• Register Today It's free! This box and some ads will disappear once registered!

^^Searches ExplorerForum.com^^

RV Battery Wiring with Inverters/Chargers

I had mentioned on one of my threads (Purchasing 46.5 Acres Near Kingman, AZ) that I had the inverter/charger fail on the RV while camping. Its a Prosine 2.0 made by Xantrex and lasted about 15 years so I can't complain. I purchased a new unit from Xantrex and its being shipped. Most of the camping I do is dry or boondocking. RV has 600 watt solar system along with the inverter so it does very well for extended stays off grid. I pulled the old unit out and don't like the way the batteries are wired, so I think that's going to be a redo and relocation of half of them. RV is a 35' Class A that is a very well maintained 18 years old.
20210428_132259.jpg

20210428_132333.jpg


The batteries for the system are 4 GS2 group size or golf cart batteries. I am upgrading to AGM's because they last twice as long, charge faster, discharge slower and have no maintenance. They are still heavy mothers though, about 65 pounds each. The current set up which was not installed by me has the inverter/charger in the storage compartment directly in front of the entry door, where most of the electronics are located. Good protected spot. There are two batteries in the entry step well, along with the chassis battery. There are two more in the storage compartment directly behind the step well. What I don't like about that is all the weight of the batteries is all in one spot, on one side. I also don't like how it was wired. I am going to relocate the batteries in the storage compartment to the driver side storage compartment directly across from the step well. It will even out the weight distribution, and free up valuable storage real estate since that is one of the few compartments you can easily access with the slides out. That part should be relatively simple; get a new battery box that is in line instead of side by side, mount it and install the batteries.

The wiring should be simple as well. The current set up has one in line 300 amp fuse that is located in the step well. The batteries in the step well connect to that fuse lug with a very short length of 4/0 welding wire, all good. The batteries in the storage compartment connect to that same lug with about a 4-5' length of same type/gauge wire that runs along with the main wiring harness for the coach. Not so good as there is nothing to protect that section of wire from shorting. From the 300 amp fuse is another 5-6' length of same type/gauge wire that goes to the inverter. Also not so good as there is nothing to protect that section of wire from shorting and frying the inverter. To make it much safer, there should be two more 300 amp in line fuses, one at the other set of batteries and one just before the inverter. The wiring from both battery locations should meet at that fuse with a short length of wire to the inverter. The relocated batteries will have the wiring inside the storage area, since its a full width pass through type compartment. I can use the existing wiring from the step well battery location that already goes to the inverter location for that half.

I found everything on eBay, can't believe how much wire has gone up in the past few months. $4 a foot for 4/0.
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private conversations, and more. Join Today. Your support is greatly appreciated.




tdavis

Linux Guru, Jack of All Trades
Staff member
Admin
Elite Explorer
Joined
January 17, 2000
Messages
6,467
Reaction score
72
City, State
Pinole, CA
Year, Model & Trim Level
2001 F250/XLT Superduty
Callsign
KG6MAX
I have these on each battery pack positive post, with a 150amp fuse per battery.


If you don't have access to a hydraulic crimper, find or borrow one. Mine looks this:


Makes it really easy to crimp 2/0 and 4/0 wire, and you get really good crimps.

Soldering is not recommend.

I use one of these to isolate the batteries:


with


That relay is mechanical, in that it draws power only when it switches.
 




tdavis

Linux Guru, Jack of All Trades
Staff member
Admin
Elite Explorer
Joined
January 17, 2000
Messages
6,467
Reaction score
72
City, State
Pinole, CA
Year, Model & Trim Level
2001 F250/XLT Superduty
Callsign
KG6MAX




Mbrooks420

High Voltage.
Elite Explorer
EF Vendor
Joined
February 2, 2002
Messages
11,338
Reaction score
2,074
Year, Model & Trim Level
1998 Mountaineer AWD
Some of the cheaper fuses absolutely explode when they blow.

Agree that a solid crimper is the only way to go.
 




BKennedy

Elite Loser
Staff member
Moderator
Elite Explorer
Joined
November 29, 2000
Messages
8,029
Reaction score
1,456
Location
USA
City, State
San Diego, PRofK
Year, Model & Trim Level
1994 XLT
My research also says that the larger the fuse, the more you should use a t-class fuse.

Something like this:


Something about when it blows, the cheaper fuses don't blow, they explode.
I have almost that exact same fuse block, but it says "Xantrex RV" on it. Had one already, got two more to isolate the other end of wires if one of them shorts. I looked for the same fuse block because I found a couple spare fuses in the RV. I figured out today that its almost the same length wire needed to go from the step well to the inverter and the opposite storage bay to the inverter. Ordered a new end to end battery box that is not as tall with the top fitting over the top of the batteries, which will make them much easier to remove or install than the current box. Current box is about 2.5" taller than the batteries so you have to lift 65 pound batteries up so they are almost touching the ceiling of the compartment while hunched over into the thing. The new box also mounts to the floor from the outside so I can unscrew it and slide it to the edge of the compartment if I need to service the batteries. I think tomorrow I am going to pull stuff out of the storage bays and remove the old wiring, maybe cover the holes the installers drilled into the compartment walls. My Buddy Mike is coming down for the weekend from Idaho and we are going to help another buddy build a metal garage so I don't think I will get to this before next week.
 




