The how's and why's of getting a booster pack to crank your 3.6L

OP
OP

Rahneld

Banned
Banned
First Name
Ronald
Joined
Jan 26, 2019
Messages
1,114
Reaction score
671
Location
Boston
Vehicle(s)
JL Wrangler
So is anyone going to spare us the long ass post and just put a pic of where to plug the booster lol. Holy crap that was a whole lot of info for a simple here plug your booster here.
So you don't want to know why it might work, just how to do it. Okay.

Connect the positive of the booster on to terminal N1 in the Power Distribution Center, and the negative of the booster on the collection of negatives cables connected to the main battery's negative post, only disconnect those negative cables first from that main battery's negative battery post before attaching the negative of the booster to those cables.

The, err, "long ass post" tried to explain the theory behind this. That takes words, especially for the unfamiliar. Sorry, not sorry.

In fairness, the post could have used pictures. Also in fairness, try explaining an chartered idea to the masses in ways all can understand Ruben. Then get shat on; see if you want to do that again. Just sayin'.
Advertisement

 

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
Oh I read the whole post. But you could have reversed it. Maybe like, here’s what to do, if you care to read why it works continue reading LOL.
 
OP
OP

Rahneld

Banned
Banned
First Name
Ronald
Joined
Jan 26, 2019
Messages
1,114
Reaction score
671
Location
Boston
Vehicle(s)
JL Wrangler
Oh I read the whole post. But you could have reversed it. Maybe like, here’s what to do, if you care to read why it works continue reading LOL.
Fair, but it seems odd if you read it that you'd need to ask. It's certainly clearly in there, even if stuck somewhere within the explanations.

Whatever.
 

Wabujitsu

Well-Known Member
First Name
Jeff
Joined
Jul 26, 2019
Messages
1,298
Reaction score
2,404
Location
Sarasota, FL
Vehicle(s)
2018 JLU Sport on 33s w/LSD, 2020 Sahara
Occupation
Retired US Army
Vehicle Showcase
1
In short (I apologize for not reading all six pages), how many cold volts and amps does it take to boost a dead start? What is the minimum, and what is the ideal? Thanks.
 
OP
OP

Rahneld

Banned
Banned
First Name
Ronald
Joined
Jan 26, 2019
Messages
1,114
Reaction score
671
Location
Boston
Vehicle(s)
JL Wrangler
In short (I apologize for not reading all six pages), how many cold volts and amps does it take to boost a dead start? What is the minimum, and what is the ideal? Thanks.
First, thanks for admitting Jeff to not reading, and being less gritty with questions than the prior poster.

I admit to not know the minimal amperage required to crank a 3.6L JL. Perhaps others do or it's posted someplace. Clearly, if one were acquiring a booster pack for their JL they would be wise make sure it meets, if not somewhat exceeds this threshold to accommodate for the lost of power a battery experiences over time and temperature, and the fact that if you use the technique above, for a short amount of time (i.e. the time between hooking the booster up, and running into the rig to attempt a crank) you are depleting that booster a tad in the process of charging the ESS/Aux battery.

I guess for argument sake you could remove the negative lead from the ESS/Aux battery, just as done for the main battery to get around this charging (or put such connections on an easily accessible switch) but that ESS/Aux battery is not trivial to get to, especially when out on the road.


This author considers that a better scenario than the charging of both batteries that a conventional jumping of the main battery terminals does, decreasing the chances that a booster will then have the "umph" to turn over the 3.6L JL.

As for ideal size--as I'm sure you can appreciate, lugging around one of those dealer 300 pound on wheels chargers, while sure to turn over your rig even if hooked up to the main battery terminals as per the manual, and allowing time for charging of the ESS/Aux battery to occur, isn't practical.***

(***In truth this approach charges both batteries, assuming they're capable of accepting charge, as they are connected in parallel when the rig is shut down.)

Does someone else know the minimal power required to crank a 3.6L JL?

Does someone have a sense of the extent to which manufacturers exceed cranking requirements with their batteries to account for power loss due to things like time and temperature?

If someone knows this Jeff, consider the chance that FCA *may* have made the requirements of the 3.6L JL's main battery closer (less reliable) to these thresholds than other vehicles, considering the fact that both batteries in the 3.6L are available to the cranking process.

Cheers.
 
Advertisement

Tri-City Jeep
 
Advertisement
Top