Dual Battery Setups! Let's see them! Multiple Batteries Thread!

It’s about 1/2” longer and taller than the 27dc from Advanced that it replaced.





It’s a tight squeeze, but it fits.

 

I'm getting ready to wrap up my dual install with a

$80 Renogy 20A 12V/24V Auto DC Input MPPT Solar Charge Controller Parameter Adjustable LCD Display Solar Panel Regulator fit for Gel Sealed Flooded and Lithium Battery, Rover 20A,black

Renogy 20A DC-DC charger and trying to determine where to run the D+ wire? My understanding is this should be run to a switched power that is only powered when the truck is running and NOT in ACC. When searching everything that comes up is about the INJ fuse, but thats powered when in ACC.

 

wow, that's a lot of read. only started at year 2021. but whew!
read because my dometic 75 wont charge w/ tacoma trd 2023, the more i read the more i found out that dual bat is not the way for me.
since i live in florida and we have hurricanes that knock power out for days so i think i'd go with a 2000- 3000 watt powerbank instead of a 2nd battery- this way when we have no power i can use teh powerbank to power the whole house.
main battery > inline fuse > victron (tapped to ignition fuse) > ecoflow/bluetti/anker > whatever device i want to power (dometic, electric heater, induction stove, coffee maker etc.)

it's simple and multi purpose.
these power banks have extra batteries that will push to 10,000+ watts very handy during hurricane season. currently looking at the ecoflow delta 2 max 2000 watts (extra battery 1000 watts per battery) or anker solix + extra battery

comments, pros/cons?

 

I own two EcoFlow Delta’s and two portable 160watt solar panels.

Pro’s
1. they run my Dometic Single Zone 35 quart Fridge/Freezer at 37 degrees for 2+ days in 100+ degree weather when running on the DC plug.

2. recharge rapidly when using ac.

3. Can get to preferred 80% charge with Solar Panels in about 8-10 hours of sun

Cons

1. Lifespan is less than Bluetti 800 charges to 80% rated at 60% after that. I’ve owned and used mine in multiple applications for 2 years no issues

2. fan noise is a little loud

I love mine. Would buy them again. Much more useful than a dual set up for me

 

Pulled the trigger on an onboard charger to keep the house battery topped off in gloomy western PA.





Ended up with a

$70 Noco Gen5x1 , 1-Bank, 5A (5A/Bank) Smart Marine Battery Charger, 12V Waterproof Onboard Boat Charger, Maintainer and Desulfator for AGM, Lithium (LiFePO4) and Deep-Cycle Batteries

Noco Gen5x1.

It’s connected to the start battery but all I have to do is flip the ML-acr switch and it’ll charge both.

I just need to find a better place for the plug that’s just tucked up ne t to the winch currently.

 

Anyone have experience/feedback with using one of these cheap self-heating lithium batteries?

$340 12V 100AH Group 24 Self-Heating LiFePO4 Lithium Battery with Touchable Smart Display & APP Monitoring, Built-in 100A BMS,1280W Load Power, 5000+ Cycles, Perfect for RV/Camper, Solar, and Off-Grid

https://www.amazon.com/Self-Heating-LiFePO4-Touchable-Monitoring-Off-Grid/dp/B0CPP8K14N?ie=UTF8&th=1

My current setup is a Renogy 30amp DC-DC, 200 watts of solar, and a Northstar AGM. It's been working flawlessly for 3 years. I currently need to buy a new starting battery, so thinking about swapping the Northstar for a lithium to upgrade and save some weight at the same time. I want to permanently mount it to the truck, where it will be below freezing all winter.

I don't really understand how the self-heating works, and want to make sure it won't just spend all winter keeping itself warm, and hardly ever charging.

 

I know absolutely nothing about Lithium batteries except that my next house battery will be one, even though that'll mean reworking a bunch of my setup (no more ML-ACR, need a DC-DC charger, probably a larger alternator, etc.). Unfortunately, that might be sooner rather than later, depending on how my batteries look when I head back down for my next trip.

Anyway, I, at some point, ran into this guy on YouTube. He reviews a lot of the budget (and not) LifePo4 batteries, and seems to be a straight shooter, a lot like Project Farm.

I did a search for "self heating lifepo4 battery" and came up with this video of his:

https://www.youtube.com/watch?v=EaiwxDUY9ho

I watched it and I don't think it totally answers your question, but it might be a good thing to put a temp sensor wherever you plan to put the battery, and see if you ever get below freezing there when you would want to be charging.

Another option - which is really just a manual battery-temperature-management - would be to add a killswitch to the charging circuit, so you can disable charging when the battery is below freezing. If the battery is in the cab, that might mean flipping the switch to off at night, and then waiting for the cab to heat the battery in the morning before flipping it back on. If the battery is in the GFC, it may be that with your body heat, it never actually drops below freezing.

Anyway, I say all that, but mostly I'm curious to see what you do, and learn from it!

 

I want it to be charged all the time and not have to think about it - is my hope at least. Good suggestions about disconnecting it, but I daily the 2nd gen, which means short trips that will trigger the DC-DC charger, solar every day, etc. etc.

Battery is in the bed and will likely hardly ever be above freezing most of the winter. I might be able to fit a 50ah in the cab, which is probably fine for what I need it for, but don't feel like reworking everything.

