truck charging trailer

[SRS]

Originally Posted by Centex

That's what I did when I did my lithium installation as a precautionary measure, I just didn't want to have any concerns about high voltage DC effects on any trailer devices.

Like your case my solar takes care of my battery charging needs, I do not have any charging connection to my vehicle, I've only connected to shore power when I wanted extended air conditioning (I can run my mini-split off my battery for a few hours of daily respite without problem). I have a pair of Eu2000 generators for use on my rural property but have never carried one while trailering.

So, thus far I've not had a situation where an IP22 would be needed or useful, but I'm thankful that you shared your experience and helped me understand how it can be useful.

No plan to immediately install one but I'm definitely keeping it in mind as a 'someday' contingency device, thinking that might be a good idea when I finally swap my LP fridge for a compressor model.

I'm intrigued by the discussion between you and Perry regarding the use of a DC-DC charger to reduce the voltage from lithium batteries to protect the DC components. Being an Electrical wiring novice, Im hoping you could answer some questions I have about how one would go about setting that up?
1. Which model would you use. Would the Orion 12/12 18 be sufficient? Isolated or non-isolated?
2. Where in the electrical system would this be located? Looking at my wiring diagram, would that be between the battery cutoff switch and the converter-power center?

I recently installed the Progressive Dynamics PD4655L. While most of my camping is boondocking or sites without shore power, a couple of days before I go I plug the trailer in to run the frig. The PD4655L takes my 200ah of lithium up to 14.5 volts. and keeps them there while plugged in. So, I'm a little concerned about some of the components.

My trailer has the full ETI lithium package and an inverter with the power transfer switch. I have 2 100ah HubLion batteries in parallel. Attached is the wiring diagram which is pretty accurate, I think.

Appreciate any insight or direction you can provide.

Thanks,
Sherby

[Centex]

Originally Posted by SRS

....
1. Which model would you use. Would the Orion 12/12 18 be sufficient? Isolated or non-isolated?

I am using the Victron Orion-Tr 12|12-## Isolated DC-DC converter, where ## is the maximum amp output of the converter. They are available with several amp-capacities, you would select that based on the sum of DC loads you power through the converter. These can be connected in series to increase total amp capacity if desired.

I elected to have regulated DC ampacity for everything in my trailer except the stabilizer jacks, breakaway brakes, and inverter (those being powered via an un-regulated bus). Probably overkill but it made the DC power distribution easier for me.

These are only for voltage regulation / stabilization, they only provide a single fixed-voltage output (configurable, I'm set at 12.8VDC output), so do not offer any multi-stage battery charging capability.

Though the units are only available as 'isolated', that is forfeited the way I've installed them (input and output share a common ground), which is perfectly OK for my purposes.

Originally Posted by SRS

....
2. Where in the electrical system would this be located? Looking at my wiring diagram, would that be between the battery cutoff switch and the converter-power center?

FYI / FWIW here's a schematic focused on the Regulation part of my system. I do not have any 'power center' analogous to the OE WFCO, I have an all-in-one Xantrex Freedom XC providing converter/ inverter/ charger/ transfer switch functions and a dedicated / stand-alone fuse panel for DC distribution. Your's may well differ, but the basic concept should still apply.

Hope that helps, Have Fun!

[SRS]

Thanks Alan, I appreciate the info and it gives me more food for thought. Much appreciated.

[quidoi]

I am with you John in santa cruz--- i am about to add the two lithium to my system and would like to know where to disconnect the wire that is in the trailer that goes to the 7 pin connector is it the red wire connected to the thermal fuse before the battery -- i am not going with dc- dc charger-- thanx

[Centex]

Originally Posted by quidoi

I am with you John in santa cruz--- i am about to add the two lithium to my system and would like to know where to disconnect the wire that is in the trailer that goes to the 7 pin connector is it the red wire connected to the thermal fuse before the battery -- i am not going with dc- dc charger-- thanx

Suggest you follow your umbilical cord from the vehicle into the trailer. When you find the junction between the umbilical cord wires and the trailer wires, disconnect and insulate ONLY the umbilical cord 12V battery charging wire from the vehicle, leaving all other trailer-side wires joined and intact.

That will cut the connection between the battery and the vehicle while ensuring that the other loads using that wire to/from the battery (e.g. breakaway brake, maybe others) remain functional.

If you sever the vehicle>battery connection at the 'battery-end' of the circuit you risk unintended consequences (e.g. loss of breakaway brake function) because the wire to the front of the trailer serves multiple purposes.

The pic shows that in the exterior-mounted junction box where the umbilical meets the trailer wires on my 5.0. Your bumper-pull junction box may be physically different (and more difficult to access being inside the trailer?) but the wiring should be the same in concept.

Hope that helps, Have Fun!

