Upgrading Wiring to Charge Camper Batteries From Truck?

[So Cal Adventurer]

Hey All

I know its been done before, but anyone have any good writeups or links on how to upgrade the 10 gauge wiring from the camper to the plug for the alternator?

I have 2 gauge from my truck up to where my FWC plug connects.

I'm looking into upgrading the wiring from the isolator in the camper, to the plug, and to the camper batteries so i get maximum charging when driving.

I'm sure its been done before. I opened it all up and got in there, but couldnt get a good read on what goes where without really digging into it and removing some things.

I have a 2018 Hawk.

Thanks

 

[Oilbrnr]

On my '17 Hawk, it is just the black and white 10 AWG wires coming in from the front to the Blue Sea and neg term of the battery or ground block (can't remember exactly) that would need to be upgraded. 2 AWG is pretty beefy stuff and probably overkill.

You can use an Andersen connecter in leu of the Attwood trolling motor connector.

Better to use this RedArc BCDC isolator which will compensate for the voltage drop and properly handle bulk, absorb and float level profiles of AGM or LiPo's than your trucks charging system will.

 

[Vic Harder]

add in a couple of breakers at each end i use blue sea 285 series 100a in mine

 

[craig333]

Definitely need a couple fuses at least. Not that any of these DC-DC chargers aren't nice but unless you're planning on charging solely from the truck, I don't see them being necessary. The way I look at it, on the rare (hasn't happened yet) times solar isn't enough, I'll just the need truck for a bulk charge, figuring soon enough the solar will come back into play and finish it off. If the weather is that bad that it doesn't happen then I need head for home

 

[So Cal Adventurer]

Thanks.

Fuses will be added for sure.

I’m more looking for a good schematic, of the FWC wiring if anyone happens to have one. 2018 Hawk front dinette.

I’m not really sold on those DC to DC things honestly...

I use a POWER GATE isolator (not well known, but made here in SD and used extensively by the military and in aviation) I’ve used them approximately 15 years with AGMs and had flawless results.

You can read about them here:

www.http://perfectswitch.com/

I think the pricey DC to DC things are a marketing thing.

A good isolator does the exact same thing. Lots of cheap isolators are on the market and don’t do more than connect the batteries.

I can’t see the benefit of them for a Toyota and how Toyota alternators function.

Thanks for the input. I’ll keep hunting for a schematic

 

[So Cal Adventurer]

2 AWG is pretty beefy stuff and probably overkill

You can use an Andersen connecter in leu of the Attwood trolling motor connector.

Yeah, I have lots of 2 gauge lying around from previous dual batt installs for friends.

Anderson connector is a damn good idea.

Thanks

 

[ntsqd]

I prefer the 285 Series breakers to fuses. Makes for an easy pair of disconnect switches in addition to protecting those cables. Does make that circuit a bit less tolerant of momentary over-currents, but at those current levels I'm OK with that.

 

[Oilbrnr]

Thanks.

Fuses will be added for sure.

I’m more looking for a good schematic, of the FWC wiring if anyone happens to have one. 2018 Hawk front dinette.

I’m not really sold on those DC to DC things honestly...

I use a POWER GATE isolator (not well known, but made here in SD and used extensively by the military and in aviation) I’ve used them approximately 15 years with AGMs and had flawless results.

You can read about them here:

www.http://perfectswitch.com/

I think the pricey DC to DC things are a marketing thing.

A good isolator does the exact same thing. Lots of cheap isolators are on the market and don’t do more than connect the batteries.

I can’t see the benefit of them for a Toyota and how Toyota alternators function.

Thanks for the input. I’ll keep hunting for a schematic

So directly connecting two dissimilar battery types, at different stages of their lives, with charging system designed primary for bulk is the way to go.

 

[larryqp]

So directly connecting two dissimilar battery types, at different stages of their lives, with charging system designed primary for bulk is the way to go.

This thread has wandered a bit, sort of, but electric system is so intertwined.

I'm trying to get a handle on all this especially since I am literally starting from the beginning again. My conclusion was that without a DC to DC charger and having a flooded lead engine battery and an AGM house battery bank:

1- There might be a slight delay in charging the house batteries if they were extremely low, but my thought was on a long driving day that would be moot.
2- Most alternators wouldn't be able to "top off" the AGM batteries, but one could "finish" them off with solar as long as it was sunny.
3- There is the inherit problem of having dissimilar batteries connected together
4- There is the inherit problem of having batteries of different ages.

