This was amazing information!!! Really, I sincerely appreciate you taking the time to write out such a knowledgeable and thorough analysis to this topic. It is a lot of information to digest, especially me being new to all this, but your info has helped a ton.
It didn't take as long as it looks, but you're welcome. I aim to educate before someone just goes out and spends too much on something they'll regret.
To sum things up, here are some takeaways I took from your experience:
1) I totally get the benefit of having the dual battery setup to "jump" your starting battery should it die. However, I was thinking of purchasing a small portable jumper kit from Amazon that I would always keep with me anyway for myself or someone else on the side of the road.
Exactly what I do, I use the best I could find for a good price, the
Antigravity XP-10
2) The stock alternator isn't designed to handle topping off 2 good quality batteries. That makes sense. My runner is sitting at 180k miles so I'm sure that would only speed up any failures.
3) Since the stock alternator can't top off both batteries efficiently, if you ran your fridge, it probably wouldn't last one day. And if that wasn't detrimental enough, imagine if you were running something else besides your fridge. It would only make matters worse.
4) To help alleviate your situation, you have solar panels in addition to your alternator that charge your auxiliary battery and that has been working great for you. (Do the panels wire directly from roof into auxiliary battery?)
I only have one battery, but I upgraded from stock to a Group 31 by Odyssey. For the solar, have the
Renogy Solar Suitcase, it sets up on the ground, the charge controller is under my hood, and I made a 25ft cable that allows me to set up the panels nearby.
5) Despite running your Engel for days just fine while your runner is parked, do you think maybe you'd run into some risk if you were powering other devices like I mentioned?
Most of the items you describe can be curbed by discipline. In other words, stuff I'd only use when my battery is topped off, or plenty of solar charging time left. The biggest worry actually is the fan. An inefficient DC motor spinning all night will drain the battery pretty quickly. Blenders can be found in 12 volt so that you won't need an inverter. The best blender I ever made worked with my Makita drill! I made it so we could have margaritas on our boat without having to add complex electrical items like an inverter.
6) Now onto the portable battery setup, a nice benefit is being able to have different methods to charge the battery. Can they receive charge from the vehicle's alternator in addition to receiving charge from solar panels at the same time?
I know the Goal Zero units have a 12 volt cigarette adapter to charge it from the vehicle, There are a few others, Arkpak for one, that do as well. These outlets aren't going to use a massive draw, and won't charge quickly, but it will help to keep a unit topped off while driving and keeping that fridge going.
7) And now that I asked that last question, I realized maybe that wouldn't be smart since we just concluded the stock alternator isn't designed to charge "more" stuff.
8) But let's say I was charging portable battery from multiple sources, maybe solar and 12v cigarette lighter, do these portable batteries automatically stop accepting charge once they reach 100%?
Yes, the good ones, ArkPak and Goal Zero - some others, have built in charge controllers to keep the battery from getting damaged.
9) I forgot to mention I want to install some lighting such as bars, etc. If I went the portable battery route, would the lighting just be fed off stock single battery?
Light bars, driving lights, etc; these would run only when the vehicle is running, and should be kept to your stock vehicle battery. Do it right, get a fuse block and run all your power leads to that, so that your battery terminals don't become overloaded with wires from all over the place. The only thing getting its power from the battery is the fuse block. If the fuse block is close enough to the battery (within 10 inches or so) you don't even need a breaker/fuse. But many, including myself use a breaker so that I can kill the power to the fuse block if I need to.
10) Last question, if I did the dual battery setup, how do I power things inside the vehicle? Is it mainly done through installing USB ports, cigarette lighters, and 120v sockets inside vehicle that are fed off auxiliary battery under the hood?
Click my build thread link, review the second page, I chronicled the re-wiring of my 4Runner.
I know there's a lot of questions here, but any more input you can give would be much appreciated. I really do enjoy learning about this stuff and it will help me decide which route I take. Looking at the cost of an Inergy Apex or a GoalZero 1400, it seems buying a portable battery might cost the same as a proper dual battery setup so just trying to see what would be easiest, more efficient.
Lastly, on a tangent, but I wanted to ask why do you have an Engel? Are they better than others? I have been looking at the Dometic CFX 50 quart and the NEW ARB Series II 50 quart because they are the ones available to me locally. As a matter of fact, I was thinking of putting in the order today for the new ARB with its protective bag but wanted to ask you first, since you have an Engel. Am I missing something or are these fridges pretty much the same and any would be fine?
Yup, a dual battery installed by a pro, including all the wire, the parts, the batteries, etc, could run as much as $2500.00 installed. I've never seen that Inergy Apex before, that looks pretty robust, and probably more than you'd ever need in the wild, but it has all the features I'd look for in such a solution. Not cheap by a long shot, but if you feel it will meet your needs, buy once - cry once! Like you said, much cheaper than some alternatives.
As for my fridge, I bought my engel because it's the most efficient fridge out there. It has only one single moving part, a key design feature of the Sawafuji. There are no other failure points to the system.
You can read about the Sawafuji Swing Motor here. I also got a good deal on mine when engel was running a sale. I've personally seen engels out in use that are 20 years old. I don't expect my house fridge to last that long.
Dometic makes a nice fridge, I'm a bit jealous of the bluetooth apps to control these modern fridges, but to compensate, I picked up one of these
SensorPush bluetooth thermometers, and it works AWESOME, including alarms that I can set a too low temp and too high temp that have my phone send me a notification when something is wrong. They're not cheap, but they're extremely accurate out of the box, the app supports multiple sending units that can be named in the app for the device it's in. And I don't have to reconnect it whenever I walk back near the truck. At any moment, I can open the app, and the date/time stamp on the last reading is usually moments before I opened the app, so it does it all on its own.
Hope this helps.
