Problem Solving Thread as I put together Solar/12v system for Camper Van

FarmerFrederico

Adventurer
Hi Everyone,

I've got a 2010 Ford E350 V10 with the factory auxiliary batter setup. Here is a little info about that system that Redoval shared with me:
• 155AMP Alternator
• ONE 78 AMP battery (main) and ONE 75 AMP battery (auxilliary) both original to the vehicle.
• The battery IS isolated from the main battery when the key is off.
• Group 65 for BOTH of my Batteries.
• The Aux Battery Box on the frame rail must be shorter than 6.5” tall with the posts.
• Aux battery powers the trailer battery relay when the key is on or off - if the trailer drains the battery with the AUX battery the van will still start.
• The relay for the Aux battery is mounted under the main battery - pn# F8UB-14088-AA
• His stock relay failed and replaced it with a PAC 200A unit and it has worked reliably since (about a year).​

My main battery reads 12.3V with the engine off and14.2V with engine running. If memory serves me, the alternator is also running at 14.2V

Currently I have my ARB CKMTA12 air compressor and a DC socket wired directly to the posts of the auxiliary battery - both have appropriate fuses in line. The compressor switch though is wired under the dash so that I can only turn it on when the key is in the ON position. I never have a trailer hooked up out back. When I originally set it up, I was only ever able to read 12.3V at the posts of the auxiliary batter whether the key was ON or OFF. This made me wonder if maybe my relay was not functioning but decided to just go for it and didn't have the time/patience at the time to continue investigating. The relay is tucked under my main battery and I was unsure of whether or not I was doing a proper test on it to see if it was functioning - I was also unsure of whether I had connected alligator clips to it properly to run to my multi-meter.

For a couple months (last fall) everything seemed OK - I used the compressor to air up 4 tires on a couple of trail days…then I went camping one night and ran a stand-alone Fantastic Fan inside the van all night - plugged in to the DC socket directly wired to the auxiliary battery. The next morning I started up the van after breakfast and we headed back down the trail. When we got back to the road to air up, the compressor wouldn't work hard enough. I decided to keep driving down the mountain and a few miles later stopped to try again and it was running again at full power. This leads me to believe that the alternator is charging the auxiliary battery.

Sometime in February of this year I tried flipping the switch for the compressor and noticed it wouldn't turn on at all - not even a slow chug-a-lug. Then went camping again in early March and threw the volt meter on the DC socket (the one directly wired to the aux. bat.) and saw there was only 9v coming from it - enough to charge a cell phone. Van starts up great but I haven't done a formal battery test. My auxiliary batter must not be able to accept the current coming from the alternator, correct?

So, I've got some sleuthing to do.

Here are my Future Goals:
• Figure this stuff out and do it myself. I've wired up a small house before when I was in my early 20's but I just made decisions about what was available - I went to the supply store and said, what do I need and they gave me stuff I worked with…with this project there are so many products to choose from, I'm kind of getting analysis paralysis.
• Run an ARB 63qrt fridge for 24/7 for multiple months of the year regardless of how long the van is parked.
⁃ We live in the front range Colorado so it will get hot inside but there will be plenty of sun as it is parked outside.​
• Run a MaxxAir vent fan on the roof 24/7 depending on our environment and sometimes the second stand-alone fan.
• Get either an Espar B1 or Propex heater for winter use at ski resorts.
• Have a small inverter to charge camera batteries, laptop, shaver, etc.
• Possibly get a small toaster oven - AC or DC I don't know yet.
• Hard wire everything to a fuse panel.
• Run 100-200W of solar on the roof.
• Get a Warn 1200 Winch
• Get a quality isolator - Blue Sea - need to decide which.
• Make an easily accessible and visible box that will make it easy to add components, change fuses, and monitor all of the accessories.​

Questions:
• Solar - Do I need 100W or 200W?
• Do I need 1 or 2 house batteries?
• Would you just replace my current factory aux. battery and call it the “house” battery or would you leave the factory stuff alone and wire in a newer set up?
• Which battery would you wire the winch and compressor to?
• Where would you put the new isolator?
• What tips and resources do you guys have for someone who wants to learn this - any certain YouTube Channel?​
 

jonyjoe101

Adventurer
if you are only reading 12.3 volts on your batteries, they are getting worned. After charging all day from driving etc, they should read 12.7 at least.
My 102 ah kinetik agm house battery reads 12.9 after charging all day. Its a 3 year old battery but still reads what it read when brand new.
For lead acid battery 12.3 volts is 70 percent and 12.1 is 50 percent, the lowest you want to go, everytime you go below that you reduce its life. At 9 volts the battery suffer some damage, you can do it a couple of times but them it will stop taking a full charge.

