On to improvements

[Flyinhy]

Hi guys,

Hope everyone is doing well. I'm pretty much done with the major repairs on the Exec. It's time now to start planning my improvements. I know I've read other posts on adding  batteries and charging options. I'm considering building a battery bank in my rear closet. It's directly over the battery compartment too. I currently only have 2 12v lead acid batteries running the Samsung fridge on trips and the charge only lasts about 2 hours before I have to crank the generator. I just wanted to get some ideas on what kind of systems you guys have and how long you can run without starting your generator. I only have one flat fixed solar panel but I have plenty of room to add 3 more of the same size. 

[jacwjames]

I'd check the size of your battery tray and see if you can fit four 6 volt batteries in, (I'd be surprised if you couldn't).  You could opt to go with the better AGM type higher capacity. 

I have four 6 volt flooded type and can easily go over night without a problem, I have a RF18 Samsung.   I do have 325 watt of solar.   On a good sunny day I only have to run the generator ~1 hour before bed. 

[vito.a]

I'm using four Trojan 6v T105 batteries. They easily support our Samsung Fridge overnight.

Watch some of the Will Prowse videos on YouTube.  I'm going to eventually build my own Lithium battery bank.  

[Rocketman3]

I have six 200watt solar panels and a 500ah of 12v lithium (self built battery).  If the sun is out - no need for the generator- if it gets cloudy for two days - the generator needed the exercise anyway. 
 

The solar is awesome!  We prefer to boondock so that’s why we have that size of array. 

Edited February 12, 2022 by Rocketman3

[CAT Stephen]

1 hour ago, Flyinhy said:

Hi guys,

Hope everyone is doing well. I'm pretty much done with the major repairs on the Exec. It's time now to start planning my improvements. I know I've read other posts on adding  batteries and charging options. I'm considering building a battery bank in my rear closet. It's directly over the battery compartment too. I currently only have 2 12v lead acid batteries running the Samsung fridge on trips and the charge only lasts about 2 hours before I have to crank the generator. I just wanted to get some ideas on what kind of systems you guys have and how long you can run without starting your generator. I only have one flat fixed solar panel but I have plenty of room to add 3 more of the same size. 

To size a new battery solution properly along with potential additional solar, please provide the following information:

- What is your average kwh consumption per day specific for your coach? (If you don't already have a shunt, you can buy a "cheap" shunt for ~$20 to get this information)

- What are the type and capacity of your current house batteries? (AGM/Flooded/Gel/Lithium, specify capacity in amp-hours)

- Is your refrigerator 120VAC running off your inverter, a 12V Compressor refrigerator, or a propane/12VDC Gas Absorption refrigerator?

- What is your inverter make and model number (to determine LiPO4 compatibility)?

- What is the rated output of your current solar panel in watts?

- What is your "primary" RV usage location (this can vastly impact solar generation and is a factor if you select lithium)? 

- What is your primary season that you use your RV (this vastly impacts solar generation)

- What is the manufacturer and model number of your solar controller?

- What is your use case? (near full time on grid / near full time off grid / %on & %off grid if mixed

Also be advised that placing batteries inside your coach can be very hazardous.  Lithium LIPO4 can leak very toxic chemicals if the case or cell(s) are mechanically compromised (this is rare). LiPO4 is if the safest of all options due to the BMS.  AGM and SLA variants can under certain circumstances vent explosive hydrogen gas inside of your coach (explosion hazard).  Flooded is not an option inside your coach.

For $20, you can precisely know your kwh daily power consumption before investing $100s/$1000s on new batteries, solar and other electrical equipment.

Everyone has a unique use case for electrical loads.

 

[Gary Cole]

That is an excellent summary Stephen. I did a similar analysis and discovered that it would be cheaper for me to run the generator rather than invest a large sum in solar panels and lithium batteries. Given the time I spend off grid I would never amortize the investment. I do have 675 watts of solar power which has proven to be cost effective in the long term given the reasonable investment.

[Ivylog]

My question is how many days/ year are you going to dry camp?

One good 12V battery should run your Samsung 12+ hours and it doesn’t care if the inverter is a MSW or PSW inverter… it’s compressor is a DC motor. It only draws 1 amp 120V AC when running aprox 40% of the time which works out to 1.2 KW/day which at home costs 16-18 cents/day. Also while driving, the alternator should be charging the house batteries. 
 

Unless you do a lot of dry camping, spending lots of  $$$ on solar and Lithium’s is a waste of money…run your generator a couple hours/day to change your batteries. 

I  DIYed 1000watts of solar ($1200) and 600 AH of Lithium ($1200) and even dry camping 5-6 days/week in the summer (50 days) my payback is 10+ years. 
 

 

[Flyinhy]

1 hour ago, Ivylog said:

My question is how many days/ year are you going to dry camp?

One good 12V battery should run your Samsung 12+ hours and it doesn’t care if the inverter is a MSW or PSW inverter… it’s compressor is a DC motor. It only draws 1 amp 120V AC when running aprox 40% of the time which works out to 1.2 KW/day which at home costs 16-18 cents/day. Also while driving, the alternator should be charging the house batteries. 
 

