POPUP POWER FOR A DUMMY

[dreadlocks]

yeah thats why I originally switched to a fridge, went on a week long backpacking trip and start dreaming about ice cold beer and a big fat hamburger with everything on it.. then get back to the vehicle to find the beer warm and the food spoiled, damn 7 day coolers my ********.. thats why I needed fixed rooftop panels, now I can leave the rig parked at a ranger station for extended times and when I get back I can spend a few days recovering w/comforts and not having to run off for groceries right away.

 

[CampStewart]

What is the total cost A to Z of all of these solar systems you guys are recommending?

 

[shade]

What is the total cost A to Z of all of these solar systems you guys are recommending?

That would depend on the power requirements, and especially on the battery type & capacity.

A simple system:

$180 = 2 x GC2 batteries: https://www.samsclub.com/p/duracell-golf-car-battery-group-size-gc2/prod3590228

$205 = 1 x 315W solar panel: https://www.solar-electric.com/rec-solar-rec315np-monocrystalline-panel.html

$226 = 1 solar charge controller: https://baymarinesupply.com/solar-w...smartsolar-mppt-100-30-charge-controller.html

$611, and add in wiring, mounts, etc. With good sun exposure, that system would probably be enough to power an efficient fridge indefinitely. For under $1000 total, a good DC-DC charger could be added to allow charging off of the vehicle's alternator. I think that's worth doing so there's always a way to keep some power in the system, no matter the weather or other issues.

An additional benefit of using solar charging with lead batteries is the ability to reach 100% SoC without requiring long engine/generator run times, or several hours connected to mains power. Use good charge controllers, and they can be programmed to give the battery what it wants for long life.

 

[Justin Cook]

Hmmm that MPPT is no good for that panel... the SmartSolar 75/10 is only good to ~145w: https://www.victronenergy.com/uploa...-10-75-15-100-15-100-20-EN-NL-FR-DE-ES-SE.pdf

Plus, considering that a 315w panel could be putting (under ideal conditions) up to ~23A of charge current to those batteries, you'd be wasting half or more of your potential harvest. For a 315w panel going into a 12v nominal system, you want at least a minimum 100/20 (see the specs in the same manual above) to make sure that you're not massively clipping your harvest.
A SmartSolar MPPT 100/20 runs $157.25, btw.

 

[john61ct]

Overpaneling by 20% or so is usually fine, but yes even 75/15 is too small for a 300+W panel.

 

[dreadlocks]

1C = Battery Capacity in AH@20H.. IMO Deep Cycle FLA bank should probably be backed by a 0.15C charger max, 0.1C Optimally, I think .05C is a bare minimum or recharging from a deep discharge takes unreasonably long (days).. so for 215AH of GC2 the numbers come out to: 30A Max, 20A Optimally, 10A minimum for charge sources... you can hook more than max up to it, its just not gonna charge it much faster.. optimal is usually where it lands in cost v results.. Like you'd be better with an over paneled 20A than an under paneled 30A for about the same cost.

 

[shade]

Corrected - that's what I get for waking up in the middle of the night. Thanks, guys.

 

[john61ct]

Since batteries are a regularly replaced consumable, my preference for more permanent infrastructure components is choosing gear that will work well with whatever chemistries I might want to use in future.

I concede that may mean investing more up front, "buy once cry once" is not going to suit everyone.

If you want to keep things inexpensive yes guidelines are

0.15 - .2C for FLA

0.2 - .6C for AGM

0.4-.5C for LFP, unless faster charging at the expense of longevity is desired, personally would not go past 1.5C

 

[shade]

I concede that may mean investing more up front, "buy once cry once" is not going to suit everyone.

That's another reason I specified the above gear. If someone wanted to change battery technology, something more may need to be added, but nothing would require replacement.

 

[rayra]

Relatively easy to run some heavier gauge wire to the rear bumper, routed in some flex conduit for protection, to a bumper connector which you jack the trailer battery into, letting your vehicle charging system power and charge the trailer enroute. THen a panel and simple controller to feed the trailer when parked. And to keep it topped off in your driveway, for that matter.

I ran a pair of 1/0 cables to my Sub's rear cargo area, with a long range plan of having a carrier-mounted winch that I could run from either end of the vehicle (I'm finally getting around to that part now). They run alongside the frame rail, tucked within PVC flex armor conduit and up thru the cargo floor using circuit breaker panel bulkhead fittings. Whole run is basically waterproofed and protected. I'm about to add Anderson SB175 couplers / cable extension to both the front and rear bumpers (diagramming it now). A similar setup with lighter gauge wiring and conduit could easily connect, charge or power a trailer setup. With a keyed-circuit solenoid in the loop the trailer would be connected and charged while the vehicle is running and disconnected when it isn't. So you could run the trailer down as much as you want without impacting the starting ability of the vehicle.

My build topic link in my sig will lead you to most of the info.

 

[john61ct]

Yes that's a great approach, not nearly as daunting as many seem to think.

Even with 2/0 wire though at high amps voltage may drop too much over the distance, see BSS' Circuit Wizard app to check.

In which case a DCDC charger may be required at the trailer bank, but the ability to go with thinner gauge wire - just for thermal safety never mind the resistance losses / V drop - may well pay for a lot of it

and a maybe expensive target bank gets longer lifespan.

With LFP that approach is pretty much required.

 

[kennedyma]

After spending hours or maybe even days researching battery options for my 2005 Jayco Baja Popup.

I’ve settled on two GC2’s and a quality inverter/Charger. Something like the Progressive Dynamics PD9260CV.
There is a long list of reasons I’m going this route but the idea was to keep it simple as possible.

 

[slepe67]

you cant run a genset 24/7, you still need a bank to keep your food cold overnight.. and if you venture into any actual campgrounds your gonna a hell of a time getting it 100ft away without putting it in middle of someone elses camp.
...
OP has a little popup and almost zero electrical needs, really only wants a fridge and is considering powerless heat.. ye'all are going nutz with alternator charging upgrades, gensets and lithium and all sorts of expensive nonsense.

The more I research, the quicker this is becoming my thought process!

Like I said,
100-200W of solar panels
2x GC2 batteries
a small fuse block
a few 12v outlets
a volt meter

This can be made easy to transfer, just mount it all on a single piece of plywood, and you can just port it to a new rig. Might add a 5A trickle charger to keep it topped up if you park it in the shade.

After thinking and reading, your info makes perfect sense, but do I really NEED all of that? Again I'm not going to be spending a LOT of time in said camper, mostly sleeping and charging. I think it's great to have, just in case...but I'm also leery of having spent a small fortune on things and then not using them (guilty as charged on other things in my life!) LOL

Yeah, I know what I sound like now...I want this, but I don't...LOL It's giving me an ********** headache!

OP's completely gutted and rebuilt a 1970's Coleman popup from ground up.. he's in the unique position he can easily make way for a couple GC2's.. so yeah, he could put all his electrical on a slide out platform thats basically standalone, I dont think he even needs trailer power for breaks so he could make it as modular or integrated as he wants..

I would suggest wiring up a normal 7pin trailer harness to the popup, even though your tow vehicle wont really charge a bank that size via that plug it will let you drive across continents w/out your fridge draining the house bank much along the way..

Only thing I'd change about @luthj's suggestion is a bit bigger onboard charger, a 20A multistage w/trickle would be better IMO, would let you take advantage of opportunity power sources along your journeys.. like if you stop over for an evening with family/friends or just need to crash at a Koa after a long day on the road when your trying to cover alot of miles in little time and dont need hotels anymore... a 5A AC charger on a ~240AH bank is like trying to fill your bathtub by pissing in it.

Dreadlocks, so you're saying use the trickle charger as "shore power" to keep things tidy.

I have a 7-pin setup ready to go for the FJ, was told it wouldn't do much for my charging needs...but I guess it would work (like you said) to charge (more like" power things) while driving to the site and then use solar to keep the batteries topped up.

The shopping list (any proven/specific recommendations):
200W solar panels
2x GC2 batteries
20A multistage w/trickle
Blue Sea fuse block
a few 12v outlets
a volt meter

Anything else a guy could need?


I really appreciate the discussion. By talking to you guys about this, I'm learning what TO and what NOT to do.

 

[luthj]

You will be hard pressed to buy a portable power solution that costs less than the setup I described and can still run a fridge for a few days at least. The cheapest option is to buy a used battery from a junkyard for 25$. Charge it up at home, and toss it in the trailer. You will still need at least 1 fused outlet for the fridge, and some minor wiring for lights. Run the battery dead, could be 2-3 days depending on the fridge and lights. With no volt meter you would be kinda guessing about its state of charge. If it runs dead, you have warm food. No big deal.

If you want really cheap, get a couple battery powered stick-on lights, and a ice filled cooler. A good cooler will keep for 3-5 days in modest temps.

 

[dreadlocks]

Whats your camping style? are you just a weekender? If so you dont need solar, just plug it back in when you get home.. like I said earlier, if you get a somewhat decent fridge a pair of GC2's should comfortably run it ~6 days, 4 days in absolutely terrible conditions (like desert camping and restocking alot of beer).. which would cover most holidays and outings.

Solar becomes a requirement for extended time out, to go on a two week vacation for example would want 6-8x GC2 batteries and that puts most people way over their weight.. a couple solar panels dont weigh nothing in comparison.. and appropriately sized could let you travel indefinitely.. alot of people move from coolers to fridges if they do extended adventures because finding and buying ice ends up consuming alot of time and money.. Ive had to take 2.5h drives to refill our coolers before, that gets old fast when you can carry enough food/water to stay put for weeks.