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

I went with the Victron SmartSolar MPPT 100/20. Absolutely love it! The app for it is super clean. One of the better android apps I've seen in awhile.

 

Thanks! Appreciate the help.

 

Would there be any adverse effects of running solar with ML-ACR, but 2 different batteries? 24F Lead Acid/35 AGM

 

Not a good idea on the batteries as they will kill each other.

I run solar with a ml-acr and it keeps them connected a lot more

 

I was told multiple times to use identical batteries when running an MLACR.. The technical reasons behind that are unknown to me though..

 

What if I ran the acr manually? On when truck is running and off when not?

 

No. The problem is the acr is a smart relay. Relays only connect the wires together.

If you were running a true isolator then it wound be fine as the batteries are never wired together.

there is nothing wrong with using a relay, the problem is wet cell battery and agm. They require different charging voltages, the chemistry is different and that’s how they fight each other.

 

Probably the best explanation of this problem I've heard on this forum. Thank you for making this simple and understanding.
Zim

 

Thanks for this. Guess I'll be picking up another AGM tomorrow.

 

It’s best to get them at the same time so there identical but I don’t think it matters that much. Main thing I wound focus on is same brand so the chemistry is nearly identical.

My setup I run a 2-3 year old yellow top optima with a ~10 year old blue top optima and have been running this for ~2 years now.

 

There were 3 on the shelf with the same date sticker when I bought my aux yesterday... so it should be the same.

 

Even better! But yea, the age thing isn't as big of a deal as some people make it out to be. I've ran a 4 year old agm with a brand new one and never had any issues. Keep the chemistry the same though.

 

Been reading through the thread and I must say it has a ton of good information. I am currently looking into a dual battery system and am up in the air on what I want exactly. I will be installing a VO Drifter next year which will is the main reason for going with dual batteries, that as well as the Dometic fridge. My thought was to have two completely separate systems, solar, a larger battery, and sub panel for the Drifter, and a larger battery for the truck, aux lighting, wench.

Should I link the batteries together?? If so, why and how?? I like the idea of being able to Jumpstart myself, but at the same time if I have two separate systems I shouldn't have to do so. Any advice, experience, and knowledge is welcomed. Thanks

 

I have a Drifter with lights on all four sides of it and inside top and bottom, as well as a fridge and water pump. The bigger amperage items like winch and air compressor are on my main battery. I use the ML-ACR connecting two Northstar batteries and two 100W solar panels connected to my aux battery, which is ultimately connected to my main battery via the ML-ACR.

If you are going to run two batteries, at the very least, give them capability of connecting if you aren't going to connect them at all times.

*edit* I also have a 250A High Output Alternator

 

Thanks for the info.. My plan was to leave the wench, compressor, and aux driving lights (front light bar, ditch lights, ect.) connected to the main truck battery, all of those goodies should only be used when the truck is running anyway. What type of charge controller are you running?? Where is you second battery located??

 

As discussed earlier in this thread, the 2nd and 3rd Gen Tacoma’s have smarter alternators that drop the charging voltage dramatically to save fuel. I have seen my 2015 2nd gen drop to 13.2. By the time you run that power to your six batter with and ACR, that 13.2 voltage might be in the 12v range. This will lead to an aux battery that will never fully charge. I would recommend looking into a DC -DC charger if you want to keep your battery for a long time. This will boost the lower voltage up to a proper charging voltage and follow a charge cycle correct for your battery chemistry.

If you have an older vehicle, this will be less of a problem because the charging voltage stays higher.

 

This is an old pic because I have Northstar batteries now, but you can also see in the picture the Blue Sea ML-ACR and a Blue Sea aux fuse panel for the truck accessories




Two 100W solar panels


Charge controller inside the cab. Super simple 30A controller. I think it was like $30 on Amazon. It's old now, so I'm sure there are a lot better options now.




And every accessory on the Drifter is connected to a separate Blue Sea fuse panel mounted inside the Drifter


And I made sure that all of the electrical in the Drifter had quick connects for when I need to take the camper off. Have only needed to take it off once though. I used a couple of different connectors because of the different wire gauges.


The wires go up this corner panel to the electrical track up top, then to back corner of the Drifter where the electrical panel is



Forgot to mention in my previous post that I also have a 250A High Output alternator as well.

 

So that is why I was leaning towards do two completely separate systems, it the aux battery is not connected to the trucks charging system then in theory it wouldn't strain the charging system and under charge. I would like to run the batteries linked together, but at the same time I feel the more components in the system the more problems/possible problems that can occur.

 

Thanks for the info and pics. System looks good, have you had any problems with the batteries under charging?? What gauge wire did you run to the rear for the camper panel??

 

I don't believe I have issues with under charging because of the upgraded alternator. I'm at 14.2V at idle and about 14.5 while driving. Side note, I drive like a grandma but got cut off bad once. Tried catching up, super high RPMs in the process, and the ML-ACR disconnected the batteries because of the built in safety feature it has

I used 2 AWG for the Drifter fuse panel, using the awg chart I posted in the previous page