Upgrading Wiring to Charge Camper Batteries From Truck?

[pvstoy]

At some point in time a battery replacement will be required. You'll have a opuntunity to upgrade to new technology or keep it simple as it is working. You have been keeping good care of that yellow top to last that long. I feel the newer blue and yellow tops are not the same as the older ones were. Take your time and maybe embrace new technology to the point you don't get dizzy

PV, thanks. You are correct, I did upgrade my alternator. I will probably be buried in my Camper! I love my 1986 Toyota Turbo pickup/ Ranger II!
.......

.....My battery is old and I was thinking about replacing it with a bigger one. Maybe even a lithium to save weight, but I don't want to get into all of the extra stuff.

 

[Beach]

On my 06 tundra I wired the camper 12v pos straight to the truck battery through a Bluesea 40 amp breaker mounted under the hood that I manually closed when I needed to charge the camper battery. System worked fine until the day I retired the Tundra from camper. So if you want simple, it will work just fine.I highly recommend you mount a digital volt meter to monitor the battery voltage though.

 

[So Cal Adventurer]

If I understand your original post, you have questions about how the wiring inside your cabinet, from your isolator inward to your camper batteries, is routed.

I have the same questions. Without pulling the cabinet apart it would be nice to know, generally, how things are routed in there.

Exactly!!

 

[muttmaster]

Advise needed on inside wiring. I have hooked up 2 gauge from truck battery to camper bed ending with Anderson plug. Now I am finally ready to finish the connection inside the camper, but need some advise.
I am finally trying to finish my wiring upgrade because I discovered how inefficient the 10 gauge from the truck was charging up my camper battery. I thought I never needed to finish the 2 gauge upgrade as my two solar panels was more than satisfactory...until one of them died on trip to the desert, with my new compressor cooler drawing a bit more juice than I had anticipated.

My dilemma after looking inside is... should I continue with 2 gauge to the isolator? How do I use such large lug needed in 2 gauge to connect to negative bus bar and the isolator? And should I upgrade the battery connector wiring too to 2 gauge? It looks like 8 gauge was used to serial connect the two AGM.

Can I step down to 4 or 6 gauge from camper isolator and neg bus to outside camper with Anderson plug that can connect to the big A plug 2 gauge from truck? Do they make a step up or down A plug from 2 gauge to 4 or 6?

Also, since I have both 10 gauge hooked up right now to Trolling motor plug with three wires and the 2 gauge with A plug to camper bed already. Can I still keep the 10 gauge connection once the upgraded wiring is somehow installed inside. The reason I am not sure if Taking out the existing wiring will affect any thing else as the blue/ green wire just before the isolator is tapped into for water tank sensors? It looks like it was heading down that away.
Thanks for any input.

 

[klahanie]

muttmaster, there are some reducing bushings avail for the A powerpole contacts
Anderson Power Products Powerpole Reducing Bushings

or what I have done is use the matching plug and contact and on the reduced wire side folded to small ga wire over and/or filled the space with wire strands. This I've done when soldering rather than crimping.

For lugs, there are often a few sizes made for different stud sizes.
Tinned Copper Cable Lugs

I don't claim to fully understand your system but I would prob run the heavier ga completely from truck battery/alternator to house batts. With the same ga inter connecting the house batteries if there are more than one.

HTH

 

[muttmaster]

Thanks HTH for the links. My system is the stock 2016 Grandby side dinette. I have folded over the smaller gauge wire ends to fit into larger Anderson plug tangs to mate with larger gauge A plug in the past with smaller gauge cables. I may give that a try as I already have a A plug to mate with the 2 gauge from the truck. Maybe fold over the ends of 6 gauge to solder and crimp into the larger A plug tangs. That way I may find 1/4 lug ends to fit onto the 1/4” attachment bolt on the bus bar and the isolator. Or maybe install a breaker inside as many have suggested and in coming side still using 2 gauge and the other side reduced to 4 or 6 gauge.

 

[So Cal Adventurer]

Well, for starters, if you go to the Blue Sea website, and read the instructions for wiring the ACR, it literally says right in the instructions it should be wired with 2awg. So theres that.

Ill post what i did and my results in a few.

