I need more power Scotty!

thanks rando. the Victron Phoenix inverters do have their own lv disconnect. I am going to try running the whole DC load side from one of the load outputs. If it fails, I can always put the highest load item (the fridge) on a separate circuit.
 
If you're going to rewire it anyway treat the camper like a wooden or fiberglass boat, run appropriate sized grounds from all users to some sort of ground buss.

I don't think that the camper itself needs to have a truck ground. If you charge off the alternator and the wiring for that system is essentially battery to battery then when that system is active the camper's ground buss will be truck grounded via the starting battery ground(s). When it isn't active the camper will float from the chassis and be it's own whole system. Other than maybe a lightning strike I've yet to find a fault in that.
 
Thanks Vic! I have learned a lot from your post. I just installed Trimetric TM-2030 RV and SC-2030 on my Grandby. I could not and would not have attempted to do the install without reading up your post and many others who have contributed so much to the topic. The Bogart Engineering engineers must skipped their English classes in college. It was and still is very confusing reading the several manuals. Anyway, got them installed and will try to understand programming it as I learn about them.

Next, upgrading wiring from truck to camper. I have a GMC Duramax diesel with two batteries. I am not sure if I need to run heavier awg from BOTH batteries to camper or just to one of the battery, and I like to use Anderson connectors as you did since I did that for my winch power connection and it was pretty easy. If I need to tap into both batteries on the truck, how can I funnel both battery cables into one line and one Anderson plug to tie in with the camper. I looked for a common port but no luck so far.

I don't have much power need in my camper, just one DieHard Platinum 12 volt with only 68 AH, but may plan to go with two batteries in the future. I got a 125 watt panel on the roof and it has worked well for my need so far. I like to get a portable 100 watt folding or flexible panel in the future so I can aim the panel in the Winter or when I am parked in the shade. I like to use two separate portable wiring options, one short line just long enough to the top of my truck cabin, or to the ground next to the truck, and another longer, say 30 feet so I can find some sun if needed. Should I use the buddy MC4 plugs on the panel wiring? Also how can I keep the existing panel controller and just have the option of bypassing it when I want to and still keeping the option of using the panel as stand alone charging source.

Any picture of your truck to camper wiring and connections would be appreciated. Thanks for your help.
 
The short answer is assuming good condition that you probably are fine with the battery to battery cable(s) already in place.

The long answer goes like this: Required wire gauge is relative to the amperage flowing and the distance. The garden hose flow vs. length metaphor directly applies here. As an example a 100 amp current needs a 4 gauge wire for a circuit length of 10 feet, but needs a 1/0 ("single ought" for those not familiar with the lexicon) cable for a length of 30 feet and a 4/0 cable for a circuit length of 60 feet.
Can think of each segment of the whole as a circuit length, i.e. the section from the battery to the breaker or fuse next to it can be 4 gauge for the 100 amp current. The next segment from the engine bay breaker/fuse to the camper breaker/fuse is 30 feet long so it needs to be 1/0 cable for 100 amps (which is a lot). Keep in mind that the actual length of each segment includes the ground path too.
 
ntsqd, thanks for the info on wire gauge needs, I understand the bigger the better, but I am more confused as to how to upgrade the wiring from the two batteries from my truck to the camper. The existing wiring is inadequate and is wired in with the battery on the driver side only, not sure if that is the primary or secondary battery. My original question was if I need to tight in with both batteries directly and then to the camper. I know that both truck batteries are bused together already, but I doubt they are getting much charge via existing 10 gauge wire from my camper/solar power. I always assumed that if the driver side battery is getting some charge, the passenger side is also getting some juice too from the camper solar power.

I just replaced both truck batteries. Good thing I was home and readying for a trip when the batteries died. Called AAA, but they couldn't help with just hooking up to one of the battery and they had no way to give me boost to both batteries. I want to insure that I have some backup options in the future when I am out in the boonies.

