The JL got two batteries. Does it make sense?

[Sean L]

Does everyone just ignore the 15 other threads on this same topic?

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[macintux]

Does everyone just ignore the 15 other threads on this same topic?

I'M OUTRAGED AND I MUST POST THIS RIGHT NOW.

 

[TexTJ209]

I believe we will find out that JL engineers know what they are doing.
The ESS battery will be isolated, only being used for ESS. (easy to do)
I speak from 40 years as an aerospace engineer... not Joe Blow

Speaking as a Mech. Eng , you'd be surprised at how often factory dual battery setups are not isolated. This may not be the case here, but bean counters are always involved and two dead batteries is one more battery that the dealer can sell you. Hopefully, they did it right but i'm doubtful. More realistically, hopefully, the diesel won't have this "feature" so I don't have to worry about it.

 

[digitalbliss]

Here is a video confirming what @FatBoy01 told us about the two batteries as it relates to starting your Jeep.

 

[drogers]

Speaking as a Mech. Eng , you'd be surprised at how often factory dual battery setups are not isolated. This may not be the case here, but bean counters are always involved and two dead batteries is one more battery that the dealer can sell you. Hopefully, they did it right but i'm doubtful. More realistically, hopefully, the diesel won't have this "feature" so I don't have to worry about it.

The only dual battery setups I’m familiar with that aren’t isolated are on big diesels, and feature identical batteries. These two are obviously of a much different capacity, and probably C as well - not isolating those two would kill one or the other in a matter of months.

 

[TIDALWAVE]

"digitalbliss"...does this mean that the smaller battery is used as the 'starter battery' for the JL? If so, I dread trying to start my new Rubi when it has been sitting outside in the middle of the winter and temp is -25F!

 

[RussJeep1]

So, your dependent on a motorcycle battery to start your rig....that doesn't even display a diagnostic code when dying or dead, other than you vehicle won't crank even though the rig's got juice for the electrics...that correct me if I am wrong, we don't know if the two batteries are isolated, and......

if this small battery is dead, can you even jump start?

Could someone test if the batteries are isolated and if not recommend a kit to do so, or the downsides of doing so?

Would (I don't know where it would fit yet) putting in two full size batteries like some people have done on their JK's and getting rid of this small battery work?

Why was this done...is it easier to charge two batteries than one large one?

Is this a standard motorcycle like battery...do we know its life span, etc.

Please someone come up with a fix to trick the rig into thinking the small battery is working when its not.

Maybe I need dual small batteries??!!

 

[BillyHW]

So, your dependent on a motorcycle battery to start your rig....that doesn't even display a diagnostic code when dying or dead, other than you vehicle won't crank even though the rig's got juice for the electrics...that correct me if I am wrong, we don't know if the two batteries are isolated, and......

if this small battery is dead, can you even jump start?

Could someone test if the batteries are isolated and if not recommend a kit to do so, or the downsides of doing so?

Would (I don't know where it would fit yet) putting in two full size batteries like some people have done on their JK's and getting rid of this small battery work?

Why was this done...is it easier to charge two batteries than one large one?

Is this a standard motorcycle like battery...do we know its life span, etc.

Please someone come up with a fix to trick the rig into thinking the small battery is working when its not.

Maybe I need dual small batteries??!!

FCA is on like the 7th edition of the owner's manual, and while they've been working extra hard to write, and then remove all traces of the Off-Road Pages, they still haven't gotten to writing a section about the dual battery system. Maybe by 2021 we'll have something in the 39th edition Rev 4.

I still don't know if we can even trust the jump start procedure in the new manual. I think they just copied over those sections from the JK, and none of the engineers told the documentation people about it yet.

I don't know if there's an isolator between the two batteries, but I think there are at least switches and relays between them that can join or isolate the batteries depending on the circumstances of the ESS system.

Dual full-size batteries will fit, but in a group 25 size. The Genesis kit that I am aware of gets rid of the smaller battery. Wiring them so that nothing else breaks and you still get the normal benefits of an isolated dual battery system is going to be a challenge, and I don't know how that's going to work yet.

 

[RussJeep1]

FCA is on like the 7th edition of the owner's manual, and while they've been working extra hard to write, and then remove all traces of the Off-Road Pages, they still haven't gotten to writing a section about the dual battery system. Maybe by 2021 we'll have something in the 39th edition Rev 4.

I still don't know if we can even trust the jump start procedure in the new manual. I think they just copied over those sections from the JK, and none of the engineers told the documentation people about it yet.

I don't know if there's an isolator between the two batteries, but I think there are at least switches and relays between them that can join or isolate the batteries depending on the circumstances of the ESS system.

Dual full-size batteries will fit, but in a group 25 size. The Genesis kit that I am aware of gets rid of the smaller battery. Wiring them so that nothing else breaks and you still get the normal benefits of an isolated dual battery system is going to be a challenge, and I don't know how that's going to work yet.

Billy: can someone say, "aftermarket manufacturer opportunity!"

 

[TIDALWAVE]

The thread with the Youtube video showed which power leads connected to which battery. He then proceeded to show that the smaller ESS battery is the starting battery. Could we switch the power leads from the two batteries if the ESS battery were to die? The system shouldn't know which battery is which as long as they feed 12VDC.

 

[BillyHW]

The thread with the Youtube video showed which power leads connected to which battery. He then proceeded to show that the smaller ESS battery is the starting battery. Could we switch the power leads from the two batteries if the ESS battery were to die? The system shouldn't know which battery is which as long as they feed 12VDC.

Hey, good idea. I wonder how hard it is to do that though.

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