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

Honestly, depending on your dual battery setup, with the ignition on, you'll likely be reading alternator voltage output much of the time instead of the battery. This is why with the ignition off, you'll see a true voltage of the batteries. Also be careful with losses in the lines or trying to read off of the power while another device is running. I had a voltmeter mounted in the back of my topper, but I tied it to the feed of other things, it shows a dip in voltage with other stuff turning on and off. I ended up running independent hot and ground to each main and aux.

 

I am ordering parts for a dual battery setup (both in the engine bay) with a Blue Sea ML-ACR.

What wire gauge do you guys recommend to connect the batteries?

Also, Do any brick and mortar stores carry good welding wire? I've got a good online source, but shipping is expensive.

I know I could get wire from West Marine, but I don't know if it would be as flexible.

 

Home Depot should have the wire you need- it’s on their bulk racks

 

anyone know about these? https://www.amazon.com/gp/product/B00C2DZP4O/ref=ox_sc_act_title_2?smid=A3H30ATSR61H8N&psc=1

 

Need info on group buy please

NM I missed it.

 

Hello guys i'm trying find any information on a secondary battery location for the 1st gens any links or pics that someone could share thanks in advance

 

Blue Sea ML-ACR Wire Gauge

I see a lot of people using 1/0 gauge when connecting to a battery in the bed.
A user in this thread who had the batteries next to each other used 4 gauge.

What is the general consensus for batteries in the same engine bay but on different sides?
I want to use 2 awg but am not sure if that will be big enough.

 

Be certain to fuse the connections, but honestly, it's all about powerloss over distance and the amount of current you push.
http://circuitwizard.bluesea.com/
The above site is a pretty good tool.

 

I have a battery on each side of he engine bay and used 2awg. It’s perfectly fine. Personally 4awg is getting a little small to feed the starter, but factory is somthing like 5awg. The longer the run the thicker the wire you want. So in the bed you wound want a 1/0 or larger because of wire resistance.

As I was building/wiring mine I started the truck only off the aux battery running 2awg to the stock location

I wound not fuse your system if you will be using the aux battery to self jump.

 

I fused at 200 amps, there are limitations on what the ML-ACR can pass.

 

200A is the max of some other isolaters, the ml-acr is meant to be able to pass starting voltages
500A for continuous duty. It can peak at 1450A for 30 sec or 700A for 5 min

 

All of what you say is entirely accurate, I would also look at the max charging current for your specific batteries. My Renogy 200AH AGM battery has a max charging current of 80A, though a discharge current of 2000A for 5s. My personal opinion and the biggest reason I fuse my leads, if a wire gets abraided somehow and grounds, I may prevent a fire or damage to the battery or other things. To each their own, as far as jump starting, it may take longer with the fuses or I could bypass with jumper cables.

The only thing I haven't fused is the winch, but that requires large draws, so any fuse would be ineffective relative to the battery. I did however isolate the winch with a solenoid.

 

Just realized I have 4 batteries sitting in my garage from October -April. When I put my boat away for the year they sit on a trickle charger. Be nice to have a extra battery during hunting season and cold weather.
Is there a simple way to hook up a second battery that doesn’t require charging equipment, monitors, switches, upgraded alternator?

 

Depends on what type of battery. You should not need an upgraded alternator, what do you want to do with it? What's the plan for the second battery?

 

Also true. Lol depends on your reason for haveing the second battery. Mine was for self jump. Yours sounds more for extra accessories.

While I dident fuse my wire runs, I crimped the ends, used heat shrink, and added a abrasion resistant wire loom for the whole run.

 

Just too have a back up really. It’s a marine battery for electric trolling motors. I’m looking to just keep a charge on the second battery. If need be I can unhook the dead battery and hook up the fresh one. I’m looking for a low tech method.

 

So, run a 6 awg wire to the back and get a solenoid or heavy duty switch at the main battery. You’ll have to wire the solenoid to a circuit that is on when truck is on. Or the switch you’d have to go turn it on and off every time.

Another option is wire in with 6 or 4 gauge an Anderson plug in the rear to plug in the extra battery

 

Certainly sounds like you did it right. Applications vary.

 

I've read all 99 pages and learned more than I thought. I already had a fuse block and relays setup under my hood and there is not enough room for two 27f yellow tops. I mounted the second battery in the bed and ran 0 to the engine bay. Since the power consumption for my block is rated to require 4 gauge and I ran 0 gauge would it be ok to use the same wire to feed the fuse block from the battery in the bed or do I need a second line from aux batt to fuse block?

 

You can run it all off the same line