Some isolators only charge the aux battery once the main battery is fully charged. when the engine is running, the voltage to your aux battery should be climbing. When it reaches 14.2 volts its fully charge. If it always reads 12.3 its not charging.

If you got the room, put a 200 watt panel on your roof. I have a 240 watt panel on the roof of my small astrovan. I get a max of 13 amps of power when the sun is overhead. I dont even have my house battery connected to alternator its all solar. With big enough panel you might not even need to hook up to you alternator.
Your winch and compressor will probably have to run with your alternator running, I google the compressor and it uses 56 amps.

One of those 12 volt fridges uses about 25 amps of power in a 24 hour period when set to 40 degrees (i measured it), so 200 watts of solar should let you run 24/7 like you want to without turning your engine.

Instead of a toaster oven, get a roadpro 12 volt lunch bucket cooker, it uses 11 amps max and heats most food in less than 30 minutes. Just replace the 12 volt plug with connectors that can handle the amps. Its all i use to heat up food.

Also think about using a swamp cooler to keep cool, i tried the roof vent and the fantastic fan thing, but was never happy with the results. below is a picture of my 2 amp swamp cooler i built, its all i use now.

celdek small.jpg
 

Bbasso

Expedition goofball
My setup is close to yours, what I have is two 100 watt panels, two 155ah agms, blueseas ACR7622, PWM Controller, and my Engel 45 (@34deg) hasn't been off since I plugged it in back in October.
I use a propane oven and alcohol stoves. I too have a fantastic fan that I use frequently.
I'very been in rain for a week and almost never (maybe once hit 12.7) as a low voltage.
All my lighting us LED, I charge all sorts of items, from my bug zapper to the laptop. Plus I have a 150 wt inverter for any 110 charging needs and my 26inch Vizio lol

I've kept it simple and has been great.
 

FarmerFrederico

Adventurer
I'm going to drink the HandyBob koolaid and go with the Bogart controller, meter, temp. sensor.

I assume any of the 12V Renogy panels will work with this set up...I'd upgrade the wiring as he recommends. I think the single 150W (8amps) panel might fit best on my roof and avoid any shadowing. With Bob's formula of needing "nearly 3% of your total battery storage amp hour capacity in charging amps in order to successfully charge those batteries" that means I can have about 250amp hours of storage with 125 amp hours usable...but maybe I'd want an even smaller battery to make sure it is getting fully charged by the solar. Crown makes a 215amp hour battery.

The winch and compressor should be wired to the starter battery as far as I can see...because they should only be used when the engine is running.

The fridge, two fans, Espar B1, and lights as far as I've calculated their hours of daily use add up to about 65 amp hours. So, is a 215amp hour battery enough for me? I don't have an inverter in the mix - the only thing I think I'd need that for is to charge camera batteries or maybe run an electric blanket.

Thanks for chiming in so far!
 
Last edited:

FarmerFrederico

Adventurer
So I have in hand the Bogart Charge Controller, Meter, and Shunt. About to order up my panels now. Pretty sure I'll either go with two 100W Renogy Eclipse panels or their single 150W panel. If I go with two panels, I'll have to wire them in parallel - can anyone help me make sure I've checked everything off the list?

I've got a way to mount them to the roof - most likely using VHB tape and aluminum angle bar.

Using this to seal up hole for wire through roof: Blue Sea Cable Clam

Want to run #8 wire if possible, #10 at minimum and I know the panels are originally wired with #12. Anyone have input on rewiring that and then wiring them in parallel with that custom wire?

Do I need a junction box up top if I'm not planning on adding additional panels to the roof? If so, what should I use?

Thanks!
 

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