[John in Santa Cruz]

yeah, the brake breakaway switch HAS to be directly connected to the battery + so if your trailer gets loose, the brakes get slammed on

[hugh]

Originally Posted by quidoi

I am with you John in santa cruz--- i am about to add the two lithium to my system and would like to know where to disconnect the wire that is in the trailer that goes to the 7 pin connector is it the red wire connected to the thermal fuse before the battery -- i am not going with dc- dc charger-- thanx

FWIW, I've got a large lithium battery bank (920Ah) and never bothered disconnecting the charging wire in the 7-pin connector. There's just too much resistance in the wire runs for it to make that much difference compared to a lead-acid battery.

[John in Santa Cruz]

Originally Posted by hugh

FWIW, I've got a large lithium battery bank (920Ah) and never bothered disconnecting the charging wire in the 7-pin connector. There's just too much resistance in the wire runs for it to make that much difference compared to a lead-acid battery.

yeah... but you need to disconnect it up front near the trailer pigtail, as there's only one wire from the trailer power stuff to the front that goes to both the pigtail and the breakaway switch. the breakaway switch MUST be powered from the trailer.

and... wow, 920AH... Thats like 12KWH. you running your air conditioner off that or something? I can camp a solid week with my 5000 WH batt but I don't even dream of running A/C off DC

[hugh]

Originally Posted by John in Santa Cruz

yeah... but you need to disconnect it up front near the trailer pigtail, as there's only one wire from the trailer power stuff to the front that goes to both the pigtail and the breakaway switch. the breakaway switch MUST be powered from the trailer.

and... wow, 920AH... Thats like 12KWH. you running your air conditioner off that or something? I can camp a solid week with my 5000 WH batt but I don't even dream of running A/C off DC

Yes, I sized it to run the AC in the summer, and the pipe / tank heaters in winter. It's also nice to be able to run things like the convection oven, electric blankets, etc. without having "amp hour anxiety".

[boardhead]

Yes you can. Run your engine. I have done it and it didn't take very long.

[Toddybegood]

My '21 tacoma has a high capacity alternator as part of the tow package. I just leave truck and trailer 7pin hooked and hit the remote start from inside the trailer (which lasts for 10minutes) if I feel the need. I have an unreliable red yellow green light for the battery monitor and two mismatched 7 year old batteries. Ha ha oh man.

[Chamberman]

The alternator isn't typically the limiting factor. Most modern alternators are more than capable of handling the 30A RV connection. The limiting factor is usually the gauge and length of wire and the mechanical connections. This will typically limit you to well under 30A. Just so you know your two batts are probably the 220AH variety. That means you have 110AH of usable storage. If you run the vehicle for 10min with a perfect 30A flowing then you put 5AH back into your batteries. So it takes a lot longer than just a few minutes to top a battery off, unless the battery capacity is down due to age or failure.

[quidoi]

Originally Posted by SRS

I'm intrigued by the discussion between you and Perry regarding the use of a DC-DC charger to reduce the voltage from lithium batteries to protect the DC components. Being an Electrical wiring novice, Im hoping you could answer some questions I have about how one would go about setting that up?
1. Which model would you use. Would the Orion 12/12 18 be sufficient? Isolated or non-isolated?
2. Where in the electrical system would this be located? Looking at my wiring diagram, would that be between the battery cutoff switch and the converter-power center?

I recently installed the Progressive Dynamics PD4655L. While most of my camping is boondocking or sites without shore power, a couple of days before I go I plug the trailer in to run the frig. The PD4655L takes my 200ah of lithium up to 14.5 volts. and keeps them there while plugged in. So, I'm a little concerned about some of the components.

My trailer has the full ETI lithium package and an inverter with the power transfer switch. I have 2 100ah HubLion batteries in parallel. Attached is the wiring diagram which is pretty accurate, I think.

Appreciate any insight or direction you can provide.

Thanks,
Sherby

I have a similar ETI wiring diagram and setup but does 8 AWG wire seem the right choice ? I am also in the process of setting up two 100 amh batteries but am connecting batteries via 4AWG wire-- my question is 4AWG adequate from batteries to 3000 watt inverter? also is using 4 AWG from batteries to the converter oversizing or use the ETI suggestion of 8 AWG adequate enough?-- thanx for any input

[John in Santa Cruz]

I don't think 18A DC is enough for an Escape 21.. the 10 speed Maxxfan Deluxe can draw 6-7 amps on high plus another amp when its opening or closing the vent... All my LED lighting on at once is aroudn 6-7A too. Ok, maybe 18 A is sufficient? Hmmm.