 

[So Cal Adventurer]

Thanks HTH for the links. My system is the stock 2016 Grandby side dinette. I have folded over the smaller gauge wire ends to fit into larger Anderson plug tangs to mate with larger gauge A plug in the past with smaller gauge cables. I may give that a try as I already have a A plug to mate with the 2 gauge from the truck. Maybe fold over the ends of 6 gauge to solder and crimp into the larger A plug tangs. That way I may find 1/4 lug ends to fit onto the 1/4” attachment bolt on the bus bar and the isolator. Or maybe install a breaker inside as many have suggested and in coming side still using 2 gauge and the other side reduced to 4 or 6 gauge.

Easier, safer, and more secure to just make new cables, its fairly easy and everything will fit and look better

 

[ntsqd]

It goes against convention, but the way that I see it is each cable is its own conductor with its own inherent Voltage Drop. Say that you bring 2ga. to the ACR/VCR that is 1 foot (of cable) from the battery(ies) and that is good for 100A at less than 3% Voltage Drop to that point. How big does a 1 foot long jumper cable have to be to conduct 100A at less than 3% Voltage Drop? It does not need to be 2ga., though it can be.

I contend that for short jumpers you can go smaller than what is needed in the whole circuit. It complicates the calculation, but can simplify the install.
This concept falls apart if you attempt to use a sequence of isolated studs with short jumpers between each as an attempt to use (& justify) a smaller wire size for the whole circuit, but for a single or just a couple short jumpers I see no fault in the logic. I'm quite sure that there are those who will disagree with this and insist on using the same large gauge in the whole circuit. That is fine and it certainly the easiest way, especially when trying to help someone who is "electrically challenged."

 

[muttmaster]

Thanks all for suggestions. My other question was whether I should keep the 10 gauge connection via trolling motor connector and just use the 2 gauge via Anderson plug just when I really need a boost from the truck. Got new solar panel coming and it always was never a issue until I got a new compressor fridge that uses more juice than I had hoped and the older semi flex panel died and my 3 way camper fridge not cooling due to oil plugged propane controller.... all on same trip In DV at that.

Now on quest to do it right and be prepared.

 

[So Cal Adventurer]

Thanks all for suggestions. My other question was whether I should keep the 10 gauge connection via trolling motor connector and just use the 2 gauge via Anderson plug just when I really need a boost from the truck. Got new solar panel coming and it always was never a issue until I got a new compressor fridge that uses more juice than I had hoped and the older semi flex panel died and my 3 way camper fridge not cooling due to oil plugged propane controller.... all on same trip In DV at that.

Now on quest to do it right and be prepared.

Ditch the trolling motor connector completely

 

[So Cal Adventurer]

Ok...

Here’s my results from my recent upgrade...

Usually had plenty of charging with solar but after a recent stretch of 5 days of non stop rain, the batteries wouldn’t charge enough while driving.

Ran some tests...

2014 Tundra 5.7L with factory 130amp alternator

As wired from FWC with the trolling motor plug and 10 gauge wire with the camper batteries down to 70% SOC, I was only getting 9-10amps to them from the alternator at idle.

Rewired ALL of it with 2awg and now when batteries down to 70% SOC, I’m getting 42-43 amps at idle.

Also worth noting, I ran a 2awg ground from the camper negative just bar directly to the truck frame as well

Almost 5 times the charging power.

Just a heads up for those looking to charge faster while driving.

 

[muttmaster]

Good to know. My thinking on keeping the 10 gauge connection is that it does give some charging on long drives and if I only switch in the 2 gauge connection when I really need the boost if I had to idle the truck for a bit to prevent house batteries going too low if solar fails again or when it is cloudy for few days.

Chances of raining days straight is very low where I am. But I was wondering what harm is it to keep the 10 gauge connection, which is there and I assume working while the 2 gauge connection will be switch on/off manually as needed, if rarely. With 260 watts solar on the roof and 100 watts suitcase if needed. Charging from truck is a backup for my backup panel.

Maybe I worry too much and have too many questions in my electrically challenged mind.

 

[So Cal Adventurer]

Good to know. My thinking on keeping the 10 gauge connection is that it does give some charging on long drives and if I only switch in the 2 gauge connection when I really need the boost if I had to idle the truck for a bit to prevent house batteries going too low if solar fails again or when it is cloudy for few days.

