I would like to see your Electrical/Power Setup

[Nightmare]

I've been researching an upgrade to our RV power system. I'm still not sure what I want to do, after a visit to the local RV shop I'm in some sticker shock.

Our RV and the 'stock' equipment

2017 Thor Quantum GR22
- 2 of the Interstate 12V RV batteries (these are 100% shot, multiple dead cells)
- Onan 4KW Generator
- Whatever stock charger/converter that Thor installed (I'm sure it is cheap)
- 5100 Series Transfer Relay

I thought I would be able to just install a new Inverter next to the transfer relay, but the shop guy tells me that isn't the 'right way'. Sounds like they charge about $2,000 to install the inverter with a separate sub-panel (so the things I don't want the inverter to run are separate.

I planned to get a big AGM battery (200+ AH), but he tells me that it won't work much better than the Interstate 12v (discharge % and stuff like that).

They suggest either 6v Deep Cycle (which may not fit under the step) or go FULL SEND and get a Li Battery. Which requires a new Charger and possibly other upgrades.

I really don't think we will be boondocking for more than a week at a time. I mainly want the ability to run the TVs off the inverter. I guess I could just buy a portable inverter...

So what do you guys have? And if you are willing to share the cost.

Thanks

[DavidEM]

My 2021 Thor Axis has essentially the same power setup as you describe. I have made two changes: I replaced the two G27 FLA batteries with two G31 AGM batteries and I replaced the WFCO 8955 charger part of the converter with a Progressive Dynamics unit.

The first gives me 25% more amp hours and freedom from checking and adding water. The second gives me somewhat faster generator charging.

So, here are some comments on your shop's recommendations:

A separate AC panel for only those services that need to be inverter powered is the best way to go- no chance of an endless loop of powering the battery charger from the inverter but the batteries power the inverter.... But it is a bit expensive as you have noted. A portable 500-1000 watt inverter would work fine with your TV.

But I have to ask, why watch TV when you are boondocking? I hang out by the fire with a good book or conversation with a shot or two of nice bourbon.

I am not sure why they are pushing GC2 batteries. Yes a pair gives you 220 amp hours vs 200 amp hours for my AGMs. I can't think of any other advantages, although golf cart batteries can withstand many cycles of charge/discharge but so can AGMs and AGMs don't require water checking and adding.

To be able to camp for 7 days with no battery charging will probably require 200 amp hours of lithium batteries. They will also require a different charger compatible with lithiums and you may also need a DC to DC charger to limit amperage drawn from the alternator which presents its own problems.

I use about 25 amp hours daily while boondocking with an absorption fridge. I can go for 4 days and stay at or above the 50% discharge recommendation. Once I get down to 50% I start the generator and run it until the batteries are up to 85%. Doing that twice will get me through a week of boondocking, but I have never gone that long.

So, my recommendation is to get a portable inverter just for the TV and replace your bad FLAs with a pair of G31 AGMs. If you do significant boondocking then replace your WFCO charger with a PD charger for better charging performance while running the generator every 3 days or so.

David

[Nightmare]

Originally Posted by DavidEM

Once I get down to 50% I start the generator and run it until the batteries are up to 85%. Doing that twice will get me through a week of boondocking, but I have never gone that long.

Do you have a device that measures the discharge? Or is there just a linear scale based on the resting voltage?

[ducksface]

He's right about everything but the 6v battery myth.

The 6v is a perpetuated lie from the 1930's.
It's a laboratory gain not a real world real use gain. It has to do with minute changes in plate size.
Run a 3w bulb on 12v for 30hours, run it on two 6v for 32hours.

He'll kick and scream and call me names about my 6v blasphemy.

Get the lithium.
Buy some happy.

[Beau388]

Originally Posted by Nightmare

I've been researching an upgrade to our RV power system. I'm still not sure what I want to do, after a visit to the local RV shop I'm in some sticker shock.

Our RV and the 'stock' equipment

2017 Thor Quantum GR22
- 2 of the Interstate 12V RV batteries (these are 100% shot, multiple dead cells)
- Onan 4KW Generator
- Whatever stock charger/converter that Thor installed (I'm sure it is cheap)
- 5100 Series Transfer Relay

I thought I would be able to just install a new Inverter next to the transfer relay, but the shop guy tells me that isn't the 'right way'. Sounds like they charge about $2,000 to install the inverter with a separate sub-panel (so the things I don't want the inverter to run are separate.