Given the cost of a DC to DC charger, and the fact that I plan to have 200 watts of solar on the roof and 200 aHr of AGM house batteries. Couldn't I just:
1- buy a new AGM engine battery when I install the batteries in the new camper? and skip the DC to DC charger. My new to me truck is a 2016, so assuming its the original battery, its almost time to replace it anyway. The cost difference between a flooded lead and a AGM starter battery is only about $100. Plus I'd have the benefit of a starter (engine) battery that would handle vibrations better.

2- Bring larger wire to the installer and upgrade the wire from the usual 10ga that FWC does to say 6 or 8 gauge?

Somewhere in one of these threads, someone stated and I agree, that given a large solar array, and proper battery bank, you probably should need charging from your alternator anyway.

Looking forward to opinions.

 

[ntsqd]

For several years we ran the reverse set-up. AGM's in the engine bay and FLA's in the camper. To make matters worse the FLA's were old and had been abused, both by the PO and inadvertently by me. We still got 4-ish years out of them before I was forced to replace the camper batteries. I put in AGM's.

All of this still on the OEM alternator regulator.

About 1/2 way thru the life that we did get out of those FLA's I installed 100w of solar. I am fairly sure that it was the reason why those batteries lasted as long as they did. After that the alternator rarely had to charge them.

I ran 6ga. and I arrived at that size by assuming a max charge rate of 80 amps. Input that and the total circuit length into the Ancor Wire page's chart or formula (I forget which I used) and it showed that 6 ga. was the needed size. For wires this big no connector supplied by a camper mfg is going to work. The limit for those is 10ga. if that. The Anderson connectors (Grainger.com & powerwerx.com) are the best way to go.

 

[Vic Harder]

This thread has wandered a bit, sort of, but electric system is so intertwined.

I'm trying to get a handle on all this especially since I am literally starting from the beginning again. My conclusion was that without a DC to DC charger and having a flooded lead engine battery and an AGM house battery bank:

1- There might be a slight delay in charging the house batteries if they were extremely low, but my thought was on a long driving day that would be moot.
2- Most alternators wouldn't be able to "top off" the AGM batteries, but one could "finish" them off with solar as long as it was sunny.
3- There is the inherit problem of having dissimilar batteries connected together
4- There is the inherit problem of having batteries of different ages.

Given the cost of a DC to DC charger, and the fact that I plan to have 200 watts of solar on the roof and 200 aHr of AGM house batteries. Couldn't I just:
1- buy a new AGM engine battery when I install the batteries in the new camper? and skip the DC to DC charger. My new to me truck is a 2016, so assuming its the original battery, its almost time to replace it anyway. The cost difference between a flooded lead and a AGM starter battery is only about $100. Plus I'd have the benefit of a starter (engine) battery that would handle vibrations better.

2- Bring larger wire to the installer and upgrade the wire from the usual 10ga that FWC does to say 6 or 8 gauge?

Somewhere in one of these threads, someone stated and I agree, that given a large solar array, and proper battery bank, you probably should need charging from your alternator anyway.

Looking forward to opinions.

First off, AGM and Flooded Lead Acid (FLA) are both lead acid chemistry batteries. Not dissimilar enough to be worrisome.
The issue with some of the isolators and thin wiring used in camper to truck connections is not just a "delay" in getting connected, it is repeated connection & disconnection. Workarounds include a simple switch to force the connection, but that doesn't get around the voltage drop that causes the disconnection in the first place. The "fix" is either thicker gauge wire or a DC-DC converter.

See what happens is that the isolator "senses" the disparate voltages present at the two battery terminals and the charging terminal. If there is enough of a charge voltage, it wants to connect them, and does. As soon as it connects, the power starts coming over the wires, and the heat of going over such a thin wire causes the voltage to "drop", and not be enough to warrant connecting them. So the isolator disconnects. And then immediately senses that there IS enough voltage to connect, and does so.... repeat. Click... Click, Click.... And not much charging happens.

Plus, many new trucks have "smart" alternators that don't produce enough voltage at to be of much use when the juice gets the 25' or so from the alternator to the camper batteries. Even with 2g wire I saw a .5 volt drop at 80A. Toyota was one of the first with this issue, and folks have used the CTEK product to get around that issue. The newer Redarc stuff looks great too, and you might even not need a separate MPPT controller at all. I like my bluetooth Victron gear though!

The reason the alternators are good for "bulk" charging is that they are relatively dumb, but big. The finesse needed for a particular battery chemistry is better left to electronics that understand the specifics for your battery.

You can certainly try to use just 200w of solar with 200AH of battery. just make sure you have a good monitor (Victron BMV) so you can tell if that's enough.

