When do you go dual battery?

A

Aznisegi

New member
So, I've been toying with dual batteries, but I don't know exactly when I really need it. The extra items I run will be

1x 40" rigid lightbar
1x 30" rigid lightbar
2x diffused rigid flushes
1x winch
2x side diffused rigid sr-qs
2x rigid pods up front
1x front camera

At what point should I consider dual battery, or am I already at that point?
 
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Aznisegi said:
So, I've been toying with dual batteries, but I don't know exactly when I really need it. The extra items I run will be

1x 40" rigid lightbar
1x 30" rigid lightbar
2x diffused rigid flushes
1x winch
2x side diffused rigid sr-qs
2x rigid pods up front
1x front camera

At what point should I consider dual battery, or am I already at that point?
Click to expand...

I'd say when you add a fridge. You could run all that with a larger Group 31 battery and an electrical management system like an sPOD or SwitchPro. It's not like you'd be running all of those lights for days on end without the car on anyways. Until you add a load that is constantly on for days with the car off then you probably don't need a second battery.
 
sn_85 said:
I'd say when you add a fridge. You could run all that with a larger Group 31 battery and an electrical management system like an sPOD or SwitchPro. It's not like you'd be running all of those lights for days on end without the car on anyways. Until you add a load that is constantly on for days with the car off then you probably don't need a second battery.
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Agree 100%. Fridge running all the time requires battery #2.
 
you can run a fridge on a single battery you just need a dual purpose battery with more capacity. even in the summer my 31m will run my fridge for at least 2 days on the high setting, and 3 days if I put it on the medium setting (the truck will still start at that voltage, but I don't like trusting that)

I would say you only need a second battery if load calculations show you don't have capacity to run the equipment you want for the time you want, or if you do remote solo travel and want redundancy and the ability to do longer winch pulls
 
As said above, when you get a fridge or something that you will be running when the engine is off.

I upgraded to a dual battery since I often go camping in remote areas with just the one vehicle, and I don't want to get stranded with a dead battery. With two batteries, I can blast music and have the fridge and lights running all night with no fear about whether or not my engine will turn over in the morning.

You can run a fridge with one battery, but I just don't trust that for being off on my own with no cell service and many miles from any help.
 
A second battery doesn't give you more generating ability. So anything that you run while you're driving should not need a 2nd battery. If you're alternator is not keeping up - you have an alternator problem rather than a battery problem. Batteries don't like to be drained more than half way on a regular basis, that's very hard on them. So the time you want to upgrade is if you're doing something that drains them more than half way.

The typically example is some sort of electric device that will run when the vehicle is not running and use more than about 200 watt hours before you run the vehicle again (drain more than half the battery). A typical fridge uses about 1 amp per hour - or about 12watts per hour. So if you're running your fridge for more than 16hrs between running your engine - it's probably a good idea to either go for a dual battery or upgraded capacity. That's when most people upgrade.

IMO a 100W solar panel and MPPT charger is a better way to spend your money before adding a second battery. I have a camp trailer where my fridge lives most of the time. I've never run out using a single deep cycle battery and 100w solar panel for the fridge, the sink, the lights, radio, charging phones, etc. The single 100w solar panel more than tops off the battery every day - so it can run indefinitely. Even at home I just leave the solar panel exposed and it's always ready to go and fully charged. I didn't add a second battery to my trailer until I upgraded the inverter to run my air conditioning in the camper.

Or you have a short duration load that exceeds about 5,000 watts on a regular basis, or you have a medium duration load that exceeds 1000 watts that will drain the battery more than half way while still running. This is something like using your winch for multiple back to back full line pulls. I'm not sure if you can outrun the alternator doing this. I've never tried. I'm confident that you can outrun the alternator using a commercial snow plow. On all of my plow trucks I use dual or triple battery sets. That way they can charge while driving between jobs and not run out of juice. But that's a pretty rare scenario.
 
Antman said:
Agree 100%. Fridge running all the time requires battery #2.
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You're an idiot...

e60ral said:
you can run a fridge on a single battery you just need a dual purpose battery with more capacity. even in the summer my 31m will run my fridge for at least 2 days on the high setting, and 3 days if I put it on the medium setting (the truck will still start at that voltage, but I don't like trusting that)

I would say you only need a second battery if load calculations show you don't have capacity to run the equipment you want for the time you want, or if you do remote solo travel and want redundancy and the ability to do longer winch pulls
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Agreed....

I run almost all the stuff OP is running, plus small Dometic 24/7...PLUS the Dometic CFX 65 when camping, and only rely on the 100 watt Renogy panel on the roof to keep the Northstar gp 31 topped off.

If I get stuck I carry a li-ion jump pack...no issues to date.

Don't have the weight and expense of the having and installing a second battery.
 
Titanpat57 said:
You're an idiot...



Agreed....

I run almost all the stuff OP is running, plus small Dometic 24/7...PLUS the Dometic CFX 65 when camping, and only rely on the 100 watt Renogy panel on the roof to keep the Northstar gp 31 topped off.

If I get stuck I carry a li-ion jump pack...no issues to date.

Don't have the weight and expense of the having and installing a second battery.
Click to expand...


Your mom goes to college...
 
Antman said:
Your mom goes to college...
Click to expand...

I’m with your girlfriend on this one... :crybaby:

I’ve had my fridge for 2 1/2 years with a solo battery, I carry an Antigravity jump pack which I’ve used more to start other people’s cars than mine.
 