I planned to get a big AGM battery (200+ AH), but he tells me that it won't work much better than the Interstate 12v (discharge % and stuff like that).

They suggest either 6v Deep Cycle (which may not fit under the step) or go FULL SEND and get a Li Battery. Which requires a new Charger and possibly other upgrades.

I really don't think we will be boondocking for more than a week at a time. I mainly want the ability to run the TVs off the inverter. I guess I could just buy a portable inverter...

So what do you guys have? And if you are willing to share the cost.

Thanks

Unless you only want to power a single electrical circuit, an electrical sub-panel is highly recommended. The size of your inverter is dependent on the size of your battery bank.
The reason CG-2 golf cart batteries are recommended is they are the cheapest true deep cycle per amp-h. An AGM battery is a type of VRLA battery. It is simply the way a lead acid battery is packaged. The chemistry is the same in all lead acid batteries.

[Chateau_Nomad]

Sounds like you've figured out WHAT you want to power... and you've got a good idea for how long.

Now all that's left is decide what your budget is. There are several ways to achieve what you want... each has trade offs.

I could tell you to put 400 watts of solar on your roof - with your low power requirements that would almost eliminate generator use. I could suggest you get two 100AH lithium batteries and the necessary peripherals to support those...

BUT I WON'T... because I don't know your budget. An honest assessment would be to start at bare minimum requirements... then work your way up, deciding if the gains are worth it FOR YOU. When someone tells you that you MUST have a certain setup, ask why... then decide if that makes sense... both functionally AND economically.

[16ACE27]

Originally Posted by Nightmare

I've been researching an upgrade to our RV power system. I'm still not sure what I want to do, after a visit to the local RV shop I'm in some sticker shock.

Unfortunately, lots of components will give you "sticker shock" today as compared to a year or 2 ago.

My system is a work in progress. My house batteries were brand new when I bought the coach so I milked them for 5 years of use. They're still good, one's the starter battery in my boat right now.

I started with a 2KW PSW inverter powered by 4 gauge wire through a 150 amp DC breaker. It is attached to a 15 amp Xantrex ATS to my TV outlet 120 VAC string which also has my network equipment on it.

I have a Renogy 500A Battery Monitor with shunt for my house batteries so I always know how much is going in/out and what their actual capacity is.

I have a simple voltage/current monitor on the dash for my chassis battery/alternator. It uses a Hall Effect Sensor Transformer for the current.
https://www.amazon.com/gp/product/B01JIK8J3C/


I recently replaced my house batteries with two 100 AH LiFePO4 batteries. Using the stock converter to charge them only keeps them charged to 68% to 80% capacity due to the FLA charging profile. This is fine when the MH is not being used but to get them to 100% before boondocking I installed a 20 amp charger in the battery bay which is controlled by a remote switch in the MH. At the push of a button I can allow this charger to pump them up to 100%. Much cheaper than buying a new converter with a Li charging profile.

But, if the house batteries are low they can stress the alternator to charge them through the BIRD/Trombetta so I installed a switch inside the MH and wired it to the Trombetta control wire to disable it if the house batteries are too low when driving, or when the house batteries are too high when stored: the BIRD will see the higher Li battery voltage as charging and keep the house and chassis batteries connected when they shouldn't be - so I can manually control that instead of replacing the BIRD/Trombetta with a Li-BIM at this point.

The Li-BIM will probably be the next step, and a Li converter after that.

[Bob Nodine]

If you are not an obsessed boondocker I would recommend you just install two 12 volt AGM batteries and plan to run the generator for 2 hours in the morning while you make breakfast, dry your hair, run the vacuum, etc. Run the generator again for 1 hour before quite time if necessary. As others have said it will be very expensive to modify your coach to the point where the generator will not need to be run each day. Your power budget will be the deciding factor. We have done a lot of boondocking over the years and most of the time we were in National Parks with considerable shade. For solar to be of any benefit you need to park in the sun. The downside to that, if you can find a campsite in the sun, is the internal temperature of your coach is going to be hot. A lot of folks spend copious amounts of money improving the power system in their RV because it is a hobby and a challenge. You be the judge of where you want to be.

