I understand what you are saying… I just went on my own tangent.

I have experienced the same thing before in my Silverado. Internally some of the cells failed, permanently lowering the operating voltage of the battery rendering it useless.

Spent two weeks in Baja Mexico with hundreds of off road miles and the new Redarc + solar system worked flawlessly. Ill update my original dual battery setup thread when I have time as I think this is a much better setup than using a basic solenoid. Although, one could probably get away with a solenoid + solar supplemental power.

Did you end up getting a new AGM, or are you trying to nurse your old one back to health?

Still using the original. The resting voltage is around 12.6V now which is totally normal. Seems to be ok at just about two years of use even after I drained it flat a couple of times and charged it with our weak alternator.

That sounds much better.

If you had a hard time holding voltage then your internals are sulfated, but it can be repaired if it’s not too far gone. Sounds like you still have some service life in it.

I would keep bringing it up to its full charge voltage as often as you can.

Thanks for the recommend. I am planning on installing this system. What size AUx battery are you running? I am planning group 34 AGM. Also, what size and type of solar panels are you using? I am considering a flat panel on top of a rooftop tent. Mainly to charge at trailheads while we are away hiking and climbing. I will supplement with a flexible deployable mat when static at camp. Just don't fancy leaving a 1000 dollar solar blanket draped on the 4runner while away climbing for hours. What size wire did you use on the Redarc? Manual for the 1225D suggest 6AWG. I am going to add the Redarc smart solenoid down the line for jump starting and winching with both batteries linked.

@SnoRnR Im running a Group 34 55ah Odyssey battery mounted in the secondary OEM location and honestly wouldn't really go bigger/heavier. Our engine bay is made of soda can thin sheetmetal and stress fracturing is a real thing. Reused most of my wiring from my original setup 0/1AWG so a little overkill but it works fine.

For solar im running two 120 watt Richsolar which is total overkill IMO. I dont really think you need a solar blanket with a setup like this. It produces a lot of power even in the shade which was surprising.

I honestly think the use case of linking of batteries for jump starting and winching is a bit overblown. Unless you are constantly winching for extended periods your standard battery should be fine. As far as jump starting I have a set of jumper cables that I could use between the batteries or even more convenient my LI-ION jump pack.




Sent from my iPhone using Tapatalk

Awesome answers all my questions. Is the cable down the windshield from the solar permanent mount or do you set it up when you stop? I also carry a li-ion jump pack.

The wiring is permanent as well as the solar panels. On a side note I used my winch extensively this weekend when driving through 2-3 ft of snow on backcountry shelf roads (At least 15 times). Never had a problem with my M8000 drawing from my cheap Duracell 55ah starter battery.

I'm running two Odyssey group 24 batteries on an Off Grid Engineering system. I added a fuse from Australia that bumps the alternator output so it charges the Odysseys between 14.2-14.5. The system works flawlessly and keeps the batteries charged consistently at 14.5. I almost went with the Genesis system, but the battery module simply gets too hot which is never a good thing regardless of what the manufacturer says. The Off Grid Blue Sea module runs cool and efficient, it's totally water proof and in auto mode requires nothing from me. I can self jump from either battery and run my fridge, lights, and teardrop trailer off either battery or both. When it charges it charges both until they are at max volts and automatically shuts the aux battery off and goes back to main battery charging. I love the system, been almost 3 years now with zero problems. Pricey but worth every penny.