Unless you do a lot of dry camping, spending lots of  $$$ on solar and Lithium’s is a waste of money…run your generator a couple hours/day to change your batteries. 

I  DIYed 1000watts of solar ($1200) and 600 AH of Lithium ($1200) and even dry camping 5-6 days/week in the summer (50 days) my payback is 10+ years. 
 

 

That's about the length of time I'm looking for . After reading past posts I know I need to switch to the ML- ACR instead of the original components or something similar because it's not charging like it's supposed to. I know absolutely nothing about solar. I need to do a LOT more research.

[Ivylog]

Didn’t answer how many days dry camping you expect to do??? One fallacy of solar, unless you are FTime, is in the summer I search out shade and elevation so I do not need to run the AC to keep cool. Instead of getting 70+ amps charging from my 1000W of solar ( only at noon with the panels  tilted) I’ll only get 15-20 amps in the shade at high noon. This is not enough to keep up with our power needs and why my solar is more a feel good situation than actually being cost effective. 

[Chuck B 2004 Windsor]

Installation of ANY type of battery bank in the closet of your coach can be hazardous to the health of all people in your coach.  Battery banks need to be surrounded by outside air.  

[jacwjames]

I've got 325 watt solar, even on good days I'm lucky to see 15 amp charging, but still better then nothing. 

I've looked at adding more solar but in my head I just can't justify it, the pay back just isn't there when you consider the cost of upgrading my current system.  New controller, solar panels, and more (or improved) batteries.  Haven't priced everything out but ~$2000 or more.  Current diesel prices could buy 500 gallons of fuel or 1000 generator hours.  We've had our coach 13 years and haven't put 1000 hours on the generator.  And even if we upgraded we'd still have to run the generator if it's hot out for AC, or it's raining, or we want to run the microwave/coffee maker etc.   There is a slight savings generator maintenance but not enough to worry about.  

I guess if we full timed and boon docked a lot it would be another story.  For us it just doesn't make sense. 

[Flyinhy]

2 hours ago, Ivylog said:

Didn’t answer how many days dry camping you expect to do??? One fallacy of solar, unless you are FTime, is in the summer I search out shade and elevation so I do not need to run the AC to keep cool. Instead of getting 70+ amps charging from my 1000W of solar ( only at noon with the panels  tilted) I’ll only get 15-20 amps in the shade at high noon. This is not enough to keep up with our power needs and why my solar is more a feel good situation than actually being cost effective. 

I'd like to be able to run a few things overnight or a  day if I had to without cranking the generator. 

 

1 hour ago, Chuck B 2004 Windsor said:

Installation of ANY type of battery bank in the closet of your coach can be hazardous to the health of all people in your coach.  Battery banks need to be surrounded by outside air.  

This is the compartment I was talking about....it's in the rear closet but it could be vented to the outside. I could fit several batteries in there. Roughly  2' x 2'

Edited February 12, 2022 by Flyinhy
Added content

[Ivan K]

Our theoretically 1000w rated array with Victron 75/150, 4 wett batteries, maybe 2k investment paid off in my view when we lost the generator with 3 months left on a trip last year. Mostly dry camped a week or even two between 1 night FHU stays for dump and laundry, moving with the weather between BLM, forests and some SPs, out west. It was near impossible to get last minute reservations and the solar saved our bacon. Certainly not a usual situation but when the apocalypse comes, we have a chance 😂, I don't feel we wasted any $$$ on it and would do it again. Just get the right controller the first time so it can be scaled up for reasonably cheap.

[jacwjames]

1 hour ago, Flyinhy said:

I'd like to be able to run a few things overnight or a  day if I had to without cranking the generator. 

 

This is the compartment I was talking about....it's in the rear closet but it could be vented to the outside. I could fit several batteries in there. Roughly  2' x 2'

I think the single solar panel you have is 85 watt, barely enough to take care of the parasitic draw.

If you add solar panels you'd be bettor off removing that one and using all the same, from what I read it's not the best practice to mix and match. 

I think if you look at the spec's you'd be better off replacing your two 12 volt with four 6 volt, you would end up with more amp hours to run off of. 

23 minutes ago, Ivan K said:

I don't feel we wasted any $$$ on it and would do it again. Just get the right controller the first time so it can be scaled up for reasonably cheap.

My problem is that the controller I have is the old Helitrope, so I'd have to replace that along with the panels.  These were all on the rig when I got it.

I agree, do it right the first time and if I end up redoing mine I'll do exactly that.

[Ivan K]

I know that a number of us left the factory solar in place and only use it for chassis batteries. I relocated the panel for better roof arrangement and moved the controller's chassis battery leads to previous house output terminal to give it proper charging sequence instead of a permanent voltage. Can't tell if it makes a difference but made sense to me.

[Ivylog]

I would go to two 12V AGM batteries, replacing what you have to start… may be all the AH you need. IF you decide you need more AH then add them to the box in your picture.
You can add up to 3 more 100W solar panels to the one you already have using the current 30 amp controller. No it’s not very efficient, but good enough for what you’re trying to do.