The 12v accessory ports deliver 14.1v and according to documentation, 10A maximum - total, and so if there are other devices mooching off of the 12v 10A circuitry I am not surprised one of the ports may not have sufficient juice when needed. And when needed is when the cooler, for example, needs to start the cooling compressor to catchup with the user-set temperature. I have had a unit plugged in for about a week and have been testing it out, and when it does need to cool itself again it pulls between 4 to 5 amps - never really 5 amps, but it is rated for that. The cooler usually takes about 3 to 5 minutes to get to the desired temperature and then it goes silent again - pulling no current.

There is also the inverter circuitry that can be used as an alternative.

Looks like a good setup, thanks for sharing. I might consider something similar. But the more I look at my needs the more I realize I will be needing the cooler powered all night by the battery (Jackery, etc.), and then at dawn the battery needs to be getting solar charging. There is a lot of disconnect this and reconnect that going on in my mind and I want to limit that. I am trying to imagine the needs and build around it.

Looks like a good setup, thanks for sharing. I might consider something similar. But the more I look at my needs the more I realize I will be needing the cooler powered all night by the battery (Jackery, etc.), and then at dawn the battery needs to be getting solar charging. There is a lot of disconnect this and reconnect that going on in my mind and I want to limit that. I am trying to imagine the needs and build around it.

So, after some searching, YouTube watching, I have contacted a couple of local Overlander Outlets and prices are very high. One has given me at estimate of $6,000 (US) with 50% of it being just labor. Another one will be giving me an estimate this week and I am not holding my breath.

The toughest thing to get done right is properly passing of the heavy gage wires from the engine compartment to the other end of the vehicle. I have watched some videos and it isn't something that I can do without spending a lot of time learning, and it isn't something that I can trust just any shop to do.

Maybe if I could find a good shop I can just ask them to do the main cabling without connecting to anything at any end, then I can figure out the rest and maybe even take it back to them to do other parts of this in steps so that I can afford it.

Hey, just for laughs, I have a couple of schematics of the system that I think can work and I have attached them to this message. Well, hopefully not just for laughs, and at least also for discussion.

Attached Images

   

Well those aren't exactly schematic diagrams for electrical of electronics, but they convey the idea at a high level.

As I mentioned in my earlier post, I did a marine grade second battery install in my boat. I did it myself, and its non-trivial if you don't know much about these systems. One of the things you need to add is a way to cut power to the second battery manually, You also need fusing. I had a little background in electronics so that helped.

On my boat system, I also included the ability to switch the secondary battery in line to start the boat should the primary battery fail. This requires a fairly complex switch wired with large battery gauge wire. I think I used flexible welding lead wire which is a pain to work with. This may not be a requirement for a vehicle.

By use of an isolator, and a regulator the system charges both batteries, until the secondary is full. Then just the primary. So anytime the secondary drains to a certain threshold, the system automatically sends some power to it to keep it charged as long as the engine is running.

This is why I strongly urged the use of the Jackery. It may be lacking somewhat, but it is far simpler and easier than doing all the wiring that just sits in the vehicle until you take your next trip. BTW you also have to select the right components depending on the type of battery you will use as a secondary. Choosing an advanced chemistry battery requires the proper charging system. You cannot use the same charging system for all batteries.

All of the electronics are built into the Jackery. You just plug the Jackery into a 10A 12V circuit in your vehicle. It does everything else. Its the isolator, the regulator, and the battery. You just plug your refrigerator into the Jackery, it does everything else.

The one downside of the Jackery 1500 for your needs, is the slow 12v charging. There are ways around that because you can plug two charging sources into it at the same time. But I'll let you discover how to use that if you want.

The Jackery 1500 is also optimized for solar, so you might want to look into getting a couple portable folding panels if you go this route and you have sun.

I would think that a 1500 would power your fridge for 3 days without a charge anyway if the temp wasn't extremely hot and left in the sun. BTW try not to open the fridge often (kids do that). And pre-cool the food before loading the first time and you will get much longer battery life.

I would not recommend the Jackery for someone who lives out of their vehicle, or is overlanding without moving frequently. But for most of us who usually go out for one to four days, and don't use electricity for cooking. I think its a great option.

JMHO




This regulator keeps the secondary battery from being over charged.

I think this is what I used for my boat.

Add-A-Battery Kit - 120A - Blue Sea Systems

This system switches batteries too. Batteries need to be similar. Don't let the simple look of the box fool you.

You can buy simpler systems that don't do battery switching too. But the wiring and installation is not easy I promise.

Your advice is sensible and it is appreciated. A Jackery or similar is part of my plan, and my plan usually is made of Plans A, B and C.


Farzad

Oh, OK. Well good luck, I hope you find a system that works for you.