RV electrical and solar system step by step - Step one, planning (What is your favorite energy monitor?)

[liveaxle]

I just moved into an older fifth wheel RV that was not built for off grid use. I am working to change that.

My current system is 2 RV/Marine Flooded Lead Acid Batteries, a converter, a basic DC system with some lights, a water pump and a Maxx-Air fan.

Long term, my plan is a battery bank that can power an inverter for AC systems, moving as many systems to DC as possible, and a charging setup that can charge from Solar, Grid AC power, a generator, and an upgraded alternator in my truck. Unfortunately, I can't afford to make all of these upgrades at once, but I have found a decent park to live in full time while I work, upgrade and prep for more of an adventure.

I would like to start with an inverter charger setup, because I am out in California and at the bare minimum, I would like to be able to roll over to my inverter in case we catch a blackout. My purchase plan is inverter/charger -> generator -> batteries -> alternator upgrade/connections -> solar. But I don't want to replace anything as I build on.

But before I can buy anything, I need to know how much power my system is using.

Any suggestions for an energy monitor to properly start sizing my system for my 50 amp 5th Wheel (w/2 air cons, but I don't plan to run them on batteries).

Also, I am planning to use a hybrid inverter so I can live life as normal when connected to a 30 amp or 15 amp 110v outlet (including at least one air con). How should I consider that in my sizing plans?

 

[FilterGuy]

Any suggestions for an energy monitor to properly start sizing my system for my 50 amp 5th Wheel (w/2 air cons, but I don't plan to run them on batteries).

IMHO A kill-a-watt is a must. You can use that to measure the actual usage of an AC appliance over time.

Next, a good clamp-on Amp/Volt/Ohm meter. You can use this to measure Volts and Amps of a DC circuit and the use Watts law to determine watts being used P=IV. Fluke is a great brand but expensive. Will recommends the Klein on his tools page (https://www.mobile-solarpower.com/tools.html )

Finally, a State-Of-Charge meter would be good to install. The Victron one is great but expensive. The Aili is a lot more affordable, but it probably would not keep an accurate SOC of your Lead-acid. It would give you good instantaneous Watt usage though.

One thing you should do is an energy audit. Check out my signiture to a energy audit tool I put into the resources.

Finally: Two ACs is a LOT to drive from batteries. Most folks find it is impractical. You should figure out what that is going to take very early in the process so you don't under-buy components.

 

[liveaxle]

I don't plan to drive any air con completely from batteries, but I would like to be able to run one over a hybrid inverter when connected to a 110v 15amp outlet.

 

[liveaxle]

Note: I am using air con to avoid accidentally mixing the A/C appliance with the AC current. I'm not sure if it will work long term, but I'm trying.

 

[Pappion]

I estimated my old Camper and my new TT 12v loads , and the amount of time used. Time is so variable, no point in being precise. I stated with the heavy hitters: Furnace Blower: 3.5A and 7A TT, 5hrs and 3hrs in AZ winter. Water heater when running 1A, Frig when running on propane 3A etc... Biggest option is my Gaming Laptop, typically 45W to 70W, 90W max

 

[willo]

I love my BMV-712, simple, bluetooth app works great. Completely worth the $200 IMO. Easy to check status when I'm at the camper control center.

 

[FilterGuy]

I love my BMV-712, simple, bluetooth app works great. Completely worth the $200 IMO. Easy to check status when I'm at the camper control center.

It is a great product! No doubt about that!! The Victron BMV-712 is definitly superior to the Aili but I was trying to give alternatives.

 

[Rocketman]

If you are thinking of Victron (I recommend it and use it) - know they are a premium products - usually with premium features and $$$. Look at the end game with Victron - pull up some youtube video's using their CCGX (older) or crebo GX (newer) products. The data management of the electrical system in my RV was worth the price to me.

