Wire Routing

[RamVenture]

Hello gentlemen, I purchased an ecoflow power station and alternator charger. The charger will allow me to charge my power station using the trucks battery/alternator. The charger can charge up to 800wattts or roughly 61amps. The kit looks well-built and includes heavy duty gauge wires. My truck is a 2012 2500. The question I have is getting the cables routed into the cab. The wires are too thick to go through the firewall.

My plan is to mount the charger under the driver seat or under the rear passenger seat. I noticed two sets of plastic plugs under the seats. It seems I would need to remove the front seat to get access to the plug underneath so I'm leaning to placing the charger under the back seat. In the back, does anyone know one of the plugs connects directly into the under-seat storage compartment? Can I drill directly through the center of the plug?

Now with regard to the battery connection, I would prefer to connect to the driver's side battery. Having replaced the batteries twice now, it has always been a bear replacing the passenger's side battery and I would prefer to not add more wires to deal with later. Also, the turbo is on that side and thinking maybe that side gets hotter. That said the alternator is on that side so direct connect to the battery/truck alternator connection point. Is it necessary to connect on the passenger side battery? With regard to the ground connection. Any issue connecting to a ground point on the frame vs at the battery? I have attached a pdf with some pictures. Thanks for the help!

 

[lpennock]

Main advantage to connecting to the passenger battery is you get rid of any losses due to the cross over cable. If your cross over cable starts to develop high resistance you will get a large voltage differential between the two batteries if your connected to the driver battery which will cause the computer to over charge the passenger battery. When you connect to the passenger battery there is less current through the crossover cable so the voltage on both batteries stay closer so less chance of over charging.

As far as connecting ground to the frame there isn't an issue with doing that as long a you have a large enough lead from the battery to ground to handle the maximum current the system needs. You will probably need to up size your batter to ground lead if you do that.

 

[Ozymandias]

ECM measures from the driver side battery, you want to connect a heavy load there otherwise the ECM could raise the charge voltage to levels you don't want.

 

[lpennock]

ECM measures from the driver side battery, you want to connect a heavy load there otherwise the ECM could raise the charge voltage to levels you don't want.

Beg to disagree. You are correct about measuring on driver side and charging on passenger side. Connecting to drivers side puts the voltage drop of the cross over cable in the circuit which causes higher voltage on the passenger battery. I.E overcharging of passenger battery. When you connect to passenger side you don't have as much current through the cross over cable so less voltage drop which puts the voltage on both batteries closer so regulation works correctly.

 

[Ozymandias]

I'm not so sure about this, you pull huge amounts right from the Alternator which pulls the grid down, RCM wants to compensate for this until it sees the desired voltage at battery the drivers side.
Passenger could be much higher then.

And, a weak cross-over cable should be fixed anyways, no?

 

[Topzide]

I know that the ground connections that are listed in my wiring manual, say that 50A max draw. If you are wanting to ground to the frame, I'd have a ground lead from the battery that is at least the min amp draw to that connection point, but if having to that, why not just connect directly to the battery! Less of a chance of a low power issue to your charger. Appropriate type of wire is made to handle the heat or sleeve it with the correct shielding.

 

[lpennock]

I'm not so sure about this, you pull huge amounts right from the Alternator which pulls the grid down, RCM wants to compensate for this until it sees the desired voltage at battery the drivers side.
Passenger could be much higher then.

And, a weak cross-over cable should be fixed anyways, no?

Agree that bad crossovet should be fixed but resistance builds up over time so things happen. There are numerous people that the first indication they notice of the Xover cable being bad is when the passenger battery boils out or explodes from being over charged at 16+V.

So lets do some math. Looking at an ideal Xover 6ft cable of 1/0 guage. If you are pulling a constant 65amps (55a for the inverter 10A for the truck operation) across the cable you will have a voltage drop of just under 0.1v. Which is close enough it won't matter. But if the connections gets corroded so the cable looks more like a 6 guage the voltage drop rises to about 0.4V. At 0.4V you are starting to do damage to the passenger side battery because of the voltage difference. Take that same 6 guage resistance but drop the current to 10A and the voltage drop goes to 0.06 V. So both sides will be at essentially the same voltage and the charging will be working correctly.

So with a ideal new Xover cable it doesn't matter which battery you connect too. But as resistance builds up over time connecting to the passenger battery will make the system less sensitive to the current draw of the inverter.

 

[RamVenture]

Sounds like I should just connect the terminals to the passenger battery posts. I've always wonder why when jumping a car, the instructions say to connect to the frame. I've usually just connected to the battery posts. Not really sure what the difference was. Thanks for the advice.

 

[petersonj]

I've always wonder why when jumping a car, the instructions say to connect to the frame. I've usually just connected to the battery posts. Not really sure what the difference was.

This is more about safety than anything else. Usually, when a vehicle is being jump started, it is unknown to the good Samaritan what the condition of the discharged battery is in. It is very likely that hydrogen gas will be present around the discharged battery. A serious explosion can result if the hydrogen gas is ignited.

When the last of the four connections are made with the jumper cables, there will almost always be a spark when the connection is made. This is why the last connection should be a ground connection made well away from the battery at either the vehicle frame, or the engine block.

- John

 

[Ozymandias]

By the way I connected the ground wire for the Camper to the engine block itself instead of an already cramped battery post.
And it is the best ground you can find on the vehicle, better then any other place.