And for the television just buy a dedicated inverter of about 600 watts and only run the television from it.

[Redsand]

I went through the same thought process months ago. My older rig had but one 12 FLA deep cycle for house use. My wife is a TV junkie so to make nice I had to build a 2nd platform to allow for a dual battery setup. I decided to keep things simple so I installed an inexpensive 300w inverter and wired it to a standard duplex outlet under the dinette seat with a lighted switch. I purchased 2 Renogy 100ah AGM batteries and ditched the Interstate FLA. Lastly I just finished installing the Renogy 500A Battery monitor to keep tabs on our usage. The upside is that it was relatively inexpensive compared to lithium but has it's limitations. I have to move the tv plug to the inverter outlet for boondocking. An extension cord if the bedroom TV is used. I know it's not ideal but as I mentioned simple and easy to upgrade if 300w is not enough. It's totally isolated from the coach electrical system which I like. So to summarize it all depends on your personal needs and how much you want to spend in labor and or cash.

[robertconley]

This I changed my Axis electrical grid.
Not cheap but had fun upgrading our BIG TOY.
1st added 3600 watt Rinology inverter.
2nd added a transfer switch
Wired the second transfer switch so: if shore power or generator power use that first for main power panel.

Without external power and inverter on, inverter is power source for the main panel.

3rd Now to eliminate 2 issues at the main panel. I have installed a if than connections, ( Schneider Electric/Legacy Relay 92S11A22D-120 Power Relay, Dpdt, 120VAC, 30A, ) in the main panel, for the airconditoning and the coverter charger circuits. This divice interrupts power to the airconditioner and the charger if it sees power from the inverter.
This makes it so neither can run if inverter is on.
Ok at this point you could stop.
When inverter is on everything 110 AC will work as long as your batteries last, except airconditioner and charger.
If you plug in or start generator AC will work and charger will recharge the batteries.

While driving the rv batteries will also charge.
My next step was where it gets expensive.
Added lithium 2 100amp, new charger, 400 watt solar, bmi.

I see this as to separate entities 1 inferstructure upgrade then techology upgrade to lithium.

[JeffThor325]

I have a dilemma that perhaps some of you smart people can help me with. Before I can get to the problem, I'm going to need to list some inventory so that you understand some parts of my system.

• Motorhome: 1995 Thor class A (the age is important)
• Rooftop Solar: 1,700W - in 4 separate circuits
• Wind turbine: 400W (occasional use only)
• Battery bank: 7x 100Ah AGM, plus 1x 55Ah AGM
• Battery bank wiring: mixture of 4AWG and 2AWG
• Inverter: 5,000W, wired directly to the battery bank
• Power center: Upgraded from original 30A to new WSCo 55A
• Shore power cord: still native 30A (with adapters for 15A and 50A)
• 2x rooftop air conditioners: both removed
• 4x rooftop vent fans: ~17W each
• Coach lighting: all but 1-2 light replaced with LED
• Refrigerator/freezer: 300W absorption (original equipment)
• TVs: none
• Computer: MacBook with 60W power supply

My generator hasn't even been started in at least two years. As far as I know, there's nothing actually wrong with it. (It is on my near-term project list to give it a good tune-up and see if I can make it run.)

Even if I could get the generator running, the solar battery bank is not connected to the coach's in-built electrical system in any way. It is 100% isolated.

So neither the generator nor the engine alternator will charge the solar battery bank. (I still have a FLA engine battery and FLA house battery.)

When traveling or boondocking, I simply plug the shore power cord into the inverter attached to the solar bank and it powers the entire coach. (I know this isn't the "right" way to do things. That's where the age comes into play. My coach is 27 years old. This was simply the most cost effective way to make things work without investing heavily in a coach that only has so much life left in it.)

Now for my dilemma:
Despite the fact that I have massively more solar than most RVs, and use a lot less power than most, the longest I have been able to go without plugging into shore power before the invert's low voltage alarm goes off is about 48 hours.

For the life of me, I've been struggling to figure out why.

[The_Dave]

Originally Posted by robertconley

This I changed my Axis electrical grid.
Not cheap but had fun upgrading our BIG TOY.
1st added 3600 watt Rinology inverter.
2nd added a transfer switch
Wired the second transfer switch so: if shore power or generator power use that first for main power panel.