Chances of raining days straight is very low where I am. But I was wondering what harm is it to keep the 10 gauge connection, which is there and I assume working while the 2 gauge connection will be switch on/off manually as needed, if rarely. With 260 watts solar on the roof and 100 watts suitcase if needed. Charging from truck is a backup for my backup panel.

Maybe I worry too much and have too many questions in my electrically challenged mind.

I’m no expert either but keeping 2 separate systems sounds complicated as hell

 

[muttmaster]

I am not sure it is that complicated, after all both 2 gauge and the factory 10 gauge goes to the same negative bus and the positive goes to the Blue Sea isolator. It is essentially on one system. I am thinking maybe I need to shut off the 10 gauge line if and when I need to switch in the 2 gauge side. I may be able to leave both on but that may confuse the isolator? Maybe a question for Blue Sea tech to answer. I have called them before long time ago and they were very helpful.

I could test it myself once I finish upgrading but was hoping someone else here have done the same already and knows the advantages and perils of having dual connections from the truck.

 

[klahanie]

Here’s my results from my recent upgrade...

Well good for you, but sux for the aftermarket biz....

 

[So Cal Adventurer]

Well good for you, but sux for the aftermarket biz....

Why’s that?

 

[klahanie]

Why’s that?

Pardon my mistake. I erred in posting.

As for my remark, it was based entirely on assumptions. First, that the large improvement you report was both welcome and beneficial to you (a sincere, "Well good for you,...).

Second, that such an alteration may make unnecessary, and perhaps is an alternative to, some charging products offered for sale by the aftermarkets such as HO alternators and B2B chargers ("but sux for the aftermarket biz....).

Third, that my second assumption could be supported by the comment, "Just a heads up for those looking to charge faster while driving."

No offense was intended.

Well good for you, but sux for the aftermarket biz....

Ok...

Here’s my results from my recent upgrade...

Usually had plenty of charging with solar but after a recent stretch of 5 days of non stop rain, the batteries wouldn’t charge enough while driving.

Ran some tests...

2014 Tundra 5.7L with factory 130amp alternator

As wired from FWC with the trolling motor plug and 10 gauge wire with the camper batteries down to 70% SOC, I was only getting 9-10amps to them from the alternator at idle.

Rewired ALL of it with 2awg and now when batteries down to 70% SOC, I’m getting 42-43 amps at idle.

Also worth noting, I ran a 2awg ground from the camper negative just bar directly to the truck frame as well

Almost 5 times the charging power.

Just a heads up for those looking to charge faster while driving.

 

[Vic Harder]

Ok...

Here’s my results from my recent upgrade...

Usually had plenty of charging with solar but after a recent stretch of 5 days of non stop rain, the batteries wouldn’t charge enough while driving.

Ran some tests...

2014 Tundra 5.7L with factory 130amp alternator

As wired from FWC with the trolling motor plug and 10 gauge wire with the camper batteries down to 70% SOC, I was only getting 9-10amps to them from the alternator at idle.

Rewired ALL of it with 2awg and now when batteries down to 70% SOC, I’m getting 42-43 amps at idle.

Also worth noting, I ran a 2awg ground from the camper negative just bar directly to the truck frame as well

Almost 5 times the charging power.

Just a heads up for those looking to charge faster while driving.

Great news!

I'd ditch the pre-exisiting 10g wiring. I'm thinking of ground loops, dangerous currents being pushed through the 10g if one of the 2g connections fails, etc.

Your experience with much better current being sent over 2g reflects the Tundra (and other ECU controlled alternators) that have "low" output voltages compared to non-ECU (aka older) alternators. The low starting voltage makes the voltage drop over the 10g wire significant enough that it can't move very much current. With a bigger pipe, the voltage drop is less and you get way more juice.

 

[muttmaster]

Ah, the more juice guru chimes in... that settles that. Thanks Vic. I was wondering about ground loops and too much juice...ditching the 10 gauge.

I wonder why 4WC didn’t follow Blue Sea’ specs in wire gauge install. BS Manual states 6 gauge if over 10’ run and with no aux start hookup. If something goes wrong, won’t even a lazy lawyer would easily point out their liabilities? I suppose 4WC can also claim that if you modified system and they won’t be responsible.