The renogy charger has a temp sensor, and the ability to add a battery probe, but sounds like the BMS of a battery would take care of all of that itself.

Temping to try it for $250 - especially being I need to spend that much for a good starting battery. I think worst case I could leave it in the truck, mostly charged, and disconnect everything most of the winter, being I'm don't need it much then anyways.

 

The self heating batteries will have a draw but it shouldn't be huge. What will you be running off your house battery? If it is something that is critical definitely get a self heated battery or insulate and heat a battery box...a small heating element with a thermostat set at minimum operating/charging temp means you can get a 100ah for ≈$120.

I'm running an unheated lithium in the bed of my truck but it's in a small compartment in the bed and the bed is out of the elements. This is my first winter after switching to lithium so I'll see if temp becomes an issue. If it does it'll be easy enough to keep the battery compartment warmer but I'll likely need to plug in to shore power to keep up with the draw.

This is the

$150 Elefast 12V 100Ah Bluetooth LiFePO4 Lithium Battery, BCI Group 24,Low Temperature Protection Up to 20000 Cycles, 1280Wh Energy LiFePO4 Battery in Small Size, Perfect for RV, Solar, Trolling Motor

house battery I'm running, with a Renogy 50a mppt/dc-dc charger, 200w of solar (mostly covered in the winter with a Thule box), and an X2 (Northstar) starting battery. Main draw on my system is the fridge but that doesn't have to work much in the winter. I have a Noco charger to top off the starting battery and house battery when I'm not driving much.

 

Update - I just bought a Antigravity 100ah lithium. Found they were 50% off for BF, but even cheaper on Amazon for some reason.

$449 Antigravity Batteries DC-100 V1 Performance LiFePO4 Deep Cycle Battery - 100Ah 12v Lithium BMS - Bluetooth Monitor, Heating - RV, Camping, Marine, Overland/Van, and Off Grid Applications

https://www.amazon.com/Antigravity-...sprefix=antigravity+100,automotive,140&sr=1-1

I have experience with their products for dirt bikes, and trust them a lot more than the no-name brands. We'll see how it turns out!

 

Got the Antigravtiy installed this past weekend, and been watching the bluetooth app to see what it's doing so far.

It was 10 degrees this morning, and on my 15min drive into the office, the battery heated up to 50 and was taking a charge. I assume it'll be solar charging while parked now. So seems like it's going to work without issue.

 

Tidied it up today and got the inverter back in. Hope I never have to work on this again for the life of the truck. Didn't leave myself much space.






Don't look too closely at my woodworking abilities @turbodb

 

Looks good. I see two circuit breakers in there. Why two, and what amperage are they?

 

100 amp for the 1000 watt inverter.

40 amp for the charger.

 

Is anyone still buying the Blue Sea ML-SCR? I started reading this thread from the beginning and they used to be very popular and were only about $150. Now they are twice the price and I don't see any mention of them toward the end of the thread.
I'm only interested in a dual battery setup for a winch, sound system and possibly an air compressor for on board air and air horns. I'm looking for a budget friendly solution yet I want to stay away from too much Amazon cheap components.

 

As someone running an ML-ACR, I can say that it's been great.

I think the reason you see it used less and less is twofold:

1. For most setups these days - like 95%, I'd say - a better solution than two AGM/lead acid batteries is to use a LiFePo battery for the house battery. With more usable energy, and lighter weight, it's just better for most camping needs.

2. The ML-ACR really shines when you can use an alternator to charge both AGM batteries. Because of changes to the charging system post-1st gen Tacoma, it's harder (though, not all that hard) to get charging voltages in the 14.5-14.7V range, which is what an AGM really needs. As such, it makes a lot more sense on 2nd, 3rd, and 4th gen Tacomas to use a DC-DC charger for the house battery. And, at the point you're using a DC-DC charger, a LiFePo battery becomes even more appealing.

Now, for your situation - winching - dual AGMs and an ML-ACR makes a lot of sense. Or at least, if you want to link two AGMs (with the ability to unlink them), an ML-ACR makes a lot of sense.

Personally, I wouldn't go that route anymore. I think the number of times you'll need linked AGMs for winching (in addition to the alternator, which I assume would also be running if you're winching for an extended period of time), is near zero. I've certainly never run into a situation where the alternator and a single AGM weren't enough (even though I have two). I've been involved in some pretty serious winching, too. This, for instance, required two trucks winching and two more as anchors. (trip report)

​

I'd recommend the LiFePo route with a DC-DC charger from Victron. It's the 2025 solution. I'm headed that way (probably this spring - May-ish), so if you're still looking for an ML-ACR then, I'd be happy to let mine go for cheaper than you can find them online these days. Oh, and it looks like the ML-ACRs aren't $150 anymore, but it's only $200 on amazon. Even less if you get "Used - Like New."

 

I'm running it in my 2nd gen and absolutely love it was my start to my dual battery setup.

 

I can get them through my company we are a blue sea dealer. Being in the boating industry I can get all things from blue sea at cost.

 

I will probably be upgrading the alt to a cs144. I'd do that before anything else. Maybe, all I need is a BIG battery and that alt then?

 

I upgraded to an agm battery but stepped down to a 24agm series battery its a marine Deka battery and I have had zero issues with it. You could step up to a bigger battery but keep in mind you will have to upgrade battery tray to keep from crushing a wheel well.