Overlanding battery

Lohkay

Well-Known Member
Joined
Jul 1, 2018
Messages
82
Reaction score
85
Location
Montreal
Vehicle(s)
JLUR
I hope someone can help me answer some questions in regards to adding an additional battery for my overland build.

I just finished a 2 week trial trip with most of my gear and with my 75l dometic fridge set on medium, I was going through the battery in around 15 hours which was fine as I was moving every day.

I would like to extend this time to 24 if not 48 hours so I wonder if I could add a second battery in the back, add an isolator up front and run wires to that second battery for charging.

I'm looking at a 200ah agm or lithium battery. Would that work? I have only rudimentary knowledge of car electric systems so I'm afraid I might forget something or do something wrong.

Thanx.
Advertisement

 

MORTON

Well-Known Member
Joined
Nov 11, 2018
Messages
4,112
Reaction score
5,993
Location
Florida
Vehicle(s)
JLU
Vehicle Showcase
1
I hope someone can help me answer some questions in regards to adding an additional battery for my overland build.

I just finished a 2 week trial trip with most of my gear and with my 75l dometic fridge set on medium, I was going through the battery in around 15 hours which was fine as I was moving every day.

I would like to extend this time to 24 if not 48 hours so I wonder if I could add a second battery in the back, add an isolator up front and run wires to that second battery for charging.

I'm looking at a 200ah agm or lithium battery. Would that work? I have only rudimentary knowledge of car electric systems so I'm afraid I might forget something or do something wrong.

Thanx.
Not to sure on this one but maybe @TTEChris can provide some guidance or know someone who can.
 

TTEChris

Well-Known Member
First Name
Chris
Joined
May 17, 2017
Messages
2,084
Reaction score
4,794
Location
Houston, TX
Website
www.tankcustoms.com
Vehicle(s)
2021 JTD & 2021 4XE
Vehicle Showcase
5

Jeff1

Well-Known Member
First Name
Jeff
Joined
Mar 3, 2019
Messages
101
Reaction score
52
Location
CT
Vehicle(s)
2019 JLUR
I'm not good with wiring electrical stuff so I went the portable power route. Picked up a Dometic PLB40 from REI a couple weeks ago. Not a cheap option but they had a 20% off coupon and I had a bunch of REI dividends and a couple gift cards so it was reasonable after all that. I haven't tested it in the vehicle yet but I should get 1-2 days or use with an ARB 37 fridge and it come with a car charger and wall charger. The other plus to it is that I can move it to other vehicles.
 

vavaroutsos

Well-Known Member
First Name
Pete
Joined
Nov 24, 2017
Messages
621
Reaction score
399
Location
Scotts Valley, CA
Vehicle(s)
2015 Sprinter Crew Van 2500 High Roof 144" WB OM651 Brilliant Silver, 2019 JLR 3.6L 6SPD Granite Crystal
There are a lot of options. A LiFePo4 battery will provide the best energy density and be the lightest, but charge management will be more complex. You will need four cells, a battery monitor, B to B charger, and contactor at a minimum. Or you can buy a pre-built LiFePo4 battery with protection and monitoring for quite a bit more money. A deep cycle AGM would be the simplest to setup with a charge control relay. Another option would be to replace your main battery with a dual purpose battery (starter & deep discharge), and add a solar panel and charge controller. I have two panels on top of my van (360 W total), and I have never had to plug in to shore power or charge from the alternator, but I am in NorCal.
 
Last edited:
OP
OP

Lohkay

Well-Known Member
Joined
Jul 1, 2018
Messages
82
Reaction score
85
Location
Montreal
Vehicle(s)
JLUR
There are a lot of options. A LiFePo4 battery will provide the best energy density and be the lightest, but charge management will be more complex. You will need four cells, a battery monitor, B to B charger, and contactor at a minimum. Or you can buy a pre-built LiFePo4 battery with protection and monitoring for quite a bit more money. A deep cycle AGM would be the simplest to setup with a charge control relay. Another option would be to replace your main battery with a dual purpose battery (starter & deep discharge), and add a solar panel and charge controller. I have two panels on top of my van (360 W total), and I have never had to plug in to shore power or charge from the alternator, but I am in NorCal.
Thank you for this thorough post. I had the intention to add solar panels eventually but I'm in Canada so the efficiency isn't there. I saw the pre-built LiFePo4 batteries and they are indeed pricey. I'll have to consider my options.
 

trav87

Well-Known Member
First Name
Travis
Joined
Apr 7, 2018
Messages
150
Reaction score
194
Location
PNW
Vehicle(s)
2018 JLU
Build Thread
Link
Vehicle Showcase
1
I'm running a deep cycle RV battery hooked up off a isolator. I can go 2 days stationary this way, but I'm noticing that I'm not getting a full charge, and it seems to be the electronic controlled alternator. I just ordered a Redarc DC to DC charger that works better with newer alternators and has input for solar charging, and will be ditching the isolator.
 

RubenZ

Well-Known Member
First Name
Ruben
Joined
Jun 24, 2018
Messages
1,767
Reaction score
1,619
Location
Deep South Texas
Website
myjlproject.com
Vehicle(s)
2020 Toyota Tacoma TRD Off-Road, 18’ Toyota 4Runner
Theres a guy not he Facebook JL Wrangler Group who added batteries in the rear cubby. I'm trying to get more info from him but they charge as he drives and uses them for his fridge and ARB pump. Heres a pic of the setup. I think it would be cheaper than the Genesis unit.

