I want to charge my camper with the truck's alternator. Isolator / Relay?

[Costman13]

Hello all,

I am very new to truck campers and a bit electronic illiterate. I have a new to me 2003 FWC Eagle and would like to be able to charge / maintain the house battery with the trucks alternator. I know that stock alternators were not designed to charge multiple batteries especially those which are 15 feet away. However, If all it did was maintain the house battery, and on extended trips slowly charge, that is better than what I have going on now. While cruising the internet I found a million complex ways to do this. Is there any reason as to why you could not use a simple battery isolation switch and a charge relay, like you would on a boat?

For example: http://www.amazon.com/Blue-Sea-Systems-120A-Add-A-Battery/dp/B000RZNP5K/ref=cm_cd_al_qh_dp_i

Any ideas are greatly appreciated.

Thank you,

Cameron.

 

[subterran]

Hello, see my last post in my build thread. Maybe it will help you:
http://www.expeditionportal.com/for...-Woodsy-Bit-Adventures-of-an-88-Phoenix/page4

 

[fisher205]

Everything you need to know here. http://www.expeditionportal.com/for...ke-a-cheap-isolated-dual-battery-setup-for-50

 

[1stDeuce]

I tried this for a while. There are ways it can be done, described well in links above. You mostly just want a relay to keep from draining the truck battery when you stop. The key to getting a good charge from the truck is using 10ga or better wire and keeping the run short. BUT... if you're not driving EVERY day, you'll end up running your battery down more than it will appreciate. For a fairly small cash outlay, you could never have to worry again if you go with a solar charge setup. Even if it's only a 50W panel, you'll be so much better off. You can still tie to the truck battery if you want, you just don't have to, and you don't have to run the truck to charge the battery (Which takes a LOT longer than you'd think...) ever again!
Good luck!

 

[Costman13]

Thank you for the replies! I have no need to connect the two batteries, for a full dual battery setup. I plan on adding a small solar set up one day, but for now it I would like to just maintain the current house battery. I am not looking to charge it per-say, but just maintain a charge, mostly due to my 3way fridge. Driving down the road in the DC operation consumes a ton of battery life. I always plug in the camper prior to and upon return of a trip to ensure I start / end with a full battery charge.

I was planning on running a large AWG to the bed mostly because of current drop. Does 4 AWG sound about right? Too big? Too small? It is not traveling too far, just to the front of the bed on the passenger side of a 2002 Ext. Cab. And connecting the truck side to the camper side with these: http://www.summitracing.com/parts/aaf-all76322/overview/

 

[pappawheely]

This will handle all your needs and it's a smoking deal!

http://www.techbatterysolutions.com/CTEK-D250S-Dual-Battery-Charger-p/c008.htm

 

[subterran]

If I understand you correctly, you could be about to make a mistake that will strand you at camp. If you simply run a pair of fat wires from your starter battery to your camper battery (please please put a fuse in it) then you can expect 2 dead batteries, WHEN you forget to disconnect them when you get to camp. Or maybe even if you do disconnect them. Here's why: You've been parked for a few days. Your fridge has been running on propane, but your water pump, lights, etc, have been draining your camper battery. When you hook up the battery-to-battery leads, Your camper battery is going to suck all of the voltage out of your starter battery, and your truck won't start. If you were to connect directly to the alternator, that wouldnt be a problem, but I have no idea what the long-term ramifications of that might be. You really need to strongly consider an isolator relay of some sort if you are going to connect the two systems together and travel that way, or you're asking to be stranded. Good luck!

 

[Costman13]

If I understand you correctly, you could be about to make a mistake that will strand you at camp. If you simply run a pair of fat wires from your starter battery to your camper battery (please please put a fuse in it) then you can expect 2 dead batteries, WHEN you forget to disconnect them when you get to camp. Or maybe even if you do disconnect them. Here's why: You've been parked for a few days. Your fridge has been running on propane, but your water pump, lights, etc, have been draining your camper battery. When you hook up the battery-to-battery leads, Your camper battery is going to suck all of the voltage out of your starter battery, and your truck won't start. If you were to connect directly to the alternator, that wouldnt be a problem, but I have no idea what the long-term ramifications of that might be. You really need to strongly consider an isolator relay of some sort if you are going to connect the two systems together and travel that way, or you're asking to be stranded. Good luck!