Without external power and inverter on, inverter is power source for the main panel.

3rd Now to eliminate 2 issues at the main panel. I have installed a if than connections, ( Schneider Electric/Legacy Relay 92S11A22D-120 Power Relay, Dpdt, 120VAC, 30A, ) in the main panel, for the airconditoning and the coverter charger circuits. This divice interrupts power to the airconditioner and the charger if it sees power from the inverter.
This makes it so neither can run if inverter is on.
Ok at this point you could stop.
When inverter is on everything 110 AC will work as long as your batteries last, except airconditioner and charger.
If you plug in or start generator AC will work and charger will recharge the batteries.

While driving the rv batteries will also charge.
My next step was where it gets expensive.
Added lithium 2 100amp, new charger, 400 watt solar, bmi.

I see this as to separate entities 1 inferstructure upgrade then techology upgrade to lithium.

This sounds very close to what I want to do, the only addition would be solar to maintain batteries. That part of the system is fairly straight forward. Would it be possible to see a diagram of your system, maybe some pictures? Also, what transfer switch did you use? My main goal is to power the refer on 110 as we camp at high altitudes and the propane system will not run above 5500'.

Thanks!

[Nightmare]

That generator (I assume Onan) will probably need a new carburetor. Unless the older ones can actually be rebuilt.

I think I have a partial parts list for my RV.

I found a killer deal on a Renogy 170Ah LiFePO - $500
I plan to get a Victron Smart Shunt w/ Bluetooth - $130
I guess I need a Victron Charger IP6 15A w BT - $160

The battery is a little too big, I don't think I can fit 2 of them (it's about 1/2" too big) if I decide that 170AH isn't enough.

So I'll look for a portable Inverter and see how that goes in the near future.

[robertconley]

The transfer switch is:
Go Power! TS-30 30 Amp Automatic Transfer Switch , Black

I have uploaded the wiring diagram as well as a picture of the module.
Be careful.

[Nightmare]

Ok, so I picked up the battery. I have the Charger and Shunt arriving tonight.

The actual width of the Renogy 170 Ah is 13.6" or 13 5/8" wide.
The battery is a little bit wider at the top, only 13.25" wide at the base.

Width and Depth are not a problem. I think I could fit 2 in there, but it would be TIGHT and probably more battery than I need.


I knew the height of the battery was going to be an issue. The top raised section is just above the current step height.

BUT the Terminal Bolt is a full 1/2" too high. It seems like a VERY poor design to have the terminals be the highest point on the battery.

I ordered a battery box, but it won't arrive for my next trip. I think I will get a 1" wooden board and router out the location of the rectangle and terminals. It should only raise my middle step about 1".



And finally (for today), the terminal connections are 1/2". All the current rings are 3/8. I drilled one out to 1/2", but the ring seems a little thin. I guess I need to replace a couple of those. Probably just the 2 on the battery, I assume the Shunt has 3/8" connections.


There should be room in the battery box to mount the Shunt. Are there any issues with having those 2 in the same box/location?

[The_Dave]

Thanks! Let the games begin!!!

[tuchmybuttercups]

Originally Posted by Nightmare

I've been researching an upgrade to our RV power system. I'm still not sure what I want to do, after a visit to the local RV shop I'm in some sticker shock.

Our RV and the 'stock' equipment

2017 Thor Quantum GR22
- 2 of the Interstate 12V RV batteries (these are 100% shot, multiple dead cells)
- Onan 4KW Generator
- Whatever stock charger/converter that Thor installed (I'm sure it is cheap)
- 5100 Series Transfer Relay

I thought I would be able to just install a new Inverter next to the transfer relay, but the shop guy tells me that isn't the 'right way'. Sounds like they charge about $2,000 to install the inverter with a separate sub-panel (so the things I don't want the inverter to run are separate.

I planned to get a big AGM battery (200+ AH), but he tells me that it won't work much better than the Interstate 12v (discharge % and stuff like that).

They suggest either 6v Deep Cycle (which may not fit under the step) or go FULL SEND and get a Li Battery. Which requires a new Charger and possibly other upgrades.

I really don't think we will be boondocking for more than a week at a time. I mainly want the ability to run the TVs off the inverter. I guess I could just buy a portable inverter...

