RV Solar Install - Need Help

[Naruto]

I recently purchased a Class A motorhome and installed solar myself. Continuing to run into trouble, most issues sorted out, but latest issue is I can only run everything for about an hour before the batteries are drained(I am sure I will need more batteries, but do not know how much).

I included a picture of how everything is currently wired. Let me know if I should change this or not.

 

Currently trying to power

l General electronics

Ø TV, Lights, Cell Phone Chargers

 

l RV refrigerator

Ø Norcold - NA7LX

Ø https://www.campingworld.com/norcold-polar-7lx-refrigerator-7-cu.-ft.-2-way-right-swing-door-na7lxr-112694.html?utm_source=google&utm_medium=ppc&utm_campaign=%7bCampaign%7d&gclid=CjwKCAjwtfqKBhBoEiwAZuesiMgyflbIYMGTj2f8oXo4IXT8o7r_PyhaxLRNR4KcoMTGcc7QJeBTZxoC6R8QAvD_BwE&gclsrc=aw.ds

l Portable A/C - Keystone KSTAP07PHA

Ø 10,000 BTU

Ø 11.5 amps

Ø 115 Volts

Ø https://www.homedepot.com/p/Keystone-7000-BTU-DOE-10000-BTU-ASHRAE-115V-Portable-Air-Conditioner-KSTAP07PHA-with-Remote-for-up-to-300-sq-ft-in-White-KSTAP07PHA/317955262

 

Below is the current setup I have.

 

Solar Panels Total - 6

 

2x Newpowa 210W(Watt) Solar Panel Monocrystalline 12V - https://www.amazon.com/gp/product/B00ZIZ6VY6/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

 

4x Renogy 200 Watt 12 Volt Monocrystalline Solar Panel - https://www.amazon.com/gp/product/B08CRJYJ22/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

Go Power! TS-30 30 Amp Automatic Transfer Switch - https://www.amazon.com/gp/product/B00153EYTO/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

 

Eco Worthy - 3500W Off Grid Pure Sine Wave Inverter 12V/24V/48V to 110V - Bought the 24v version - https://www.eco-worthy.com/collections/components-batteries/products/3500w-off-grid-pure-sine-wave-inverter-12v-24v-48v-to-110v

 

Eco Worthy - 60A PWM LCD Display Solar Charge Controller Regulator 12V/24V Autoswitch - (Similar model, terrible company, doesn't show my exact model) - 60A PWM LCD Display Solar Charge Controller Regulator 12V/24V Autoswitch https://www.eco-worthy.com/collections/components-batteries/products/20a-30a-pwm-lcd-display-solar-charge-controller-regulator-with-usb-port-12v-24v-autoswitch

 

3x - Eco Worthy - 100Ah 12V AGM Deep Cycle Battery - https://www.eco-worthy.com/collections/components-batteries/products/100ah-12v-agm-deep-cycle-battery

 

1x - Mighty Max 12 Volt 75 AH SLA Battery - https://www.amazon.com/Mighty-Max-Battery-Internal-Product/dp/B01HBU3AVW/ref=asc_df_B01HBU3AVW/?tag=hyprod-20&linkCode=df0&hvadid=507755833368&hvpos=&hvnetw=g&hvrand=12790711838582703051&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9028163&hvtargid=pla-1257028926402&psc=1

[Chad Heiser]

The first thing I see is you can’t mix batteries of different ratings like that.  The lower rated battery will affect the ratings of the larger battery.  Also, if your batteries are actually wired the way your diagram shows, you have some voltage issues as well.  

You can’t mix two differently rated 12 volt batteries into a 24 volt bank like that.  If that is the way your batteries are truly wired, I’m surprised you haven’t fried something.  You need to take the third 100 ah 12 volt battery and the 70 ah 12 volt battery out of the system.  

If you want to increase the size of your 24 volt battery bank you need a fourth of the 12 volt 100 amp hour gel batteries and it needs to be wired in series with the third battery.  That series pair then needs to be wired in parallel with the first series pair.  Your positive and negative connections for your components then need to go between the positive terminal of the first series pair and the negative terminal of the second series pair so the batteries are used more uniformly.  

Finally, I assume the rest of your coach is 12 volt (like lights, RV fridge, jacks, RV water heater, slides, etc.), so you need some way to step back down to 12 volt from the 24 volt battery bank to run those items.  This is usually accomplished with a 24 volt DC to 12 volt DC converter.  It can also be done by running a separate 12 volt battery bank Independant of the 24 volt bank to run your 12 volt appliances, leaving the 24 volt bank just to power your inverter.  Of course doing that requires two separate charging systems, one 12 volt and one 24 volt.

[lappir]

5 hours ago, Chad Heiser said:

The first thing I see is you can’t mix batteries of different ratings like that.  The lower rated battery will affect the ratings of the larger battery.  Also, if your batteries are actually wired the way your diagram shows, you have some voltage issues as well.  

You can’t mix two differently rated 12 volt batteries into a 24 volt bank like that.  If that is the way your batteries are truly wired, I’m surprised you haven’t fried something.  You need to take the third 100 ah 12 volt battery and the 70 ah 12 volt battery out of the system.  

If you want to increase the size of your 24 volt battery bank you need a fourth of the 12 volt 100 amp hour gel batteries and it needs to be wired in series with the third battery.  That series pair then needs to be wired in parallel with the first series pair.  Your positive and negative connections for your components then need to go between the positive terminal of the first series pair and the negative terminal of the second series pair so the batteries are used more uniformly.  

