Replacing House Batteries

Dennisemory · 03-06-2021, 07:58 PM

2017 Thor Hurricane 29M - Great coach. I'm inspired by this site and need to replace my house batteries. I am thinking of Battle Born Lithium and would like to clean up the battery compartment at the same time as it is a mess. All these wires scare me off but I'm sure someone has cleaned it up. If I were clever I would put the new battery under the dinette seat and use the current battery compartment for additional storage. But doing something with all those wires is daunting. Is my "hate messes" complex trying to fix something that isn't really broken worth the effort? What have you done with all this excess wiring? For a company that seems to cut lots of corners, I am amazed at the coils of extra wire I find in many places.
Love the coach - it is perfect for the two of us - and I have more time available than talent to do things to it. Any ideas?

AxialFlux · 03-08-2021, 02:02 AM

Excuse my ignorance, but what is with the orange paint on the terminals?

Edensob · 03-08-2021, 02:10 AM

Probably a corrosion prevention sealant. Always a good idea to use on any battery connection to prevent corrosion which will produce resistance, perhaps heat, and connection loss. It's one of those semi annual items to make sure and check. An small aerosol can is pretty reasonable at any Autozone

AxialFlux · 03-08-2021, 02:17 AM

I didn't even know they made such a thing. Might be worth looking into.

Edensob · 03-08-2021, 02:21 AM

AxialFlux · 03-08-2021, 02:30 AM

tgsmith4845 · 03-15-2021, 10:41 PM

2018 ACE 30.4

I think these rigs all come with a “one size fits all” wiring harness. Cheaper for the manufacturer to just have one harness, I guess, and coil up all the excess wiring and zip tie it out of the way. I’m tempted to rewire the entire MH to get rid of it but I’m sure I’d leave at least one circuit disconnected when doing it. For now, I’ll just ignore all that excess wiring and enjoy the MH.

As far as the battery compartment goes, ours was a bit of a mess also. When I installed an inverter a few years ago I cleaned up as much wiring as I could. I would’ve reluctant to relocate your battery inside your MH because of mess and vapors. I know the sealed Battleborns don’t vent, but I’d rather not have them inside my MH regardless. I’ll be replacing our standard batteries with Battleborns once they wear out this year or next (3-4 years use).

Good luck!

Redbeard · 03-20-2021, 10:01 PM

We have a 2018 Windsport 29M....same. Yes, the wiring is a mess and makes it difficult to work on the batteries. It's almost impossible to trace the wiring to determine the circuitry. It would be a big job to move them. I installed positive and negative bus bars to the left of the batteries and connected everything to them....only two wires going to the batteries. That helped somewhat, especially when removing the batteries. It also enabled the installation of a Victron BMV-712, which I find to be very useful.

The_Breeze · 03-20-2021, 10:16 PM

If those are not 12v cables, disregard what follows.

12v runs are notorious for loosing volts/amps over long runs. The longer the run, the more the loss. A quick measure with a multi-meter may prove the point.

Take a measurement at the battery. Compare that measurement to your input at the distribution panel. Note the difference.

In my case, the batteries are under the entry steps (front). The power panel is under the bed (rear). Twenty-two feet. 12.5v at the battery registers as 11.7/8 at the power panel.

The shorter you can make your 12v cables, the better off you'll be. Your mileage may vary based on other factors: batteries themselves, corrosion, length of cable.

Bob Denman · 03-20-2021, 10:30 PM

What he said: these things are chock-full of compromises.

halfprice · 03-20-2021, 11:28 PM

Quote:

Originally Posted by Redbeard

We have a 2018 Windsport 29M....same. Yes, the wiring is a mess and makes it difficult to work on the batteries. It's almost impossible to trace the wiring to determine the circuitry. It would be a big job to move them. I installed positive and negative bus bars to the left of the batteries and connected everything to them....only two wires going to the batteries. That helped somewhat, especially when removing the batteries. It also enabled the installation of a Victron BMV-712, which I find to be very useful.

Nice work. Just one point or observation. There is a power cable running to the 50 amp fuse breaker. Maybe that's your unk cable

Just looked at your diagram again and see you have power cable hooked to the bus bar and going to the 50 amp

FYI that 50 amp runs to and powers the main breaker panel at the base of the bed
Jerry

Redbeard · 03-21-2021, 04:03 PM

Thanks Jerry. I do have a couple of questions for you.