Jhalko said:
I’m with your girlfriend on this one... :crybaby:

I’ve had my fridge for 2 1/2 years with a solo battery, I carry an Antigravity jump pack which I’ve used more to start other people’s cars than mine.
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Well you guys can just snuggle up together with your battery packs.

I can tell you I have used my second battery to emergency start my truck exactly 5 times since I've set it up. I run my fridge 24/7 though. Hot days drain the battery pretty quickly!
I would rather just flip a switch to self start than have to store and maintain a battery packs charge, get out and hook it up and all that. Just me.

PS- go to the Dr when you and Pat are done. Bastard gave me Herpes twice now...
 
Antman said:
Well you guys can just snuggle up together with your battery packs.

I can tell you I have used my second battery to emergency start my truck exactly 5 times since I've set it up. I run my fridge 24/7 though. Hot days drain the battery pretty quickly!
I would rather just flip a switch to self start than have to store and maintain a battery packs charge, get out and hook it up and all that. Just me.

PS- go to the Dr when you and Pat are done. Bastard gave me Herpes twice now...
Click to expand...

how long are you parking? does your fridge not have a voltage protect? if you have 2 batteries why is your fridge or anything killing your starter battery? i also run mine 24/7 but i've only had to use my jump pack for other people, it's a lot easier than carrying cables.
 
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e60ral said:
how long are you parking? does your fridge not have a voltage protect? if you have 2 batteries why is your fridge or anything killing your starter battery? i also run mine 24/7 but i've only had to use my jump pack for other people, it's a lot easier than carrying cables.
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Jesus- am I being grilled here or what? lol

It has voltage protect but I have it off. I don't want my stuff to go bad in there and when I shop at work I want the fridge to be cold for the ride home. I work a lot of hours man, so it sits!

Anyway- the other issue is that the Alt won't ever fully top off my Dual Purpose 27 main battery so it gets weaker and weaker every day. If I use the onboard charger regularly it's much better; both batteries stay topped off.

Many ways to skin a cat- this is my way and I like it.:biggrin1:

Oh- 1 more thing...

My setup is different than most. I have a big main Battery that is connected in the factory location- the fridge runs off of that too. My backup battery is smaller and is only there to start the motor if the main dies. Basically flip a switch, they connect, truck starts. I can control the charging with the switch too and I have status indicators for both to let me know what's going on.
Antman's Dual Battery Setup
 
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ah, so essentially a single dual purpose battery setup but instead of a jump pack you just carried an entire backup lead acid battery
 
Antman said:
Agree 100%. Fridge running all the time requires battery #2.
Click to expand...

Titanpat57 said:
You're an idiot...



Agreed....

I run almost all the stuff OP is running, plus small Dometic 24/7...PLUS the Dometic CFX 65 when camping, and only rely on the 100 watt Renogy panel on the roof to keep the Northstar gp 31 topped off.

If I get stuck I carry a li-ion jump pack...no issues to date.

Don't have the weight and expense of the having and installing a second battery.
Click to expand...

Antman said:
Your mom goes to college...
Click to expand...

Antman said:
Well you guys can just snuggle up together with your battery packs.

I can tell you I have used my second battery to emergency start my truck exactly 5 times since I've set it up. I run my fridge 24/7 though. Hot days drain the battery pretty quickly!
I would rather just flip a switch to self start than have to store and maintain a battery packs charge, get out and hook it up and all that. Just me.

PS- go to the Dr when you and Pat are done. Bastard gave me Herpes twice now...
Click to expand...

HAHAHHAHHAHAHAHHA OMG!!! I miss you guys!
 
+1 on the 2nd battery with the fridge. Actually I don't think I'll ever think about running the ARB fridge/ freezer on a single battery setup.
 
You should remember that the batteries are technically only really there to start your car and the alternator is used to create the power needed for your cars utilities. Although this is not completely true obv, as many people use things that put amp draw on your batteries while your car is off. Often a better option then buying a second battery, is to buy a better battery. One big reason for this is, when you have a dual battery setup, you should use identical batteries of the SAME AGE. This prevents one battery from draining the other lesser battery. I recommend NorthStar batteries. If you get one large and expensive AGM battery you will likely have plenty of power. You should probably do rough calculation of your current draw needs and compare to the battery capabilities. ALSO, the more batteries you have, the more your alternator has to work to keep them charged, so if you upgrade/add batteries, you technically should upgrade your alternator (not many cheap high output alt options for 4runners). But if you upgrade your alternator, you wont need to upgrade your battery unless you need to draw power while the car is not running.
 
A little boost...

Jeffy said:
As said above, when you get a fridge or something that you will be running when the engine is off.

I upgraded to a dual battery since I often go camping in remote areas with just the one vehicle, and I don't want to get stranded with a dead battery. With two batteries, I can blast music and have the fridge and lights running all night with no fear about whether or not my engine will turn over in the morning.

You can run a fridge with one battery, but I just don't trust that for being off on my own with no cell service and many miles from any help.
Click to expand...

Agreed. Just bought one of these on Amazon today.

Battery Starter for Car, TOPVISION 2200A Peak 20800mAh Portable Car Power Pack with USB Quick Charge 3.0 (Up to 7.0L Gas or 6.5L Diesel Engine), 12V Portable Auto Battery Booster
 
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