So what do you guys have? And if you are willing to share the cost.

Thanks

I've attached my electrical schematic for my system. My system is boondocking focused and, like you, I'm 'docking' for ~week before I need to dump/fill the tanks - and this setup works well for me.

-I first added 200Ahr of lithium as I needed the capacity and power output to start the generator. I also added a battery monitor.
-Since I switched from lead acid to lithium, I then needed to add a B2B charger and change the converter to properly charge the lithiums.
-I then added an inverter and swapped out any wiring that was going to be carrying high amps for it.
---I wanted my set up to automatically provide power to outlets/devices no matter what the source was (shore, generator, inverter) so I installed a second automatic transfer switch and added/switched around wires to enable. Internal schematic of that is on second page of attachment).
-Lastly, since the RV came prepped for 100W solar, I added a panel and swapped for an MPPT charge controller. Since I'm boondocking, I keep my energy usage minimal, and find the 100W does great to fight the system's parasitic draw and often creates enough to charge the batteries.

This setup allows me to use most things in the RV and keeps my batteries charged enough to get me through the week before I have to drive somewhere to dump the tanks (where then I'll be using the B2B to charge). Good luck on your upgrades and hope this helps on whatever you decide to do!

[Chateau_Nomad]

Originally Posted by Nightmare

Ok, so I picked up the battery. I have the Charger and Shunt arriving tonight.

The actual width of the Renogy 170 Ah is 13.6" or 13 5/8" wide.
The battery is a little bit wider at the top, only 13.25" wide at the base.

Width and Depth are not a problem. I think I could fit 2 in there, but it would be TIGHT and probably more battery than I need.


I knew the height of the battery was going to be an issue. The top raised section is just above the current step height.

BUT the Terminal Bolt is a full 1/2" too high. It seems like a VERY poor design to have the terminals be the highest point on the battery.

I ordered a battery box, but it won't arrive for my next trip. I think I will get a 1" wooden board and router out the location of the rectangle and terminals. It should only raise my middle step about 1".



And finally (for today), the terminal connections are 1/2". All the current rings are 3/8. I drilled one out to 1/2", but the ring seems a little thin. I guess I need to replace a couple of those. Probably just the 2 on the battery, I assume the Shunt has 3/8" connections.


There should be room in the battery box to mount the Shunt. Are there any issues with having those 2 in the same box/location?

I fit two 6v GC2 batteries under the steps on our class C by building a "riser frame" on top of the existing battery compartment. I had to remount the step hinges appropriately, but it works great. From memory, I believe the step is now about 3/4" higher... slightly noticable, but we adapted easily.

[Nightmare]

Originally Posted by tuchmybuttercups

I've attached my electrical schematic for my system. My system is boondocking focused and, like you, I'm 'docking' for ~week before I need to dump/fill the tanks - and this setup works well for me.

Thanks for that. I'm still dealing with a Chassis Battery problem. I can't tell if I have a dying battery and/or a small vampiric draw. Just sitting at the beach for a week and the RV wouldn't start. I was able to start the generator, so I used my Victron to charge the battery off the 110. So not too much of an issue.

I recently picked up a Renogy 100W Solar Suitcase. I just clipped the controller to the +BUS and the chassis. Seems to work fine according to the Victron Smart Shunt.

I would be nice to have everything installed a little cleaner, but I'm too cheap to pay the shop.

[tuchmybuttercups]

Originally Posted by Nightmare

Thanks for that. I'm still dealing with a Chassis Battery problem. I can't tell if I have a dying battery and/or a small vampiric draw. Just sitting at the beach for a week and the RV wouldn't start. I was able to start the generator, so I used my Victron to charge the battery off the 110. So not too much of an issue.

I recently picked up a Renogy 100W Solar Suitcase. I just clipped the controller to the +BUS and the chassis. Seems to work fine according to the Victron Smart Shunt.

I would be nice to have everything installed a little cleaner, but I'm too cheap to pay the shop.

Not sure where a parasitic draw would come from on the chassis battery. I would doubt any appliance is wired to that, but maybe worth checking. Also, if your chassis battery is lead acid, once you've gone past 50% charge you've now caused internal damage and degraded the performance of it. Is this why your battery is seems to have a parasitic draw? Dunno, maybe the internet can answer that.