I need help with how best to set up upgrading the wiring more than help with deciding what gauges I need and where.
 
muttmaster said:
I need help with how best to set up upgrading the wiring more than help with deciding what gauges I need and where.
Click to expand...
Muttmaster, I will try and get some pics later today. What ntsqd/Thom said is right on, you need bigger wire for more distance. I went with 2 AWG from the truck battery all the way to the battery box on the camper. 20' distance, and depending on which tool you use to calculate voltage drop, that should be 20' or 40' to include the return run as well.

My breakers are 100A, as my alternator puts out a max of 130A. I suspect it won't be doing that often, if ever. I will know soon enough, as I am putting in enough meters to be able to tell what's going on.

The max my solar will put out is 47 amps, and the 2awg will be plenty to carry that back to the starting battery.

Does your truck have an isolator for the two starting batteries? If they are both connected all the time, then running just one set of wires back to the camper is enough.
 
Vic, thanks for the reply. I can't find my 2007 Duramax manual so I don't know if I have a Isolator or not. I assume the driver side battery is the primary and the passenger side is the auxiliary, or if the OME GMC didn't use a isolator, both battery is considered primary as it takes a lot of juice to start the diesel. I suppose I could measure voltages from both battery, etc. It would be shorter distance to my camper battery if I tap into the passenger side, so maybe that is what I will do whether it is auxiliary or not. I suppose that is ok. Right now the driver side battery is tapped to go into left side of the camper. I suppose I can keep that connection...or not. Maybe I shouldn't worry so much, but just want to do it right this time.

Thanks for any help.
 
Typically diesels need two starting batteries and they are wired in parallel, there is no primary/secondary relationship. Tapping into one taps into both. Be sure to install a fuse or breaker right near the tap. With a battery on both ends of the truck to camper cable there needs to be protection at both ends too.

The typical charge rates of solar won't tax the wiring nearly as much as the alternator can. Said differently, with the lower amperage charge from solar the voltage drop concern is also lessened because there is less current to heat the wire.
 
Thanks, Thom. I appreciate your input and suggestions to a novice wire hacker. I found out on Duramax forum that stock GMC truck batteries are parallel connected as the diesel need both battery to start the engine, so no isolator in the truck. I will tap into passenger side battery to go to the right side of my Grandy battery. Learning so much by doing and reading all the post and hopefully not making too many mistakes along the way.

I didn't learn anything from my electrical engineer brother who told me 40 years ago.... Read all directions when all else fails.
 
muttmaster said:
Vic, thanks for the reply. I can't find my 2007 Duramax manual so I don't know if I have a Isolator or not. Maybe I shouldn't worry so much, but just want to do it right this time.

Thanks for any help.
Click to expand...
Here are some of the promised pics.

100A breaker at the starting battery
full


Cable routing in engine bay
full


Anderson Power Pole on the camper
full




2AWG wire entering camper on driver's side
full



You can just see the 100A breaker in the top right corner that this cable will terminate at
full


The electrical controls panel
full
 
Thanks for all the pics. Very nicely done. I am inspired. I ordered everything I need and will keep it simple and allow room to expand in the future. This is kind of fun and I am going for it. Good thing I have some time right now. Thanks for all the sagely advise.
 
I finally got the panel mounted into the battery box - and am using internal power rather than trouble lights to work on the camper!

Mounted
full


Big blue box is the Victron inverter, with a switch and relay next to it to allow me to shut it down remotely. It draws 0.5A idling.
Next to the relay is the Blue Sea DC power panel with power point and dual USB.

Battery cabling is 2AWG (not 2/0) all the way back to the starting battery via the Blue Sea ACR.

Lid closed with storage above
full




Some of the wires are yet to get nicely tucked away
full


Revised panel

full


I was reading about the controllers and the manual clearly states that they are to be mounted on "non-flammable material" - wood? NOT. So I made some standoffs to keep the heat sinks on the back 1/2" away from the wood board. Also removed the 40A breakers from the PV panel inputs, and used one for the load output to the DC panel.

