2021 351MS Momentum factory electric system upgrade Solar power ideas

[bo619]

I got 2021 351 MS Momentum, would like to consider DIY adding more solar powers to existing factory system with Lithium Upgrade with Minimal Change, such as replacing existing 300 watt solar panel with 1000 watt panels, replacing existing 2X6v acid deep circle batteries with 600 to 800 ah lithium batteries, etc. in order to run more devices or be able to spend more time boondocking. My big concern is: what are the maximum solar panels and lithium batteries that can be added or replaced so that I don't need to touch or change the factory installed shore power and generator components in order not to mess up the existing electrical system? Thanks

 

[Soundsailor]

What are the goals of your upgrade? The first step to consider is what are your needs. There's a good post in the solar forum on planning your system, that would be a good place to start.

 

[bo619]

Hello
Thanks for your reply. What are the goals of my upgrade?
1> solar power goal: my current system can only support lights and fans 24/7. Short term goal is to enable heavy use of the internal led lights, fridge 24 hours for a couple of days and plus light use of TV and laptop PC for 3-4 hours a day after battery is fully charged; long term goal: hope the system can help run lights, fans, fridge 24/7 (although I can use propane for fridge, I prefer using electric as much as possible) plus TV and PC for 3-4 hours per day and system is expandable for more power need.
2> Financial goal: I hope I can do most of the job or all the installation job to financially help me save labor cost if the system re-configuration does not need supper professional technical skill under clear instructions. That is why I was wondering if I don't have to touch and change anything on the shore power and generator components, wirings (I have no experience on these so far) in hope that I can simply change batteries, solar panels, wiring between panel and controllers so the existing shore power and generator will automatically support charging the new battery banks without any issue.

 

[Bungy]

Hello
Thanks for your reply. What are the goals of my upgrade?
1> solar power goal: my current system can only support lights and fans 24/7. Short term goal is to enable heavy use of the internal led lights, fridge 24 hours for a couple of days and plus light use of TV and laptop PC for 3-4 hours a day after battery is fully charged; long term goal: hope the system can help run lights, fans, fridge 24/7 (although I can use propane for fridge, I prefer using electric as much as possible) plus TV and PC for 3-4 hours per day and system is expandable for more power need.
2> Financial goal: I hope I can do most of the job or all the installation job to financially help me save labor cost if the system re-configuration does not need supper professional technical skill under clear instructions. That is why I was wondering if I don't have to touch and change anything on the shore power and generator components, wirings (I have no experience on these so far) in hope that I can simply change batteries, solar panels, wiring between panel and controllers so the existing shore power and generator will automatically support charging the new battery banks without any issue.

I’m no expert but I don’t think upgrading the solar will impact the shore power or generator systems at all.

 

[Soundsailor]

solar power goal: my current system can only support lights and fans 24/7. Short term goal is to enable heavy use of the internal led lights, fridge 24 hours for a couple of days and plus light use of TV and laptop PC for 3-4 hours a day after battery is fully charged; long term goal: hope the system can help run lights, fans, fridge 24/7 (although I can use propane for fridge, I prefer using electric as much as possible) plus TV and PC for 3-4 hours per day and system is expandable for more power need.

OK, lights and fans don't use much power so we'll skip those for now. It sounds like your frig is the dual fuel variety, let's assume that it draws about 5 Amps when running on electric. The TV and laptop charging won't use that much. Do you have an inverter? You'll need one to run your AC-using components such as the frig, TV, charger, coffee pot, etc. Let's say that with the inverter running, you will draw an average of 6 Amps per hour. Over a day that is 144 Ah (Amp hours - 6 * 24). So between your solar panels and battery storage, you'll need about 150 Ah for every day you'll be off-grid. I'd suggest at least 300 Ah of LiFePo4 batteries (2 days).

You say you have 300 watts of solar currently. With good sun, that should produce in the neighborhood of 25 Amps per hour. Let's estimate a total of 150 Ah per day (assuming 6 hours of good sun). For now, you may find the existing panels are enough. I'd start with the batteries and see how much power you use before adding anything else.

