Chris Hall
Well-Known Member
- First Name
- Chris
- Joined
- Oct 19, 2020
- Threads
- 21
- Messages
- 144
- Reaction score
- 401
- Location
- Clayton, Ohio
- Vehicle(s)
- Smart Electric Drive, Wrangler 4XE coming soon.
- Thread starter
- #1
After driving the Wrangler 4XE for a while, I've started to create a mental image of how I perceive the software prioritizes power use. There's a lot going on in the software. The amount of code must be amazing. This is nothing official and I have no access to the actual data. I have just been observing the power flow screen as I drive and have attempted to give it a graphic representation of what I see the vehicle doing.
One primary thing to understand is that the Wrangler 4XE is always a hybrid. I'll say it again: The Wrangler 4XE is always a hybrid. It is always working to maximize efficiency while maintaining power.
In hybrid mode when the battery is charged, the vehicle places a high priority on operating in all electric but will add the gas engine for added power when there is a demand. If the driver pushes the accelerator pedal just a little bit more than "normal" when leaving a stop sign, the gas engine will kick on to respond to driver input.
In Hybrid Mode when the battery is depleted to the "<1%" point the vehicle becomes more like a non-plug-in hybrid. It's primary source of propulsion is the gas engine but it uses the electric motors when possible. It maintains a state of charge around 15% that is hidden from view by the indicator on the dash. The vehicle will recapture energy when decelerating or going down hills via regeneration. Even with Max Regen turned off, the vehicle still regenerates when possible. It will also lightly charge via either the eTorque motor/generator or the Traction motor/generator in the hybrid transmission.
In Electric Mode, the vehicle places a high priority on operating on electric only but will turn on the gas engine when there is a power demand. Remember, it is always a hybrid. As such, Jeep has balanced efficiency and performance. While the gas engine will not kick on under the same kind of demand rate as when in Hybrid mode, the driver can still get the gas engine to kick on if they place a high enough demand on the system.
The e-Save mode is possibly the most misunderstood mode of the vehicle. Let me restate the phrase that the Wrangler 4XE is always a hybrid before I go on. In e-Save mode, the operator has a choice between Battery Save and Battery Charge. With battery save mode, we might believe that it places the Wrangler 4XE is "Gas Mode" and the battery just sits there. By observing the power flow screen in the Uconnect, we can see that this isn't the case. The battery is still made available for hybrid operation but it's application is lessened. Much like how the vehicle maintains the battery at 15% in the background when the SOC indicator hits <1%, the vehicle will maintain the battery at whatever the state of charge is when e-Save is selected. It will still use it but it will work to replenish to that state when and where possible. When in e-Save plus Battery Charge, the vehicle will again still use the battery for propulsion but it will work harder to charge the battery as well. Unlike Battery Save where it will only maintain a set state of charge, it will continue to charge the battery until it is full. From an overall efficiency perspective, this mode is the least efficient due to the added work load to the gas engine. When the 2 motor-generators are charging, they place an additional mechanical load on the gas engine on top of rolling the vehicle down the road.
I have so much respect for the decisions the vehicle has been programmed to make. What we have to understand is that there is a spectrum upon which a hybrid system can operate. At one end of that spectrum is performance and at the other end is efficiency. Jeep has attempted to maintain both performance and efficiency in the Wrangler 4XE and that is no small task with a vehicle that weighs 5,000 pounds, is trail rated and has the drag coefficient of a dump truck. But from what I can see, they have done it very well.
I would appreciate any feedback on this analysis. If my graphic is miscommunications something, please let me know so it can be made better. I wanted to create something to help others understand what the vehicle is doing in the various modes. It's a concept that I struggle to communicate since I really lack the true vocabulary and expertise to explain well.
One primary thing to understand is that the Wrangler 4XE is always a hybrid. I'll say it again: The Wrangler 4XE is always a hybrid. It is always working to maximize efficiency while maintaining power.
In hybrid mode when the battery is charged, the vehicle places a high priority on operating in all electric but will add the gas engine for added power when there is a demand. If the driver pushes the accelerator pedal just a little bit more than "normal" when leaving a stop sign, the gas engine will kick on to respond to driver input.
In Hybrid Mode when the battery is depleted to the "<1%" point the vehicle becomes more like a non-plug-in hybrid. It's primary source of propulsion is the gas engine but it uses the electric motors when possible. It maintains a state of charge around 15% that is hidden from view by the indicator on the dash. The vehicle will recapture energy when decelerating or going down hills via regeneration. Even with Max Regen turned off, the vehicle still regenerates when possible. It will also lightly charge via either the eTorque motor/generator or the Traction motor/generator in the hybrid transmission.
In Electric Mode, the vehicle places a high priority on operating on electric only but will turn on the gas engine when there is a power demand. Remember, it is always a hybrid. As such, Jeep has balanced efficiency and performance. While the gas engine will not kick on under the same kind of demand rate as when in Hybrid mode, the driver can still get the gas engine to kick on if they place a high enough demand on the system.
The e-Save mode is possibly the most misunderstood mode of the vehicle. Let me restate the phrase that the Wrangler 4XE is always a hybrid before I go on. In e-Save mode, the operator has a choice between Battery Save and Battery Charge. With battery save mode, we might believe that it places the Wrangler 4XE is "Gas Mode" and the battery just sits there. By observing the power flow screen in the Uconnect, we can see that this isn't the case. The battery is still made available for hybrid operation but it's application is lessened. Much like how the vehicle maintains the battery at 15% in the background when the SOC indicator hits <1%, the vehicle will maintain the battery at whatever the state of charge is when e-Save is selected. It will still use it but it will work to replenish to that state when and where possible. When in e-Save plus Battery Charge, the vehicle will again still use the battery for propulsion but it will work harder to charge the battery as well. Unlike Battery Save where it will only maintain a set state of charge, it will continue to charge the battery until it is full. From an overall efficiency perspective, this mode is the least efficient due to the added work load to the gas engine. When the 2 motor-generators are charging, they place an additional mechanical load on the gas engine on top of rolling the vehicle down the road.
I have so much respect for the decisions the vehicle has been programmed to make. What we have to understand is that there is a spectrum upon which a hybrid system can operate. At one end of that spectrum is performance and at the other end is efficiency. Jeep has attempted to maintain both performance and efficiency in the Wrangler 4XE and that is no small task with a vehicle that weighs 5,000 pounds, is trail rated and has the drag coefficient of a dump truck. But from what I can see, they have done it very well.
I would appreciate any feedback on this analysis. If my graphic is miscommunications something, please let me know so it can be made better. I wanted to create something to help others understand what the vehicle is doing in the various modes. It's a concept that I struggle to communicate since I really lack the true vocabulary and expertise to explain well.
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