Now to finalize the Solar Panel install and test that out. I would through the portables outside, but I have not been able to program the dual MPPT controllers yet. Waiting for my Blue tooth dongle. The gauges/controllers are supposed to provide access to the settings, but are very hard to use. Not to mention I can't find a manual for them that shows how to do that. That's a downside to the Victron stuff.

Another downside is that the cable connector for the MPPT units is now buried deep in the battery box. Plugging in the bluetooth dongle will require some major disassembly.

Also, the remote switch connector on the inverter is a little plastic dongle that sticks out of the unit just far enough to easily get broken off. Ask me how I know....
 
I havent' seen either of mine get more than slightly warm. Better safe than sorry though. Looking good.
 
craig,

Any idea what type of connectors they are using on these units? I'd like to make a junction box, so I can unplug the cable from the guage, and plug in the blue tooth dongle. Right now, I'd have to take out the batteries, and pull the board out again so I can get at the plugs on the controllers and swap cables. PITA.
 
Hi there

Newbie to the forum here. Just picked up a new Grandby shell model (furnace, stove and camper battery factory installed) Have been reading this thread with interest trying to sort out what am going to do with it.

Have used Victron products in boats and have always been impressed. I actually have a Victron Phoenix charger looking for a home, so step one is handled, I guess. Planning on adding shore power and solar to keep 2 75Ah AGMS topped up. (Shore Power not available on shell, worth it to have when ac power available).

Still trying to get my head around the wiring for solar plus alternator plus ac charger and how that all gets wired to the battery. the alternator is not ideal charge for AGMs and solar/charger will be set up for house batteries so that is not ideal for start battery..... possibly just a marine style battery switch to isolate start and house batteries if required?

Anyway, thanks to all of you for the information posted so far.

Cheers
 
If you are concerned about non-optimal charging of the house batteries from the alternator, and of the starting battery via the solar panels and are OK with manually switching them, then you can not bother with connecting the two systems at all. If you want the option of connecting them, then a simple marine grade battery switch can do the trick. Most here are ok with the two systems being interconnected, and the "go to" solution seems to be the Blue Sea ML-ACR 7622.
 
Thanks Vic,

I have ordered the 7622, and the Victron solar controller. Shameless copying of a good plan I will admit. Though as I mentioned I have worked with Victron stuff on boats previously and like their products.

My concern with switching out the truck battery was due to charging the one AGM out of the camper and re-installing it to find a couple of hours later the BlueSea 7611 the factory installed had closed the circuit to the truck battery (nothing running or "on). I guess the voltage right after charging was high enough to trigger it. The factory had set the low voltage "jumper" to allow the truck battery to supply limited power, which also sets a low voltage shut off. Sounds good in theory, but I don't really want the truck battery supplying any power to the camper without the alternator.

Also wasn't entirely sure about feeding 2 potential charge currents at the same time to the battery. (Solar and alternator) All the schematics I have seen so far do just that however, so it must work.

Side note - I just retired and the camper was part of that plan - now I don't go through Calgary every 3 or 4 days. Just as well, or I would have been pestering you for more ideas!!

Thanks again
 
I would suggest duplicating what you did again, only this time after the VSR has closed put a load on the camper battery. Run the fridge, turn on the heater, something that will pull some amps. See if the VSR doesn't open fairly quickly. If it does open I would not worry about it.

FWIW even with just 100w of solar I have yet to need to use shore power to charge the camper batteries.
 
You must log in or register to reply here.

Similar threads - WTW

O
MPPT controller at 13.64v - Blue Sea meter at 12.35v - Batteries not charging
Jon R
J
G
Need help planning for Solar and DC to DC
2 3
Glenn
G
O
Battery Voltage question
2
Outnabout
O
B
A little help
Vic Harder
Vic Harder
K
Batteries: Parallel vs Stand alone w/ transfer switch
Krist003
K

New posts - WTW

Back
Top Bottom