Not what I was thinking. There would be a charge solenoid between the two batteries. All fused up and all that jazz, no worries there. I will put a switch on the truck side, to ensure the wires to the camper are cold when not in use. The solenoid will be in the camper. I WILL NOT be directly connecting the camper house battery and the truck battery. It will have a solenoid like this controlling the voltage / charge. http://www.amazon.com/Blue-Sea-Systems-120A-Add-A-Battery/dp/B000RZNP5K/ref=cm_cd_al_qh_dp_i

 

[subterran]

OK, good deal. One last thing: On big fuses of 30 amps or larger - they make a scary, nasty pop when they go. Just be aware. Be safe, and be redundant!

 

[Stan@FourWheel]

Costman

Feel free to call or email me.

I can better explain, walk you throught it, and email you the wiring instructions if you want.

Welcome to the FWC family.



Stan

 

[gsanders]

I recently purchased a camper and for the time being I just tie into the trailer plug, if your plug has an always hot connection (6 or 7 pin plug). Yes, it is not the best, but for the time being it works. My camper came with a plug that was setup to hook into the trailer plug so it works for me. I just always remember to unplug it at camp. However, the connection is right below where I attach my stairs so I can't really miss it. I have checked the voltage while the truck is on and at my alternator I get around 14.2 V and at the camper batter it is 13.5 V, so yes it is charging but it is slow. I only use this setup for long travelling days to allow my fridge to run on 12V and maintain the batteries. I recharge by batteries after a trip when I get home using NOCO Genius 7200 which is great: http://www.geniuschargers.com/G7200. I also plan on installing solar but for the time being this system works and hasn't failed me. If your truck has a trailer plug it is one easy and cheap method to consider.

 

[Costman13]

Costman

Feel free to call or email me.

I can better explain, walk you throught it, and email you the wiring instructions if you want.

Welcome to the FWC family.



Stan

Thanks Stan, that would be great! Do you have a preferred email address?

Thank you,
Cameron

 

[Stan@FourWheel]

Stan@fourwh.com

 

[Scoutman]

I recently purchased a camper and for the time being I just tie into the trailer plug, if your plug has an always hot connection (6 or 7 pin plug). Yes, it is not the best, but for the time being it works. My camper came with a plug that was setup to hook into the trailer plug so it works for me. I just always remember to unplug it at camp. However, the connection is right below where I attach my stairs so I can't really miss it. I have checked the voltage while the truck is on and at my alternator I get around 14.2 V and at the camper batter it is 13.5 V, so yes it is charging but it is slow. I only use this setup for long travelling days to allow my fridge to run on 12V and maintain the batteries. I recharge by batteries after a trip when I get home using NOCO Genius 7200 which is great: http://www.geniuschargers.com/G7200. I also plan on installing solar but for the time being this system works and hasn't failed me. If your truck has a trailer plug it is one easy and cheap method to consider.

That 120v smart charger looks very similar to the CTEC7002 that I was looking at getting. I currently use the 7 pin trailer plug on my truck to charge my batteries but am looking for a better system since anything that is running is also running off my truck battery (for example, when I'm at work waiting to hit the road and the fridge is running).

 

[kerry]

On my Fuso, I just used a relay, activated by a wire energized only when the ignition switch is on. Works fine. However, I don't run the frig on 12 volts. I have a Northstar camper with a pretty big frig. When I went to run it on 12 volts I discovered the wiring wasn't connected. I called Northstar. They told me that it was not connected deliberately. A frig that big has too large a draw for the battery in their opinion. They said just run it on propane when going down the road.