30 replies to this topic

[ntsqd]

Theoretically you can work the ampacity formula with X/12ths of a foot and get just how many amps a 4" long piece of 10ga. wire can handle. It's impressively high.

 

Practically I think that unwise unless there are very compelling and unusual circumstances. Run the same gauge wire cable as elsewhere in the circuit.

 

In the old camper I did the same as Vic, breakers mounted as close to each battery bank (truck and camper banks) as was reasonably possible. Solar connected directly to the battery. I placed the old camper's breaker in the circuit such that if you turned it off and either disconnected the Anderson connector or turned off the truck breaker then the whole camper was electrically dead.

I've yet to do the camper end of the new to us camper. Access to the backside of the outside accessible battery box is severely difficult and I've not yet worked out exactly how I'm going to do what needs to be done for the install to be safe. I did install a Blue Sea Systems 150A battery terminal fuse right at the battery + terminal just in case the less than ideal OEM wiring develops a short. Due to necessary distance from the batteries I'll likely leave that in place once I install the breaker.

[Vic Harder]

Thanks for the reply Vic.

 

Maybe I am not understanding or missing the big picture here.

 

I was going to upgrade the wiring from truck to plug in (was going to do the Anderson plug that others have mentioned) with 6ga....

 

I'm not sure of the alternator on my truck, it is a stock 2014 Ford F150.  

 

My current setup is completely off the FWC Kit

-30 amp breaker (mounted under hood)

-10 ga wiring

-Anderson trolling motor connection

 

For Solar I have 

Victron 75/15 controller

Renogy 160 watt panel

 

Everything in the camper is wired with 10ga.

 

Best,

 

Luke

Luke,  I'm not sure if you are asking a question here?

[Utah]

Reading through this thread with interest - getting me motivated to also upgrade my wiring from truck battery to camper.  I have acquired a 2015 Hawk shell that is installed on a Chevy Silverado 1500 (with tow package) by FWC factory dealer when originally purchased by previous owner.  It currently has 10ga wiring to camper.

 

If I run a calculator for voltage drop with 6 ga wiring it returns voltage drop of 1.18 volts at 60 amps for 25 ft. run.  However, I do not have a way of measuring amperage output of the truck alternator in my system.  Do you think 6 ga wire is adequate?  I am currently charging two house batteries in camper from the truck when on the road.  My future plan (this year) is to also add solar panel and Victron charging controller.  Still trying to get educated on the electrical upgrades I want to do.

 

Thanks for any comments.

 

Pieter

[Ruck_and_Roll]

Sorry Vic,

I think my ramblings are probably confusing.  I was thinking aloud if "am I going to fry my system and start my camper on fire."  It looks like I need to a little more research.  I think I need a better grasp of the overall electrical components I have installed (or are preinstalled). 

 

I may start out the project by just replacing the surepower 1314 with the ACR, see what I get for charging with the 10ga stock setup.  If insufficient, may do the 6ga upgrade with the new breakers, and upgrading the wiring from 10ga to 6ga, both inside the camper and out.

 

Best,

 

Luke

[Vic Harder]

Reading through this thread with interest - getting me motivated to also upgrade my wiring from truck battery to camper.  I have acquired a 2015 Hawk shell that is installed on a Chevy Silverado 1500 (with tow package) by FWC factory dealer when originally purchased by previous owner.  It currently has 10ga wiring to camper.

 

If I run a calculator for voltage drop with 6 ga wiring it returns voltage drop of 1.18 volts at 60 amps for 25 ft. run.  However, I do not have a way of measuring amperage output of the truck alternator in my system.  Do you think 6 ga wire is adequate?  I am currently charging two house batteries in camper from the truck when on the road.  My future plan (this year) is to also add solar panel and Victron charging controller.  Still trying to get educated on the electrical upgrades I want to do.

 

Thanks for any comments.

 

Pieter

Pieter,  two batteries, so likely 150AH or more combined?  I suspect your 2015 has a lot "smarter" alternator than my 2006, which is not a good thing in this case, as the "smart" alternators are actually much better for your truck battery, not so good for a camper battery 25' away.

 

My alternator sits at about 14.4v normally, and I've seen 90A go across the wires to the camper.  The voltage at the camper battery needs to be about 0.5v higher than the battery is currently at in order for charging to happen.  Meaning that if your camper battery is at 12.5v, 13.0v needs to arrive at the camper battery AFTER the voltage has dropped.  Using your 6g and 60A example, that would mean your alternator needs to put out 13+1.18v = 14.2v or so.  

