The 50mm Ammo Box Solar Generator project.

[calicamper]

Photos to be added soon.
I have the basic parts and have been fooling around with them since Saturday.
The heart of the system is a $27 solar controller for battery/solar street lights. It is a fully set up battery manager with voltage screen and various modes etc. It even has an out put up to 20Amps max which will shut off when the battery hits 11volts.

The use for this set up is very light power needs. So I have a 18ah 12volt battery thats a perfect fit in a 50mm ammo box. The solar controller/charger will be mounted in the box also as it has a temp management feature also. I bought a Renogy 10watt small solar panel. So far the quality of this stuff is impressive. Doing some load testing and solar panel testing I think this set up will handle our light power needs.
The little atv KAWELL LED flood draws 1amp. This will be mounted to the back of our trailer with a remote led key fob switch.
I have basic plans to add some small led strip lighting inside the tent draw will be pretty low 2 amps at the most. The big power draw will be a charging hub for gopro, cellphone etc.
Tonight Im going to test the 11volt shut off, then have it set up for solar charge the minute the sun comes up.
The little 10watt panel easily generates 15volts in full sun and can manage over 14volts in shaded location which is pretty damn good. So we'll see how it goes. If I need to add more solar capacity Ill get a second panel as these are small and can easily be packed up safe for rough roads etc.

 

[ober27]

This sounds interesting, keep us post on how it works out. Photos are always nice as well.

 

[AlanLoshbaugh]

could this be used to power an arb fridge?

 

[calicamper]

Just taken this morning



As for ARB question it works like a bank, if take $500 out and only put $50 back in it doesn't work. What does a ARB draw in AZ when wheeling? My little battery is an 18ah battery. So the little Atv flood light that draws 1amp in theory will run 18hrs. Though you generally knock that down to about 75% of that for ****s and giggles.

My use is just very very basic couple of LED lights, and a charging hub for small items, phone, ipad, gopro etc. The battery banks the solar power during the day then powers my lights and charging stuff at night etc.

For Solar power you dont really want to over do your power generating give its just wasted $$ spent on too much panel capacity. So at the moment I'm trying to get away with the smallest high efficiency panel on a budget $36. I can add a second one if needed. But so far I think this will cover our needs.

The ammo box will be mounted to the front plate of the trailer next to the tongue box. Ill add a lock to it and it will stay on the trailer.

 

[AlanLoshbaugh]

Looks like:
Average Power Usage: Average 1.9 Ah/h (@12 V, -15°C interior, 32°C ambient temperature)

 

[dwh]

Looks like:
Average Power Usage: Average 1.9 Ah/h (@12 V, -15°C interior, 32°C ambient temperature)

2 amps per hour, 18 amp hour battery - around 9 hours till battery dead.

Replenish - 10w solar is less than 1 amp, so you'll need more than 18 hours of good sun to recharge the battery so you can run the fridge for another 9 hours.

 

[calicamper]

Looks like:
Average Power Usage: Average 1.9 Ah/h (@12 V, -15°C interior, 32°C ambient temperature)

Which case for the ARB I would go bigger battery and my little 10watt solar panel in tottally perfect conditions looks to be maxed out at 18volts and just over a solid amp charge. Which case larger battery for sure figure 2amp per hour loss at night, then you need solar capacity for both charging an empty battery but also powering the ARB. So you need solar capacity in the range of 3-4 amps guessing your looking at 80watt good quality panel at minimum, to both carry the ARB load and drop enough power to the charge controller to charge the battery up.

So lets say bare minimum world is perfect for solar charging 15hrs of no charging dusk/night time your ARB burns 30ah of battery juice. Lets say you you have a 60ah battery in a box some place. Your ARB burns 30ah of power off and your margarita blender that night burned another 12ah off the battery light weight cheap dates we all are.. your battery is flatt ARB is getting warm by 8am, and your 80watt panel is now pumping out power. So you have 10hrs of solid 100% solar generation and your charger is able to dump 1.5 amps per hour back in the bank. You need 42ah put back. 1.5x10=15ah. You wont be blending Margaritas that night and your ARB isnt keeping the Haagen Dazs cold for your midnight snack either. Youll need more power generation frome some place.

 

[AlanLoshbaugh]

I think I understand: I'm not super savvy about this.
Maybe what I might need, for me and the fridge thing; is a solar trickle charger.
Fridge users seem to report being able to leave the truck off for 2-3 days and not killing the batt to where you're stranded, but can re-start and charge by running the truck.

 

[calicamper]

Its cool stuff. Fun to mess with. Hell free power is cool..
A typical nothing high capacity car battery is around 40+ish ah rating. If some one is running a deep cycle battery they'll get more amp hours. It looks like an ARB in my Subaru would have the car dead in about 20hrs. A deep cycle marine battery might have 120ah capacity though.

 

[AlanLoshbaugh]

The fridges don't run full time though; if that's what you're basing your numbers on....fwiw...

 

[ober27]

I wonder, since your carrying it near the trailer hitch, would it be possible to charge it off vehicle while driving? What would that require, a 7 pin connector? What type of battery do you have?

 

[LandCruiserPhil]

I have basically the same set up with a smaller box and uses a 27W foldable panel
If Im on the move it can be plugged into 12V for charging for my needs at night.

http://forum.ih8mud.com/threads/new-mini-power-supply.609425/#post-7828142

Running a fridge is not an option even with a 27W panel but I do use it to power my heated bed for cold nights

 

[calicamper]

2pm in California 78 degrees full sun. 10watt renogy $36 solar panel.. This thing is amazing
19.9 volts!!!
Im impressed

 

[calicamper]

I wonder, since your carrying it near the trailer hitch, would it be possible to charge it off vehicle while driving? What would that require, a 7 pin connector? What type of battery do you have?

In my set up by design I'm not hooking it to the car power. Trying to keep it super simple. That and our usual vehicle choice is a 4pin attached to a Subaru. I'm not going to get crazy and wire the Subie for a 7 pin. Having said that the charge controller in theory could be looped into power off the car and then be used to manage battery status. Battery at 13.4 volts and the solar panel at 17volts it switched from bulk to float meaning its at a trickle charge status. Max charge protection is 14volts so when the battery hits 14 the charger will kick off. So I would guess power from the car would allow the charge controller to do its thing.

Tonight I'm going to run a few things on the battery and bring it down near the 11volt dead point then see how the charge performance goes tomorrow. Just set it out as if it were in camp and see what we get.

 

[crusaderJK]

Looks like:
Average Power Usage: Average 1.9 Ah/h (@12 V, -15°C interior, 32°C ambient temperature)

The fridges don't run full time though; if that's what you're basing your numbers on....fwiw...

Those "1.9Ah/h" already take into account, that the fridges don't run all the time.

I use an 80W panel and a 75Ah deep-cycle battery to power my fridge. The fridge can run off the battery for 4 days without any recharge from the solar panel.
The solar panel produces over 4A in sunlight, and 1A when partly clouded.