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Outlander B3-5 Engine Spin-Up Protocol - Mike Mas

467 Views 11 Replies 3 Participants Last post by  LowOnCash
Hey Guys - I just got back from a test ride of my 23 Outlander this morning to evaluate what happens when we select higher than B2 mode while in EV mode which causes the engine to start. (Depending on HV battery SOC)

As the car travels in EV mode in “D” (drive) the processor defaults regen level to a B2 setting.

As we move “B” mode to either 3, 4, or 5, the gas engine will immediately start and begin a warm-up sequence running at 1500 rpm raising temperature to roughly 100 degrees and to circulate oil thru the engine. Once the engine warms, it then decreases speed to around 1300 rpm in a readiness state.

During the mode change, the main processor calls up a protocol allowing the drive motors two continue to generate regen power to slow the car, however instead of using the regen to charge the battery, it instead must dissipate the regen energy in another form.

Therefore, rather than charge the battery, current is instead diverted to the engine starter / generator motor which I nick-named “High Speed Spin-Up Sequence”

Therefore, as the accelerator is let off, the regen power created by the drive motors is sent to the engine starter motor, which then accelerates the engine from 1300 rpm high-idle, to well over 3000 rpm, depending on the cars speed. The higher the speed the faster the engine is turned to dissipate regen energy. I witnessed 4000+ rpm at 65 mph.

Considering this is the state in higher B Modes, there is little to no regen advantages using higher than B2 while in EV mode. The Outlander is equipped with large disks and calipers to easily handle slowing the car during high SOC.

I included some images below captured at the OBD port. The first image shows the engine in a warm up state running at 1500 rpm to reach around 100 degrees.

The second image shows the engine warmed in a B mode “ready state” and lowered to 1300 rpm waiting for regen or speed-up.

The third image shows after releasing the accelerator at 45 mph, the starter motor has now spun the engine to over 3000 rpm to dissipate regen energy.

The next two images show the regen levels from the drive motors as the accelerator is let up at the speed of 45 mph. I noted that regardless if the B mode was in 3-4 or 5 regen level did not change and remained constant.

Regards - Mike


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Thanks for the reply - Regen at full charge still goes to the battery. Keep in mind, when we fully charge our HV battery in reference to the dash gauge of 100%, the battery only has an 80-90% SOC. These high / low buffers preserve the HV lithium batteries health and prolong capacity. Manufactures employ charge buffer in the BMS at the top and at the bottom of the battery, so it's never fully charged or fully discharged.

I know for a fact when the dash gauge shows empty or 0 miles, my OBD reports the battery is still at 24% charge level. This is why you can keep driving at "0" miles for a short way. Once the battery reaches 20%, it starts and warms the gas engine. Once the engine reaches 100+ degrees the generator takes over to power the car hybrid mode.

The generator then maintains a 20+% charge using both regen and the gas engine. As you use power from the battery, the generator immediately replaces what was used to maintain this 20% charge. I don't have the figures on this computer but there is a number of protocols and dash warnings at lower percentages to further protect the battery.

Regards - Mike
Mike can you show the OBD battery SOC % when the gauge shows full and empty? Just trying to determine the actual battery capacity. If I'm putting in 19 kWh when I charge and you are saying empty is 24% and full is 80% then we have much bigger batteries then we think.
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