If you are going to upgrade the wire from the camper to truck, I'd think 4g is big enough. 2g was overkill in my case.

 

[Optimistic Paranoid]

"1- buy a new AGM engine battery when I install the batteries in the new camper? and skip the DC to DC charger. My new to me truck is a 2016, so assuming its the original battery, its almost time to replace it anyway."


I'm not sure why you think it's time to change your starter battery. In my experience, OEM batteries are usually good for anywhere from 5 to 7 years on average. They start the vehicle and the alternator immediately supplies all the power to run the vehicle and bring the battery back to full charge. They rarely fall below 95% SOC, and that kind of cycle does WONDERS for a battery's longevity.

 

[Vic Harder]

+1 on battery life. in over 40 years of vehicle ownership, i’ve replaced only one battery. but if it’s shot, its shot

 

[rando]

The on/off cycling of the isolator is somewhat specific to the Surepower isolators - they don't have the built in time hysteresis that the blue sea isolators have, that largely solves the on/off cycling issue. Another way to deal with this is to mount the isolator under the hood, so there is no long wire run between the alternator and the isolator and the voltage does not drop when the isolator combines the batteries.

 

[larryqp]

well I picked up the 2016 F150 FX4 today and it has a AGM starter battery, so the removes that issue. So I have another question for the gurus.

If the issue as rondo states is the on/off on/off cycling, wouldn't this be eliminated if you skipped the isolator, ran say 10 ga positive and negative wires from the engine battery to the house batteries with an appropriate sized switch under the hood. For the few times that solar failed to charge the house batteries, then start the engine, engage the switch and current would flow from the alternator to the engine battery and then to the house batteries. In effect you would be charging the house batteries from the engine battery and the alternator would only "see" the engine battery, maybe?????

Then you could still run a set of wires from the engine battery terminals on the solar controller back to the engine battery.

You would need to provide fuses or breakers at each end for protection.

Anyway, I'm way out of my realm here, so please correct me if I'm crazy

 

[Vic Harder]

yes, you could control the connection manually. i’d want gauges to tell me what is going on though. voltage at each battery, and current flow between them as well

 

[cwdtmmrs]

Whenever I read these threads I get dizzy! The only charging I have in my 1986 Toyota pickup is from my 120 amp alternator. The starting battery is a FLA and the camper battery is a Yellow Top Optima and are connected by a simple constant duty 50 amp solenoid triggered off of the accessory circuit. I did run 4 ga wires in addition to the factory 10 ga wires. I have a 3 way fridge so I don't use a lot of power. I do have a heater and water pump though. I usually drive everyday to a trail head or fishing, etc. I don't have any gauges to even check SOC's. I have never once run out of power and the Optima is going on 12 years old and on my 2nd FLA starting battery.

 

[pvstoy]

CWDT having a simple system that meets your needs is great. In my previous two FWC I had the similar set up and survived just fine. You must have upgraded your alternator to 120 amps as stock is 50 to 70 amps.

No need to get dizzy as there are a whole lot of marketing products that will do just about anything. Of course at a cost and learning curve. Some day down the road you might replace the truck and camper and some of the things you are reading now that make you dizzy might make sense later. Don't sweat it and enjoy your present ride.

I bought a 2015 Hawk flatbed that has a DC refrigerator that has a high demand for power. I jumped in and did the learning curve and rewired and added new technology along with solar panels. I'm pleased with the outcome as the solar has always keeps up with the DC demands. In the camper I installed a Blueseas isolater system with three way switch and it is left in the off position. I have yet to use the alternator to charge the dual 80 amph batteries.

All my rewiring and upgrades came with a cost and learning curve, but pleased in the end result and understand how it all works.

Simple is great, always try to maintain simple. It is easy to maintain and fix if needed when things go wrong.

Cheers.....

 

[radarcontact]

Hey All

I know its been done before, but anyone have any good writeups or links on how to upgrade the 10 gauge wiring from the camper to the plug for the alternator?

I have 2 gauge from my truck up to where my FWC plug connects.

I'm looking into upgrading the wiring from the isolator in the camper, to the plug, and to the camper batteries so i get maximum charging when driving.

I'm sure its been done before. I opened it all up and got in there, but couldnt get a good read on what goes where without really digging into it and removing some things.

I have a 2018 Hawk.

Thanks

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.

 

[cwdtmmrs]

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!

It just seems like every other post on WTH nowadays is something to do with solar, batteries, charging, etc. not working. That or suspension upgrades to handle the extra weight.

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.