Assuming you decide to go ahead on the Victron path - here are a few initial things to be aware of:

Decide on where the GX device will be located. CCGX - in the living area or Cerbo in the mechanical area (w/ touch50 in living area)

Shunts: BMV-712 vs SmartShunt. You will need to connect a VE.Direct cable from the Display of 712 to GX, or the SmartShunt to GX. This could help make the choice between the two of them - otherwise they are very close except no display for SmartShunt. (I use my iphone with the Bluetooth for 99% of the time on my BMV-712 - in fact it is not attached to the wall - just on the bottom of the shelf - I find my iphone easier to use the data than the display module).

Now use the battery monitor (BMV712 or SmartShunt) to help get a good idea of your loads and your total usage.

Next Steps:

Multiplus Inverter/Charger: When you buy this you will need to control it. I control mine with the CCGX, I think that is easier than the dedicated control panel.

Solar - The SmartSolar units are very nice with the data you get on your phone.

To give you an idea - my MotorHome:
BMV-712
Solar Panels 800w (4-200w panels)
SmartSolar 100/50
Multiplus 12v/3000 Inverter /Charger
Currently 400ah of Lead-Acid - will be moving to 500ah of lithium this spring.
(We have a generator - but do not use it much - unless parked in the trees - even then <2hrs in 2 days.

My purchase plan was: BMV ->Solar -> inverter/charger & CCGX -> (Future) Lithium batteries. (Generator already included in Rig).
I would put solar ahead of new alternator.

 

[floydo]

Just to add another resource, I have used this meter for years and it works very well as a clamp on and is also true rms...

Amazon.com

 

[Pappion]

Smart Solar works with BMV-712 or Smart Shunt current and voltage data. It knows if the current is going to the batteries or load. The remote voltage sense is a good feature too.
I have Smart Solar 100/50 and Smart Sense joined in a network. I have used them to estimate my DC current loads.

 

[willo]

I gotta add a little more to the pot. I added a raspberry pi with a victron image, now I have stats on everything via their VRM portal. I'm going to add a local graphana instance, but with my camper stored a ways down the mountain from me, it's fantastic for monitoring my gear and charge state. Currently I'm getting data from my mulitplus, my solar controller, and soon my BMV - just need to extend some cabling for that.

 

[Flourman]

My first camper energy monitor started with the cheap meters off Amazon. I had one one shunt on the charge line and one on the consume side. Simple but it required resetting the numbers everyday. This was when I was a total solar newb.

When we upgraded campers, I went from the cheaper stuff and added the Renogy Adventurer controller and Renogy’s battery monitor. They work OK. But now I’m jumping up to the Victron Bluetooth unit. I can pull the controller in on Bluetooth now so adding the another battery monitor on Bluetooth is more for piece of mind. Basically so I can lay in bed, pull up my phone and see where my batteries are as that’s my number one anxiety driver when off-grid.


I used the battery monitor and ran each piece of 12VDC thing in the camper to give me an idea of what I’m using without looking. I run two 6V lead acid batteries in series and 200W fixed plus another 200W mobile of solar.
.

 

[HaldorEE]

Shunts: BMV-712 vs SmartShunt. You will need to connect a VE.Direct cable from the Display of 712 to GX, or the SmartShunt to GX. This could help make the choice between the two of them - otherwise they are very close except no display for SmartShunt. (I use my iphone with the Bluetooth for 99% of the time on my BMV-712 - in fact it is not attached to the wall - just on the bottom of the shelf - I find my iphone easier to use the data than the display module).

Now use the battery monitor (BMV712 or SmartShunt) to help get a good idea of your loads and your total usage.

One additional comment. The BM-712 has a relay output you can use to notify you that the cells are getting close to then end of their charge life. Or you can use it to turn off a dumb inverter or charger at either end of SOC, so the battery BMS doesn't get have to get involved in the daily charge/discharge cycle.

 

[liveaxle]

I just purchased a Victron Smartshunt. I like that I can check it from my phone and that there is a Linux app (even if not officially supported). Eventually I plan to use build a home automation suite, and I am hoping the Victron App will be useful for that. Even if I can't it should work for planning, and right now I am leaning toward a Victron MultiPlus.