BKennedy

Elite Loser
Staff member
Moderator
Elite Explorer
Joined
November 29, 2000
Messages
8,029
Reaction score
1,456
Location
USA
City, State
San Diego, PRofK
Year, Model & Trim Level
1994 XLT
Spent the day removing wiring, running new wires and installing the inverter remote, removing the old battery box and patching three holes in the storage compartment. With the remote, of course its about half the size of the one I removed so I had to fashion a plate to cover half of the hole left by the old remote. I ended up using a piece of 2" wide faux wood blinds painted black. Came out alright, might change it at a later date, or paint it more of a gun metal gray to match the new remote. Found a bunch of messed up wiring behind the remote location, and somehow I broke the connection of the RV alarm's blinking light that is mounted inside the clear door handle.

I used another piece of the old blind to cover one hole, the inside of the vent for the old battery box to cover another, and a piece of 1" wood dowel along with some RTV for the hole in the floor where they had installed a drain.


This is the hole left after removing the old remote. The cleaned up top part is from me with a hand file for the new remote. You can see some of the screwed up wiring in my booze cabinet through the hole.
20210610_111948.jpg

More spaghetti wiring
20210610_115747.jpg


More in the storage cabinet I had to run the remote cable through (I think this is where I must have broke the connection with the alarm light wire). That big taped up mess has a wire nut on the end of it and was shoved up in the access hole. I am not sure what its for, will clean it up later.
20210610_175254.jpg


New remote and cover plate. I'm going to get some wood fill for the screw holes later. Might have to put something in that panel so it looks like it has a purpose.
20210610_175145.jpg


Old battery box. They still make this same box, sells for about $70. Might see if I can get $40 for it on CL.
20210610_175212.jpg


Covered holes in cabinet. Hey, it just has to keep the bugs out, not look pretty. That wire is the remote cable that I need to secure after I mount the inverter/charger. That's supposed to show up on Saturday, along with most of the stuff I ordered.
20210610_175303.jpg


I feel better about putting heavy stuff in those compartments after seeing the walls and floors were made with 1/8" plate with 1" foam core structural panels on top of the floor plates. The compartments are all welded so they must have used constructive adhesive to attach the foam core panels, probably to add rigidity and reduce noise.
 




BKennedy

Elite Loser
Staff member
Moderator
Elite Explorer
Joined
November 29, 2000
Messages
8,029
Reaction score
1,456
Location
USA
City, State
San Diego, PRofK
Year, Model & Trim Level
1994 XLT
That big taped up mess with the wire nut holding 4, 12 gauge wires together was actually the feed for the house battery disconnect solenoid. We all know that you never use wire nuts with 12 volt automotive applications, but I guess this doesn't qualify as far as National RV is concerned. I replaced the wire nut with a solder seal wire connector.

I also figured out that the alarm blinking light feed is connected to the house batteries, which are not there, so it makes sense that the light is not blinking when the alarm is activated. Batteries should be here any minute and I am planning on hooking up one bank of two so everything should work except the outlets controlled by the inverter/charger. Its just as easy to store them in their permanent location than anywhere else, and I can make sure everything works before I clean up and secure the wiring.
 








BKennedy

Elite Loser
Staff member
Moderator
Elite Explorer
Joined
November 29, 2000
Messages
8,029
Reaction score
1,456
Location
USA
City, State
San Diego, PRofK
Year, Model & Trim Level
1994 XLT
I have wiring diagrams, but not diagrams for what other people did after the RV was built. The diagrams for the RV from the manufacture are not accurate as they seemed to disregard the diagrams and just randomly hook stuff to other stuff.

Expedition Portal has turned into one big advertisement over the years so its pretty much worthless. They really don't have anything there for Class A RV's in any case.
 








BKennedy

Elite Loser
Staff member
Moderator
Elite Explorer
Joined
November 29, 2000
Messages
8,029
Reaction score
1,456
Location
USA
City, State
San Diego, PRofK
Year, Model & Trim Level
1994 XLT
No problem.

I got everything I can do without the battery box and the 4/0 copper lugs I ordered. They should be here tomorrow. I cleaned up a bunch of wiring, ran the leads for the batter temp sensor and inverter remote, placed the inverter where I want it to go, installed the fuse at the inverter end, and ran some wiring to where I think it will end up. I didn't mount the inverter as I think I need to move it to secure the cable from the other battery bank as its tight in there. Also cleaned up some crappy cuts made in the back of the storage area that holds the electronics. The back wall is very tight expanded metal to allow venting, but when Camping World cut it up to get the inverter to fit, they did a hack job and did not cover the edges with anything. I used some rubber door molding as edging.

I also called Xantrex tech support one more time. The inverter/charger has a control panel on the top of the box, towards what will be the rear. With limited head room I don't think it will be readable where I want it mounted. They said that the remote is a mirror of the control panel on top of the box so I don't need to be able to see the readout. All I need to see is two green lights anyway to know its connected and functioning properly.
 




Top