Finally, I assume the rest of your coach is 12 volt (like lights, RV fridge, jacks, RV water heater, slides, etc.), so you need some way to step back down to 12 volt from the 24 volt battery bank to run those items.  This is usually accomplished with a 24 volt DC to 12 volt DC converter.  It can also be done by running a separate 12 volt battery bank Independant of the 24 volt bank to run your 12 volt appliances, leaving the 24 volt bank just to power your inverter.  Of course doing that requires two separate charging systems, one 12 volt and one 24 volt.

I didn't read or look at the photos of the initial post, but I do understand what Chad is saying and why I will never attempt Solar without a qualified person who will review my plans and supervise any of my actions. 

Better yet would be a plug and play system that I only need to find space to install and plug in color coded harnesses. All the necessary equipment would be   mounted   on a durable panel with the wires attached, the batteries grouped in manageable sizes and could be added as needed when additional power was required, but also removed if needed for service, repair or replacement and not affect the critical power needs (IE Fridge and coffee maker) . 

I have a full roof of space for panels and one day I will do it. 

 

Rod

[Chad Heiser]

16 hours ago, lappir said:

 

I have a full roof of space for panels and one day I will do it. 

 

Rod

Let me know when your ready Rod. 😉

[podwerkz]

Power your fridge with propane.

Don't try to run an A/C unit on this system, it has it's limits.

Doing these two things, you might be able to make the rest of it work.

 

 

[Rahim]

A solar panel on your RV is a good investment. RV solar panel installation is an easy project for anyone with basic electrical wiring knowledge. You can get further information on this website. 

A 10 watt panel, which can often be found at discount retailers, will generate about 100 watts of electricity per day. That's enough to make 9+ amp hours of energy per day without needing any other power sources! But you'll need to strategically place it for the best efficiency results - make sure the sun hits it during most hours of the day - and keep your batteries charged up.

[Mr Gilbert]

The Class A motorhomes I'm familiar with all had house batteries, charging from the chassis engine, and an inverter/charger.  It appears you built yours from scratch, and that's a puzzle to me.  While not optimum, I think you have a start on your system.  You've already made a significant investment.  

It appears from your wiring diagram that the batteries are providing 12 volts (nominal) to a 24 volt inverter.  This is a significant mismatch.  I suggest replacing your 24 volt inverter with a 12 volt inverter.  

I agree with the comment above that it isn't optimal to mix and match batteries, but I've done it and if they connected in parallel (as shown in your diagram) the system will work and all the batteries will store power for you. 

I agree with the comment above that it is better to power the refrigerator with propane, when not on shore power.  

It appears that you have no charging system other than solar.  I suggest connecting the chassis 12 volt power to the added coach batteries so that the batteries are charged when the engine is running; this will take expertise.  Also, I suggest using a battery charger to charge the batteries while connected to shore power.  Better yet, get a combo inverter/charger when you replace your inverter.  

Running an air conditioner off batteries and solar is a dream for many and an accomplishment for very few. 

[franco-bolli]

I saw an article in Handyman Magazine Sept 22

Here is their method of calculating.
"RIGHT SIZE YOUR BATTERY BANK"

List all AC loads in Watts (W) in a table and calculate the total watt-hours (Wh) per day. ( this should also work for DC loads, loosely watts are watts)
Multiply that number by the days of Autonomy(DoA), that is the number of days you expect to have complete cloud cover (read very little charging).
Divide that number by the voltage of the system. This is the amp-hours (Ah) your battery bank should have.

Below is an example of determining battery size

AC LOAD W X Hrs per day = Wh per day

Wh per day X DoA = Total Wh

Example:
Television 132W x 2 (hrs/day) = 264 Wh

ventilation fans 50W x 2 (hrs/day) = 100Wh

LED Lights 15W x 2 (hrs/day) = 30Wh
---
Finding the total Watt hours
264 + 100 + 30 = 394 Wh

Total = 394Wh per day x 3 (days of Autonomy) = 1182Wh
---
Finding the necessary Amp hours
1182Wh / 12V = 98.5Ah
---

If  a battery is 100Ah, it appears that it would be dead in about 3 days of this load, or whatever cut off is, if there is minimal charging.

Hypothetical string of LED's around the trailer. (wattage used is a complete guess below)

LED light string 15W at 8 hours / night

15W * 8 h = 120Wh

3 days of LED string use but complete cloud cover (minimal charging)
3 * 120W = 360Wh

Amp hours needed to light the lights for 3 consecutive, 8 hour days without charging.

360Wh / 12V = 30Ah

BTW, Don't shoot the messenger!! I'm just copying the information from Handyman Magazine, Sept 22 edition page 54. The part for your specific application was what I added to the information from Handyman Magazine.

I went to this web site https://www.omnicalculator.com/ecology/solar-panel
and used some input based on the information above.

If you choose to visit you can plug in your own values but here's what I did..

I presumed that total usage of the LED string with 5 hours of charging a day(if you are in the lower latitudes!) for a month would be 3.6kW. Which is 120Wh * 30 days.

I set the "bill offset" to be 100% to make the calculator believe that I wanted to run autonomously or the solar to be paying the whole bill.

I used a 70% environmental factor to presume the Solar panel was a little dirty.

The answer was that I needed a 30 W array.

I am not a solar expert! I just using the tools available to help figure out what's needed.

Hope this helps.
(My fire resistant is suit on, I'm sure there will be some discussion about the calculations)