Its going to be tricky wiring that into a standard WFCO or similar power center... the 55A max output of the WFCO (or PD or ...) voltage converter goes to the fuse panel, and the battery comes directly off that fuse panel, as do all the fused DC circuits. You'd probably need to move all those fused DC circuits to a separate fuse panel/box, driven by the 12/12-18, and feed the 12/12 from 1 circuit on said original fuse panel, fused at 20 or 30A.

[John in Santa Cruz]

Originally Posted by quidoi

I have a similar ETI wiring diagram and setup but does 8 AWG wire seem the right choice ? I am also in the process of setting up two 100 amh batteries but am connecting batteries via 4AWG wire-- my question is 4AWG adequate from batteries to 3000 watt inverter? also is using 4 AWG from batteries to the converter oversizing or use the ETI suggestion of 8 AWG adequate enough?-- thanx for any input

I believe my 2000W inverter is powered via pairs of AWG4 acting as AWG2, as it can draw close to 200 amps. each of my LiFePO4 batts is connected to a + and - bus bar via AWG4, with 150A fuses in the + leads. and the dual AWG4 wires to the inverter come off said bus bars.

a 3000W inverter could draw around 300 amps (inverters aren't 100% efficient, and there's current surges at power on and stuff), 300A for a few feet probably should use at least AWG 0. This table suggests 2/0 (aka 00) for 200A up to 20 ft for non critical 10% voltage drop. If your wires are air spaced and not tightly bundled, they can handle a bit more power than this table suggests. Absolutely for sure use high quality 100% pure copper fine stranded wire like welding cable. I've gotten some quite good fine strand copper wire from WindyNation via Amazon. https://www.amazon.com/gp/product/B01M35S1J2

[Centex]

Originally Posted by quidoi

... my question is 4AWG adequate from batteries to 3000 watt inverter? ....

Perhaps of interest .... Circuit Wizard - Blue Sea Systems

Note that the length of conductor is the complete circuit (positive+negative return).

This calculator typically provides conservative solutions (meeting rather rigorous AYBC standards)

[John in Santa Cruz]

Originally Posted by Centex

Perhaps of interest .... Circuit Wizard - Blue Sea Systems

This typically provides conservative solutions (meeting rather rigorous AYBC standards)

FWIW, I snagged that table I posted above from Blue Sea

frankly, I'm not sure what the use case is for a 3000W Inverter. a solid 2000W true sine inverter will run a typical RV air conditioner just fine, my Coleman whatever-they-installed-in-2014 draws about 7-8A off the AC once its running and doesn't pop a 15A breaker running it off a AWG 12 100 ft extension cord from my house.

[quidoi]

Originally Posted by Centex

Suggest you follow your umbilical cord from the vehicle into the trailer. When you find the junction between the umbilical cord wires and the trailer wires, disconnect and insulate ONLY the umbilical cord 12V battery charging wire from the vehicle, leaving all other trailer-side wires joined and intact.

That will cut the connection between the battery and the vehicle while ensuring that the other loads using that wire to/from the battery (e.g. breakaway brake, maybe others) remain functional.

If you sever the vehicle>battery connection at the 'battery-end' of the circuit you risk unintended consequences (e.g. loss of breakaway brake function) because the wire to the front of the trailer serves multiple purposes.

The pic shows that in the exterior-mounted junction box where the umbilical meets the trailer wires on my 5.0. Your bumper-pull junction box may be physically different (and more difficult to access being inside the trailer?) but the wiring should be the same in concept.

Hope that helps, Have Fun!

Thanx Centex and John for input-- hopefully my attachment showing my junction box -- it appears that the far right is the ground and the next post to the left is the power coming in from the battery for which one wire as i can trace from the breakaway switch goes on and just want to make sure which wire i can pull that is for charging -- i believe it is the other black wire ? thanx

[quidoi]

Originally Posted by quidoi

Thanx Centex and John for input-- hopefully my attachment showing my junction box -- it appears that the far right is the ground and the next post to the left is the power coming in from the battery for which one wire as i can trace from the breakaway switch goes on and just want to make sure which wire i can pull that is for charging -- i believe it is the other black wire ? thanxAttachment 76775

--

to all ya-- got it figured out after tracing the wires and reading my ETI manual which shows the battery charge wire is the black one ... i initially did not see it-- thanx all-- waiting for a few more components to complete the lithium convertion-- may need to contact you should i have other needs -- thanx

[hugh]

Originally Posted by John in Santa Cruz

FWIW, I snagged that table I posted above from Blue Sea

frankly, I'm not sure what the use case is for a 3000W Inverter. a solid 2000W true sine inverter will run a typical RV air conditioner just fine, my Coleman whatever-they-installed-in-2014 draws about 7-8A off the AC once its running and doesn't pop a 15A breaker running it off a AWG 12 100 ft extension cord from my house.

I find our 3000w inverter to be useful. I can run the AC and cook a pizza in the convection oven at the same time.