltraHeat - https://www.ultraheat.com/batterywarmers

With 400Ah total it just might be enough. We'll see!

 

[FrazzledHunter]

As I mentioned I just got the battery upgrade from 200-400Ah done this winter. But I haven't tested the charging from the LC post install. Previously I had tested charging by looking at the central charging panel which includes charging from all sources, like the solar panels. But you could come close by looking at the charging power before and after. With the LC connection I observed that the charging total went up to about what was delivered by shore power - 650W. So I estimated that 600+ watts was going to t he trailer.

But I never did a direct measurement from the LC's rear bumper to the trailer. Sooo with some adapters I bought over the winter and just because, I decided to perform an actual measurement of the charging power on the 4 battery bank and got 604.5W/45.66A/13.24V into the REDARC BCDC 1250D.

It's just what I'd hoped but I'm a bit surprised it isn't higher like 50+A. Now as to what the REDARC is putting out EXACTLY to the batteries remains a mystery. I'll save that science project for another day.

To do the measurement I put together this contraption which consists of a SB-175 to dual SB-50 adapter, power meter, SB-175 to SB-50 adapter: