Off Grid Capability

How well does that actually work

 

I'm running a Dometic CFX35 on my house stock/OEM battery. I've sat for days at a time with no issues. I'm up at dawn and, even with overcast conditions, I am seeing a charge from the solar panels when I get out of the tent and check the voltage. So, I'd say it works well.

 

Nice. Thanks for the info.

 

That looks way more expensive that it should be. Could be built for way cheaper. Nice setup though.

 

I mostly help people with vans and related solar / electrical.

In a van, we would call 85 watts a starter battery trickle charger so that you don't end up like the "Breaking Bad" episode where the RV starter battery is dead in the middle of the desert.

Solar really starts to become interesting / useful at 300 + watts for refrigeration use.

 

I have about 20’ of 4awg running to the rear junction box. At the battery there is a 125amp MIDI fuse. The wire is in expansion loom and runs along the factory harness on the driver side of the truck. All terminal connectors are nickel clad copper marine grade. The 4ga terminates in the junction box at a BlueSea fuse box. Fridge and rear lights are powered from here. My compressor wiring T’s off of the fuse block and goes through a 70amp busmann circuit breaker before going to the unit. This is because the Puma compressor spikes to 60 amps at startup and then drops to about 35 amps.

I sourced the SB50 Andersen connectors and environmental boots online and made my own brackets out of aluminum angle.

I wanted a system that was expandable as I didn’t want to have to run larger power cables to the rear later as my needs increase.

hope that helps.

 

Cascadia 4x4

 

Thank you for the link to your build thread. Some very useful info there.

 

Quick tip for trying to size the right gauge wire for the load and distance, Blue Sea Systems has a free phone app called "Circuit Wizard". Super handy if you're not in front of your computer or a paper chart.

Like most marine-based specs, it takes into account fusing and a few other things most people don't add into their calculations for automotive work. It definitely errs conservatively on the side you'd want it to.

 

Ohhhh boy. Vague indeed.

Well I haven't read everyone's response, but...SOLAR and WATER

I would recommend 12v deep cycle marine batteries that charge off of the solar (You'll need a charging controller also) AND are isolated from your car battery, but can also be charged from the alternator. Throw in a 120v inverter for fun too.

Once you figure out what you are going to be powering (ie; fridge, lights, fans), do some math and see what size battery (or batteries) you need. [Watts=volts*amps] - always a handy formula. Also factor in some headroom on your batteries incase you camp in a tunnel, overcast, storms, etc.

As far as water goes, we can talk a bunch about this. I have a water system that allows me to pump IN to my tank and OUT, so I can rock up next to a river and grab some fresh water. Twice filtered before use too. Happy to talk at length about this if you would like.

Go on a few trips, see how you live and what you like/need

 

If you are serious about wanting to use it as a "conditions are so bad we are leaving home" vehicle, it might make sense to consider packing some of this stuff in a trailer.

Counting on the electrical capability of:
- A single size 25 aux battery
- The small capacity of the tacoma alternator
- The solar panels that can fit on a Tacoma
- An inverter that can be actually powered with a single size 25 battery

Will be marginal very fast.

Switching to LiFe batteries will reduce weight, but won't actually power anything that you can't with a good quality AGM.

As an example, I am helping my neighbor with adding some aux power to his Tacoma and we are searching for locations to put in 4 each, size 24s to run a 2 kW inverter.

Still looking at options, but it is tight everywhere.

 

Yes, sketch out your requirements ahead of time.

Use a common measure throughout (Amp Hours per day).

For myself:
Fridge: 24 Amp Hours per day
CPAP: 8 Amps Hours per day (humidifier takes power)
LED Lights 2 Amp-hours per day (really dark days)

Flooded and AGM Batteries will be rated something like "70 Amp Hours" so you think "aha, I need 35 Amp Hours per Day" so that is two days. Well, you only get maybe 300 cycles fully depleting them. So Aim for 40% usage so 70 Amp Hour that is 28 Amp Hours per day. Hence adding a solar panel to supplement the usage makes more sense.

Lithium-Ion batteries can be used for 90% of their range, so a 100 Amp Hour battery would be good for 90 Amp Hours, three days. They are best between 32F and 120F. Don't put them under the hood. Flooded Lead Acid does best under the hood (high temps). AGM's fall between them (high heat kills their life, but since they recycle the vapor no adding water but you will need to have a vent go outside as they can vent hydrogen in extreme cases. Explosive gas). Battle born does an interesting "heated battery" so If I am cold weather camping, but have solar on a crystal clear day use the solar power to warm the battery above 32F so it can accept a charge. Yes, you use battery power to keep the battery warm. If temp shuts down below 25F you can not draw a charge from it, but I usually don't do polar bear camping.

In the past, I had dual 70 Amp Hour batteries, one for starting one for the house. Ganged together, relay opened if voltage dropped below 11V to reserve a starting battery. 100 Amp solar panel moved around during the day kept charge up for four days off-grid. My T250 Ford had a 250Amp Alternator, so easily charged 100 Amps back into the batteries (often I would park, camp, hike, and bike ride, moving every four days about 200 miles down the road).

@harryn any luck on battery location? I was under my Long Bed, and not a lot of room. A decked storage system gives room in the bed aft of the cab. On electric vehicles, under the bed was ideal but I didn't have fuel tanks nor exhaust systems to deal with. I had much more room under the T250 Cargo Van for battery boxes and water tanks,
but with the Tacoma, there is just a lack of room. The irony between rear sheet metal and the bed is a surprising amount of room I could almost get a couple of 8D in there with a little sheet metal work.

Just food for thought on how we got batteries under the van (it was a Unibody, but had a ton of room under there. I like weight down low between tires for handing).

 

Yes, I agree.

I tend to use watt-hrs as my consistent measurement because then I don't have to think about if it is 120 vac or various DC voltages, but amp-hrs of consumption is more common.

My neighbor has been out of town so I have not been able to look at the truck more closely.

Thanks for the suggestion to look around the bed / sheet metal interface area.

 

A little thought also about getting an 120V inverter. The majority of them output a modified sinus wave and not all devices work with them. A simple motor driven device like a drill shouldn't have an issue with it, but devices with some more electronics in them might quite.
I tried to charge my Laptop with a inverter and it just looked like the inverter was dead, but at the end I figured that the laptop charger didn't like modified sinus wave of the inverter.

 

Makes perfect sense. I have a number of customers for van electrical systems with the Ford Transits. A lot more options for dealing with batteries. 4 x 100 amp-hr batteries + 2 kW inverters is routine.

Have a sprinter project going with 8 x LiFe and 4 kW of inverter capacity.

It is always a learning experience with each new vehicle type.

 

Hein and Kim are always coming up with neat solutions for Sprinters and Transit's. I'm just a happy customer.
https://diyvan.com/collections/transit

I went crazy trying to find another source for the 600 Thinsulate, but never could. They buy in bulk, but handy stuff for quitting the interior.

If our Tacoma's didn't have composite beds it would be more tempting to cut a hole in the bed, clearing the frame to recess house batteries. You can do that to the composite bed, but if you go to resell it the next person might not appreciate the modification. Then again how many people look under a bed rug?

 

I'm not joining in on the prepper discussion... but I've first hand witnessed a friend that pumped 40 gallons out of an old motor yacht that sat dry docket for a decade (outside with humid summers.) Dude pumped it straight into his late 80s era GM powered class A motorhome without filtering and successfully drove to Canada. True story.

 

That would be really difficult to do now with modern retail oxygenated fuels and fuel injection.

 

awesome idea, bad part is solar panels and batteries have a life span. But definitely far superior to gas powered vehicles. Having solar panels and generator to go with them has been a game changer, nonetheless.

 

overpriced and it 85 watts on a slim laminated panel isnt going to last, in fact they all delam, even ones that go on other places. I too had these questions OP. @Guami54 this is what I did. I bought a bluesea system panel and cut into my bed of my truck in the rear next to the cubby hole. I first ran a 4G wire from my battery (northgate 31a) to the rear bed, i removed the cubby door and ran the wires into there and sealed the holes with buytl tape ( has held in mud, water, snow, and extreme heat in NV conditions) I added a bluesea fuse block and made a simple , I also did the same for the backseat , minus the fuse block, just a prewire. I also made this a prewired a universal fridge plug for (arb,dometic)on some quick disconnects.
All and all I have roughly 180$ in parts, including the solar panel and the battery controller. Renogy makes a 100watt kit in which got me a max of 88 peak watts in direct sunlight facing south optimal conditions) mounting that 85watt panel on the hood although is cool, IMO isnt great. You will loose efficiency, its a pain in the butt to remove and reapply. panels can be mounted anywhere roof racks, RTTs and many more, they will last longer for SHTF, cheaper and you learn some valuable knowledge after install. If you have any questions just PM , Im all about solar, and testing the true off grid capabilities of the Tacoma.





I have ran my dometic 6 days straight , my 360 camp lights , and much more on camping trips, they hold their own well. You can get the same renogy kit as I here https://www.renogy.com/renogy-100w-12v/starter-kit/ they have gone up in price significantly. since last year.

one more thing I forgot to mention, I have ran my Cpap machine via the outlet as well...