What kind of solar controller do you have? If it is the Furrion that comes stock on many GD coaches, you might consider upgrading to a Victron, much more reliable and gives a lot of useful information on how it is performing. A must is a shunt-based battery monitor, again the Victrons are the best. The shunt will tell you how much power you have available in your batteries.

 

[bo619]

OK, lights and fans don't use much power so we'll skip those for now. It sounds like your frig is the dual fuel variety, let's assume that it draws about 5 Amps when running on electric. The TV and laptop charging won't use that much. Do you have an inverter? You'll need one to run your AC-using components such as the frig, TV, charger, coffee pot, etc. Let's say that with the inverter running, you will draw an average of 6 Amps per hour. Over a day that is 144 Ah (Amp hours - 6 * 24). So between your solar panels and battery storage, you'll need about 150 Ah for every day you'll be off-grid. I'd suggest at least 300 Ah of LiFePo4 batteries (2 days).

You say you have 300 watts of solar currently. With good sun, that should produce in the neighborhood of 25 Amps per hour. Let's estimate a total of 150 Ah per day (assuming 6 hours of good sun). For now, you may find the existing panels are enough. I'd start with the batteries and see how much power you use before adding anything else.

What kind of solar controller do you have? If it is the Furrion that comes stock on many GD coaches, you might consider upgrading to a Victron, much more reliable and gives a lot of useful information on how it is performing. A must is a shunt-based battery monitor, again the Victrons are the best. The shunt will tell you how much power you have available in your batteries.

Hi
Thanks for providing such detailed information. I will consider starting with one or two 300 Ah LiFePo4 batteries to see how it works.
Yes, the existing system includes a 2000 inverter and a 30 amp basic charge controller, I will take your advice, upgrading to a Victron (maybe 40 or 60 amp?) and a shunt-based battery monitor.
I think I can follow all the instructions and install all these by myself. As for the existing shore power and generator components, I think it it is better not to touch it if the planned upgrade works well when they are done.
Thanks again for your help!
Warm regards
Bo

 

[Soundsailor]

Happy to help, let us know how your project turns out. Pictures are good, you may help someone else who wants to do the same upgrade.

 

[SolarPoweredRV]

Hello
Thanks for your reply. What are the goals of my upgrade?
1> solar power goal: my current system can only support lights and fans 24/7. Short term goal is to enable heavy use of the internal led lights, fridge 24 hours for a couple of days and plus light use of TV and laptop PC for 3-4 hours a day after battery is fully charged; long term goal: hope the system can help run lights, fans, fridge 24/7 (although I can use propane for fridge, I prefer using electric as much as possible) plus TV and PC for 3-4 hours per day and system is expandable for more power need.
2> Financial goal: I hope I can do most of the job or all the installation job to financially help me save labor cost if the system re-configuration does not need supper professional technical skill under clear instructions. That is why I was wondering if I don't have to touch and change anything on the shore power and generator components, wirings (I have no experience on these so far) in hope that I can simply change batteries, solar panels, wiring between panel and controllers so the existing shore power and generator will automatically support charging the new battery banks without any issue.

Good goals: I am not sure about your refrigerator expectations and powering it with Electricity. Here is why: if you have a Propane refrigerator and you run it off of Electricity, it operates with a resistive heating element. Resistive heating is very power hungry and could easily drain your 600ah battery bank in 4 to 6 hours. The good news is; that you have a Propane refrigerator, and that eliminates one of the biggest electrical draws upon your Solar and Battery system. Running your fridge on Propane is really very efficient.

When you upgrade your Solar panels, I recommend using Residential panels. You will need to be aware of the wire gauge the OEM used for the cables, however, this should not be much of an issue if you combine your panels in Series and Parallel to increase the voltage being fed to the Solar Charge Controller.

I second the recommendation to replace the Solar Charge Controller with Victron equipment.

With 600ah of batteries and your usage, as described, you should have no problem boondocking for weeks on end as long as you have decent sunshine.

To get a really good overview of installing your solar system, read the following thread:

Affordable Solar -- How to Design and Install an Affordable Solar System