66309399_2283292848665506_2739098200269914112_n.jpg
 

vavaroutsos

Well-Known Member
First Name
Pete
Joined
Nov 24, 2017
Messages
621
Reaction score
399
Location
Scotts Valley, CA
Vehicle(s)
2015 Sprinter Crew Van 2500 High Roof 144" WB OM651 Brilliant Silver, 2019 JLR 3.6L 6SPD Granite Crystal
Theres a guy not he Facebook JL Wrangler Group who added batteries in the rear cubby. I'm trying to get more info from him but they charge as he drives and uses them for his fridge and ARB pump. Heres a pic of the setup. I think it would be cheaper than the Genesis unit.

66309399_2283292848665506_2739098200269914112_n.jpg
Looks like there is a charge control relay in there, something like this. This probably isn't the best solution with a smart alternator. Smart alternators won't generate sufficient charge voltage under normal conditions. Battery capacity is reserved and charge is dumped to the battery during braking under alternator control. This is done for fuel efficiency. To sufficiently charge a house battery a DC to DC converter needs to be used. Something like offered by Redarc or Sterling.
 
Last edited:

RubenZ

Well-Known Member
First Name
Ruben
Joined
Jun 24, 2018
Messages
1,767
Reaction score
1,619
Location
Deep South Texas
Website
myjlproject.com
Vehicle(s)
2020 Toyota Tacoma TRD Off-Road, 18’ Toyota 4Runner
Looks like there is a charge control relay in there, something like this. This probably isn't the best solution with a smart alternator. Smart alternators won't generate sufficient charge voltage under normal conditions. Battery capacity is reserved and charge is dumped to the battery during braking under alternator control. This is don't for fuel efficiency. To sufficiently charge a house battery a DC to DC converter needs to be used. Something like offered by Redarc or Sterling.
Wonder if instead of using the alternator one had solar panels on top roof rack? Then we'd be in business with a cost effective setup like that.
 

vavaroutsos

Well-Known Member
First Name
Pete
Joined
Nov 24, 2017
Messages
621
Reaction score
399
Location
Scotts Valley, CA
Vehicle(s)
2015 Sprinter Crew Van 2500 High Roof 144" WB OM651 Brilliant Silver, 2019 JLR 3.6L 6SPD Granite Crystal
Wonder if instead of using the alternator one had solar panels on top roof rack? Then we'd be in business with a cost effective setup like that.
You can do that, but then you need a solar charge controller (MPPT is best) which costs about the same as a DC to DC. Redarc does make a combo unit for about $100 more if you want both alternator and solar charging. Victron makes some nice solar chargers.
 

moodywizard

Well-Known Member
First Name
Lyle
Joined
Apr 23, 2019
Messages
430
Reaction score
338
Location
California
Vehicle(s)
2019 JLUR
I just posted a thread in the 3.6 section, I have the genesis daul battery kit and noticing inadequate charging as well given certain circumstances.. Wonder if there is a way to have the alternator charge at 14V constantly?
 

vavaroutsos

Well-Known Member
First Name
Pete
Joined
Nov 24, 2017
Messages
621
Reaction score
399
Location
Scotts Valley, CA
Vehicle(s)
2015 Sprinter Crew Van 2500 High Roof 144" WB OM651 Brilliant Silver, 2019 JLR 3.6L 6SPD Granite Crystal
I just posted a thread in the 3.6 section, I have the genesis daul battery kit and noticing inadequate charging as well given certain circumstances.. Wonder if there is a way to have the alternator charge at 14V constantly?
The ECU controls the charging, so it's not likely an easy fix. Probably a question for @[email protected].
 

LincolnSixAlpha

Well-Known Member
First Name
Brian
Joined
Oct 26, 2018
Messages
351
Reaction score
271
Location
Arizona
Vehicle(s)
2018 Jeep Wrangler Unlimited Rubicon
Vehicle Showcase
1
Not sure if this helps but genesis offroad makes a dual battery kit for the JL. I have never had the need for a dual battery setup, so don't know much beyond what I've seen on the market.
https://www.genesisoffroad.com/JeepJLDualBattery-p/185-jldbk.htm

For what it's worth, I installed the genesis dual battery system. Not terribly difficult to install, but a bit time-consuming. Their installation video is spot on. The best part is that it eliminates that little motorcycle battery under the fuse box. Quality components as well. I have an ARB fridge and recently returned from a trip to the Canadian Rockies. I'm mobile during the day, but have gone 16+ hours running on the batteries, and have no fear now about running the batteries down since the second will disconnect the two batteries at a certain level (12.4, or 12.7 v, cannot remember).

If I had to speculate, you could easily get 36 hours or more out of this setup. I'm just not still enough to test beyond the 16 hours I was not mobile.
 

LincolnSixAlpha

Well-Known Member
First Name
Brian
Joined
Oct 26, 2018
Messages
351
Reaction score
271
Location
Arizona
Vehicle(s)
2018 Jeep Wrangler Unlimited Rubicon
Vehicle Showcase
1
I just posted a thread in the 3.6 section, I have the genesis daul battery kit and noticing inadequate charging as well given certain circumstances.. Wonder if there is a way to have the alternator charge at 14V constantly?
What's the bead on this? I noticed that the JL was constantly sitting at 14+ volts attempting to charge these two batteries. However, since returning from my very long trip to the Rockies and about (5K + miles) this seems to be no longer the case, as the voltage settles down within an hour or two.
 
Advertisement

Jim Marsh Chrysler Jeep
 
Advertisement
Top