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Discussion Starter · #1 ·
If you don’t already know about the blended braking system on the Wrangler 4XE, this video might make you question the validity of using Max Regen on a daily basis.

Also, did you know that the Wrangler 4XE is both a series hybrid and a parallel hybrid depending on conditions? I don’t quite understand the conditions yet but I stumbled on it happening during this video and decided to talk about it.

Also, this video contains an idea for a group project. Looking for some creative electrical engineering help.
 

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Really interesting. So without Max Regen on, is the braking still recharging the battery? I take it that it is. Basically, without the Max Regen on, you’re still saving the wear on the physical brakes as long as you’re not braking too aggressively. And recharging the battery. Yes??
 

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Discussion Starter · #3 ·
Really interesting. So without Max Regen on, is the braking still recharging the battery? I take it that it is. Basically, without the Max Regen on, you’re still saving the wear on the physical brakes as long as you’re not braking too aggressively. And recharging the battery. Yes??
Exactly. I got a little inside information about the blended braking and that the friction brakes don’t kick in until the last little bit of a normal stop. In heavy braking or if the vehicle senses wheel slip, the friction brakes kick in. But under normal driving, that’s all regen we’re feeling until the vehicle needs to come to a complete stop.
 

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Just watched, his has actually been one of my biggest curiosities on the platform! People have been reporting better efficiency without max regen. I was thinking it may be human intelligence vs. FCA sensors/programming. Also, why did they disable it as default?

I figured braking should always use regen when it can until physically it is needed. But Max Regen is moderately aggressive and may result in situations where too much momentum is lost, thus resulting in needing to recover that momentum.
 

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Discussion Starter · #5 ·
I think everything you said is spot on.
The Max Regen is supposed to be latching so it should always be in whatever state you left it in. An update should be coming soon to put the latching back in.
 

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If you don’t already know about the blended braking system on the Wrangler 4XE, this video might make you question the validity of using Max Regen on a daily basis.

Also, did you know that the Wrangler 4XE is both a series hybrid and a parallel hybrid depending on conditions? I don’t quite understand the conditions yet but I stumbled on it happening during this video and decided to talk about it.

Also, this video contains an idea for a group project. Looking for some creative electrical engineering help.
Never mind, LOL! Wasn't paying attention. First, unrelated question... how'd you get the Jeep background on your screen?

Second, related comment... my first two weeks, I did not use MaxRegen on my daily commute to work. It's about 4.3 miles, speeds between 30 - 35, with slight hills. I could get to work using about 20% of my battery. Last week, I started turning MaxRegen on and I noticed it would only take 17% or so to make it to work. No idea what that means but just thought I'd share.
 

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Discussion Starter · #7 ·
Never mind, LOL! Wasn't paying attention. First, unrelated question... how'd you get the Jeep background on your screen?

Second, related comment... my first two weeks, I did not use MaxRegen on my daily commute to work. It's about 4.3 miles, speeds between 30 - 35, with slight hills. I could get to work using about 20% of my battery. Last week, I started turning MaxRegen on and I noticed it would only take 17% or so to make it to work. No idea what that means but just thought I'd share.
That’s good information.
 

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Never mind, LOL! Wasn't paying attention. First, unrelated question... how'd you get the Jeep background on your screen?

Second, related comment... my first two weeks, I did not use MaxRegen on my daily commute to work. It's about 4.3 miles, speeds between 30 - 35, with slight hills. I could get to work using about 20% of my battery. Last week, I started turning MaxRegen on and I noticed it would only take 17% or so to make it to work. No idea what that means but just thought I'd share.
Thanks, others have reported the opposite.

I figure it's easier to accidentally slow down too much in max gen and the worst thing is to lose momentum you need. Took me a bit until someone pointed out that lite throttle will still regen, which makes timing in traffic easier.

Something else I was reading is that EVs can't regen with a full battery. This combined with high charge resistance at capacity is probably why e-save doesn't work over 95%.

On the topic of regen, when in a 4WD mode the hybrid screen shows the front wheels regenerating but not in 2WD. This doesn't make sense to me as I doubt the front regen brakes are not working.
 

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Discussion Starter · #9 ·
Thanks, others have reported the opposite.

I figure it's easier to accidentally slow down too much in max gen and the worst thing is to lose momentum you need. Took me a bit until someone pointed out that lite throttle will still regen, which makes timing in traffic easier.

