AC charging a tow vehicle while driving

[luthj]

My mistake, I got your posts confused. The TOAD device appears to be a simple relay. The Victron DC-DC definately can boost output. And yes, the Orion chargers can be paralleled/stacked for higher output.

 

[Alloy]

Some inverters are grounded internally. If so the circuits should be grounded.

A breaker will protect the wire. To protect people it is best to use a dual function GFCI/AFCI breaker or receptacle

Leviton 15 Amp 125-Volt Duplex Self-Test SmartlockPro Tamper Resistant AFCI/GFCI Dual Function Outlet, White-R92-AGTR1-0KW - The Home Depot

Today more than ever homes are equipped with important electrical safety devices to help protect people and property. Most prominent are the GFCI Receptacle, which helps protect people from shock or electrocution

www.homedepot.com

I've read about people using juice packs ro run CPAP for 2-3 days

 

[rayra]

have to ask the OP if the solenoid is remaining switched on in his wiring setup, when the key / engine is off. That's the only condition where his starter battery ought to be getting drained by 'house' usage / draw.
And the solenoid / combiner should in no way be interfering with the vehicle's factory charging system. Key on, solenoid on, batteries combined, they'll be trying to reach an equivalent potential and appear that way to your stock charging system. And as long as that's lower that your charging system is set to charge to, you'll get charged.

I'm running the keyed-on combiner solenoid setup and not having any sort of problem getting a fully charge on both batteries durign long driving and isolated usage when the vehicle is parked.
But I'm also using identical batteries for other reasons, not a deep cycle as house. I'm also using a fat 1/0 cable to the rear of me vehicle from my Aux to a cargo area box that has most of inverter usage. As well as my rooftop solar feeding there / backfeeding the Aux thru that 1/0 cable.

 

[mep1811]

Does anyone know if two of these could be used simultaneously? They are a good price compared to other DC-DC chargers I've been seeing but I think I could use more than 10 amps for my 215ah battery bank.

I've had the TOAD charge up my 100 amp battery in a days driving (8hrs) . Are you letting your 215 amp battery get that low? Then maybe setting up an actual dual battery setup with the trailer batteries being directly charged via the vehicle alternator would be better .

 

[Buddha.]

I've had the TOAD charge up my 100 amp battery in a days driving (8hrs) . Are you letting your 215 amp battery get that low? Then maybe setting up an actual dual battery setup with the trailer batteries being directly charged via the vehicle alternator would be better .

I haven't been because I had the generator in the back of the truck. We don't really use much 120v though so I'm trying to figure out how to leave the 180lb generator at home.

 

[shade]

This appliance has ability to increase output voltage above its input voltage.
Its better suited adjacent to trailer batteries. Resistance of supply conductors will less affect output voltage ultimately reaching your trailer battery.

@Buddha.

Yep. The manual indicates the Orion isn't designed for a harsh environment, like an engine bay.

The genuinedealz link I posted earlier goes to a voltage drop calculator. Copper 2AWG has a voltage drop of 2.4% over 30', iirc. Even with a few (good) connectors thrown in, that should be plenty good for small tow vehicle + trailer combos. Shorter runs would have less drop, and might be ok with lighter cable.

 

[Buddha.]

I’m having a hard time wrapping my head around the concept.
I can
A:
Run a couple 0 or 2 gauge wire all the way back with a Anderson power pole connection at the trailer but then I have to take into account that my truck’s charging system and my charge wires need to get a sufficient voltage back to the trailer.

B:
Buy an expensive dc-dc charger to solve the voltage problem but then my charge wires still need to be relatively heavy gauge anyway.?

I have a volt meter plugged into my cig lighter and see my voltage is never lower than 14v usually 14.2-14.4, I’ve seen it as high as 15.2 after pulling into my parking spot at work while letting it idle for a couple min. Seems odd to me that the highest voltage I see is while the engine is at idle.
I might just run the heavy wires back with no dc-dc charger, not sure I need it.
Planning on ~400w solar too so I don’t have to idle the truck forever to top off the batteries.

 

[shade]

I’m having a hard time wrapping my head around the concept.
I can
A:
Run a couple 0 or 2 gauge wire all the way back with a Anderson power pole connection at the trailer but then I have to take into account that my truck’s charging system and my charge wires need to get a sufficient voltage back to the trailer.

B:
Buy an expensive dc-dc charger to solve the voltage problem but then my charge wires still need to be relatively heavy gauge anyway.?

I have a volt meter plugged into my cig lighter and see my voltage is never lower than 14v usually 14.2-14.4, I’ve seen it as high as 15.2 after pulling into my parking spot at work while letting it idle for a couple min. Seems odd to me that the highest voltage I see is while the engine is at idle.
I might just run the heavy wires back with no dc-dc charger, not sure I need it.
Planning on ~400w solar too.

• Determine where you'll mount a DC-DC charger - likely inside the trailer.
• Use some string to find the length of cable run from the engine bay to the DC-DC charger.
• Use a voltage drop calculator to determine a sufficient wire gauge - it could be lighter than 2AWG, but you can't go wrong with that, either.

If you opt not to use a DC-DC charger, you'll have to be more concerned with voltage drop, which will probably mean running heavier wire (2AWG will probably be fine). Without sufficient voltage at the trailer battery, it won't accept much of a charge. Without a DC-DC charger, you won't have any control of the charge current or voltage, which may not be as important to someone using a lead battery compared to a lithium-based chemistry.

You'll probably still want a shore power charging option so you can make sure a lead trailer battery is taken up to 100% state of charge regularly.

 

[john61ct]

The DCDC charger, mounted at the target bank, will accept a fair voltage drop no problem.

 

[luthj]

What voltage does your alternator produce? That's the starting point. From there you can determine if its reasonable to get charging to your trailer. For example, if your alt produces 13.9V nominal, its not going to charge well, even if the battery is right next to the alternator. Add a few tenths of a volt drop in the wiring, and charging is going to be anemic at best.

If your alternator is outputting 14.5V, then you have a good chance. If you can get 14.1-14.2V at the battery, you will have decent charge rates. So lets assume you can tolerate a 0.4V drop in this scenario. That is 0.2/14.5=2.75%. Choose a reasonable current, say, 20A, and find the wiring that results in less than 2.75% drop. Remember that connections and fuses will add some to the voltage drop.

The DC-DC chargers are more flexible. Look at their specs. Whats the minimum input voltage? If its say 12.5V (with an external ignition trigger/control), then you are at 2/14.5 = 13.75% drop allowed.

In addition, because the DC-DC boosts the voltage, if your alternator is on the low end voltage wise, the DC-DC will allow higher charge rates than normally possible, even with a long wire run.