First: The wiring to my BIM was reversed and I just corrected it. There were two wires going to the coach terminal (before I reversed them). One was a larger gauge wire...do you know what it is for?

Second: I really appreciate your modification thread. Is there a way to search it for specific topics?

Thanks,
Al

campy · 03-22-2021, 11:47 AM

I have a 2017 Thor Compass and my wiring looks like your in the photo. I just replaced with Battleborn battery(single 100amp). There is more to it than just replacing battery. 1st need to upgrade to lithium charger in your panel house box. Not hard to do at all.{progressive dynamics PD4655liv}. Add the battery monitor {needed! Victron BMV712}. What I found is the AC and generator charged battery fine. I couldn't get any charge out of my vehicle alternator at all. I am getting this week DC/DC Orion charger so I can charge going down the road with engine on. I wouldn't have know that I was getting no charge without the monitor. Found out the refrigerator on DC is a big power hog as well! Hope this helps. Carl

halfprice · 03-22-2021, 03:59 PM

Quote:

Originally Posted by Redbeard

Thanks Jerry. I do have a couple of questions for you.

First: The wiring to my BIM was reversed and I just corrected it. There were two wires going to the coach terminal (before I reversed them). One was a larger gauge wire...do you know what it is for?

Second: I really appreciate your modification thread. Is there a way to search it for specific topics?

Thanks,
Al

Hmmm not sure. The connection you switched was it battery a and b??? Many people say thor wired it In reverse l called precision, bim manufacturers, and was told it didn't matter for gas motorhomes

Not sure on on the wires. I haven't looked at the bim in several years. Sorry But I'd suggest calling precision. Their customer service reps are great

As far as search I use my cell and tap a talk app. It has a search this thread function

If using a computer i also think, but could be wrong, that if you are on the thread then go to search bar it asks where to search and key words to search for

There is no formal or organized list of items on the thread

Jerry

Dennisemory · 03-23-2021, 06:45 AM

After much thought, I took the easy way out and just replaced the existing batteries - like for like. I took pictures before removing old batteries and zip tied the wires together as I removed them from each terminal. I bought new batteries and thought I could go up a size to Group 29 from Group 27 but found out they wouldn't fit into the battery compartment. I returned them and got the Group 27 size and they fit and I managed to take a half hour job and stretch it out for two weeks. - but I did it and it works great. At $96 for each battery I can run them until they drop and then think about this question again. Thanks for all the help.

CHS · 03-24-2021, 11:41 AM

I thought of going with lithium batteries but was talking with a fellow camper that has them installed along with solar panels and we came to the conclusion that since we did not do that much dry camping and are usually hooked up to electric, and that it was an expensive overkill. I replaced mine with AGM type so at least the cells are sealed and no excessive acid gas vapors.

Vibeman · 03-31-2021, 11:47 AM

I have a 2020 29m and the battery compartment was a mess too. My goal was to make it easier to check and add water. I took lots of photos, drew and labeled a diagram and tagged some wires. I then disconnected all cables and removed the batteries and turned them 180° so the posts were towards the back of the compartment. This gave much better access to the filler caps. I then played around with routing the cables as I reattached them to keep them clear of the filler caps. With a flashlight and an inspection mirror I can now fairly easily check the water level in both batteries and add water too. I have attached before and after photos, they are sideways (should be rotated 90° clockwise)but you get the idea.

Dennisemory · 03-31-2021, 06:12 PM

Vibeman,
Very nice job. Were you able to use the existing wiring or did you have to replace some of the cables?

Gmthrust · 03-31-2021, 06:43 PM

Quote:

Originally Posted by Vibeman

I have a 2020 29m and the battery compartment was a mess too. My goal was to make it easier to check and add water. I took lots of photos, drew and labeled a diagram and tagged some wires. I then disconnected all cables and removed the batteries and turned them 180° so the posts were towards the back of the compartment. This gave much better access to the filler caps. I then played around with routing the cables as I reattached them to keep them clear of the filler caps. With a flashlight and an inspection mirror I can now fairly easily check the water level in both batteries and add water too. I have attached before and after photos, they are sideways (should be rotated 90° clockwise)but you get the idea.

I like your labeling of + and -

Redbeard · 03-31-2021, 08:22 PM

Nice job Vibeman! I might do the same when replacing my batteries. As an alternative, the Qwik-Fill battery attachment that is sold at RV supply houses works pretty well to top off the battery water. I found it a little difficult to install (would be much easier if I did it again) but definitely worth the trouble.

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