 

Do you have a voltmeter?  Or a real gauge in the truck so see what the voltage is at cruise?  If you can't get 14.2v or more, then you either need thicker wires or a DC/DC charger.

[Vic Harder]

Sorry Vic,

I think my ramblings are probably confusing.  I was thinking aloud if "am I going to fry my system and start my camper on fire."  It looks like I need to a little more research.  I think I need a better grasp of the overall electrical components I have installed (or are preinstalled). 

 

I may start out the project by just replacing the surepower 1314 with the ACR, see what I get for charging with the 10ga stock setup.  If insufficient, may do the 6ga upgrade with the new breakers, and upgrading the wiring from 10ga to 6ga, both inside the camper and out.

 

Best,

 

Luke

That is an excellent plan.  If you get the Blue Sea ACR with the remote switch, you can lock the relay into connected mode to maximize charging even if the voltage drops too much.

 

Fire is unlikely given what we have been talking about so far.  Still, it is very appropriate to be cautious.

[ntsqd]

R&R, Are there breakers or fuses at both ends of the truck to camper connection? There needs to be regardless of the wire size.

[Utah]

Vic - your posts are a great resource.  Thanks.

 

My truck is a 2011 Chevy Silverado.  It has regulated voltage control.  I can keep it in charging mode with the tow/haul button.  I believe the generator output voltage in charging mode is 13.9 to 15.5 V.  (It does seem to vary).  When driving I prefer to just be in economy mode much of the time where the generator output voltage drops to 12.6 to 13.1 V.  This leaves me always concerned about whether the camper batteries are fully charged when arriving to camp site.

 

Right now I have two AGM batteries in the camper that were installed in January 2016 (previous owner).  I do not have a battery monitor installed yet (another upgrade project).  The advertised capacity of each battery is 84 Ah when new.  When these need to be replaced, I will probably be looking into LiFePO4 batteries.

 

I could increase the wire size to 4ga or 2ga, However, I will always be dealing with variable voltage output by the truck.  Also, I assume that running thicker wire adds complication for running the wires and with the disconnect.

 

It seems that the preferred solution for me is indeed installing a DC/DC charger:

 - Do you think it still worth upgrading the stock 10ga wire from the truck to 6ga?

 - Is there a recommended DC/DC charger that will also function as solar charger/controller (solar will be another upgrade)?

 - If I install a DC/DC charger now for charging the AGM camper batteries, will it be suitable for charging future LiFePO4 batteries?

 

Thanks

[PaulT]

I have no personal experience with their product but I have spoken to one person using a Redarc battery booster/charger with built in MPPT solar charge controller on his pair of LiFePO4 Battleborn batteries. He was very pleased with the unit. 
https://www.etrailer...-BCDC1240D.html

Perhaps, another WTW member has experience with the unit.

Paul

[Vic Harder]

Right now I have two AGM batteries in the camper that were installed in January 2016 (previous owner).  I do not have a battery monitor installed yet (another upgrade project).  The advertised capacity of each battery is 84 Ah when new.  When these need to be replaced, I will probably be looking into LiFePO4 batteries.

 

I could increase the wire size to 4ga or 2ga, However, I will always be dealing with variable voltage output by the truck.  Also, I assume that running thicker wire adds complication for running the wires and with the disconnect.

 

It seems that the preferred solution for me is indeed installing a DC/DC charger:

 - Do you think it still worth upgrading the stock 10ga wire from the truck to 6ga?

 - Is there a recommended DC/DC charger that will also function as solar charger/controller (solar will be another upgrade)?

 - If I install a DC/DC charger now for charging the AGM camper batteries, will it be suitable for charging future LiFePO4 batteries?

 

What Paul says below is great.  That RedArc unit looks great.  I have a Renogy for sale right now because I decided that it was more important to me to have the solar panels charge the truck at all times, and the Renogy is a one way solution.

 

I would try the 10g first before upgrading.  You might want to upgrade to thicker than 6g after you have more data.  Getting that monitor installed first might be a good idea.

 

The DC/DC charger should have settings for the type of battery it is charging, so AMG/FLA/LiFePo options are possible.

 

With my current build, I have 200AH of LiFePo4, and 2g wires with a ML7622 ACR.  I can monitor voltages at the alternator and at the camper batteries.  I tend to use the alternator for bulk charging only, and then disconnect so that the solar panel and Victron MPPT controller can do the final tweeking.