Something else I was reading is that EVs can't regen with a full battery. This combined with high charge resistance at capacity is probably why e-save doesn't work over 95%.

On the topic of regen, when in a 4WD mode the hybrid screen shows the front wheels regenerating but not in 2WD. This doesn't make sense to me as I doubt the front regen brakes are not working.
Regen doesn’t happen in the brakes. I know it’s called regenerative braking but the electric motor in the transmission is where regen comes from. The only thing at the wheels are the friction brakes.
 

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Ah yes, so in 2H they are not engaged. I've felt some different characteristics. In 4H Auto stops feel a little more aggressive or responsive.

Pulling into my garage in 4H is a very different than in 2H.
 

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Another thing I noticed, when using max regen to slow down, the brake lights do NOT come on! Like most, I also get better distance NOT using it. I’ve figured out that I can coast quite a ways. With max regen on, I can’t. So I’m having to give it more “gas” to further.
 

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Another thing I noticed, when using max regen to slow down, the brake lights do NOT come on! Like most, I also get better distance NOT using it. I’ve figured out that I can coast quite a ways. With max regen on, I can’t. So I’m having to give it more “gas” to further.
I was wondering about the brake lights not coming on. Not good! I don’t think I’ll be using this as often anymore.
 

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Exactly. I got a little inside information about the blended braking and that the friction brakes don’t kick in until the last little bit of a normal stop. In heavy braking or if the vehicle senses wheel slip, the friction brakes kick in. But under normal driving, that’s all regen we’re feeling until the vehicle needs to come to a complete stop.
This may be exactly why they switched to the Max Regen not being sticky, they want to make it more of a special use case, vs. the default.
 

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It all comes down to driving style. The only difference is where your foot is.

From what I have observed so far.....
With Max Regen off, there is no regen unless you lift your foot off the accelerator. That would be mild regen. More regen occurs by moving your foot to the brake pedal. The more pressure you apply the more regen up to the limits of the motor and battery pack. After that point the friction brakes blend in.

With Max Regen on, the driver can Accelerate, Coast or Decelerate(regenerative braking) all with the same pedal. If you need more braking than the motor can deliver then you need to move your foot to the brake pedal. At that point the friction brakes blend in (because you are at max regen already).

Regenerative braking occurs either way. It just depends on how much you want to move your foot around.

In 2H, only the rear wheels will drive the motor so all the energy recovered comes from the rear wheels.
In 4WD, the energy recovered comes from all wheels.

There is a certain amount of energy required to complete each stopping event. It is possible to recover a large percentage of that energy depending on the rate of deceleration, motor size, battery capacity and temperature. It varies. If you leave Max Regen on than the car figures it out for you. It is possible to recover the same amount of energy by using the brake pedal so Max Regen isn't required. It really depends on your driving style, conditions, traffic etc.

I like having the choice and am glad Jeep put that button there. :)
 

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Ya, a good question for sure. I live in CO, so I’m often driving mountain roads and we just got a place up the canyon from town. I tried using the mode the other day coming down the canyon, but it just slowed me down too much.
So what you’re saying is if I’m coasting downhill in max regen mode, it just looks like I’m riding my brakes the entire time? Not so great, and I’m sure I’d get more than a look or 2…still trying to figure out when using this feature would make the most sense and be safe to use so that other drivers behind aren’t adversely reacting if the brake lights are constantly lit.
It seems it would only be useful in stop/go traffic? But sounds like the gains are really negligible? Maybe not if you lived in L.A…..


Sent from my iPhone using Tapatalk
 

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I think stop and go traffic is the best use case for max regen. It honestly almost is safer because you start to break that instant. I had one person cut me off and I was thankful max regen mode was on then. otherwise I think they realized that max regen mode isn’t the modest efficient mode for most driving - especially hilly areas where coasting momentum is far more efficient.

Related to the parallel hybrid driving mode mentioned, I finally experienced it for the first time when I got up over 70 mph or so. I drove more miles and used up almost 10% less battery for my commute and I still was getting about 35 instant mpg. (Usually my commute is max 60 mph but a chunk of road is having construction so I had to take a detour).
 

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In my test using max regen and then leaving it off, I fare better with it turned on.

I have a 20 mile commute to work. Varied driving with highway 60 mph, stop and go and some in between.

With max regen turned on I get to my 20 mile trip with about 6-8 miles left. Almost exactly what I have actually driven.

With max regen off, I get to work with 1-2 miles left on battery.

Just my experiences so far.
 
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