8 replies to this topic

[ScottB]

My 2017 Energi did something unexpected on my drive home today. I fully charged the car today at work, drove about 1 mile on a slow road, mostly flat with some down hill. I was in EV now mode and the car was driving fine on the  HVB. I then got on a 1/4 mile down hill stretch of road and I put the car in low and was regen'ing the battery. About half way down the hill, the engine turned on very roughly and it kicked me out of EV now mode. The orange pop up that says the engine is on came up on the left display. I could not shut the engine off and had to drive about 1/2 a mile before it would come out of Auto mode with engine running and go back into EV mode.  Seems weird that I couldn't use the battery for a while, but maybe I hit max charge on the down hill and the computer was protecting the battery from over charging by the regen.  Maybe I hit max battery temp and it wouldn't allow me to draw current until it cooled back down some???

 

Anyone have this happen to them???

[rbort]

Yes.

 

The battery was 100% full and you can't regen any more so the engine starts up to slow you down as you're requesting L gear deceleration.

 

In order to not have this happen, use the brake pedal instead of L when the car is at or near 100% charge level.  This way the car is smart enough to shut off regen and use the brake pads without starting the engine.  In the 2013 model the ^ on top of the battery would disappear even though you've got your foot on the brake.  I have not experienced this with the 2017 model as of yet to see if the circles around the battery will stop going around but will do at the end of July in Lehighton, PA when I visit my friend.  He lives on top of a mountain and coming down to town the battery is 100% full and you have to use brakes not L or hill assist.

 

The interesting part of being there is figuring our which streets to take down the grid of streets to downtown that will allow me to arrive there with 100% charge level.  In other words its possible to go straight down but then you have to come back up slightly to get to the diner.  But if you zig zag down several streets you can get to the diner and use 0.0 kwh staying at 100%  

 

-=>Raja.

Edited by rbort, 28 June 2018 - 06:55 PM.

[ScottB]

thx,  that makes sense and I will use the brakes when the battery is close to full charge.

[fotomoto]

I can make mine start at the end of the block from my house and on a level road.  Just got to meet certain parameters that the engineers have designed in to protect the battery.  For me, it's a full charge, in L gear, warmer temps (air and battery) and braking just a tad to hard for the stop sign.  If I apply no brake, I can usually avoid the startup or remember not use L till after that stop.

 

The Bolt EV now has a menu setting to allow owners who live on hills to not completely charge the batt so it will have some reserve capacity to absorb the regen on the downhill leaving the house.  Nice.

[Hackster]

I read in the C-Max manual that when the engine start to provide "engine braking" (full battery, cannot regen), it does not use any fuel: 

 Engine_Braking.PNG   77.04KB   0 downloads

 

Essentially, it works like an air pump. If true (I am inclined to believe the manual), engine starting while braking is nothing to worry about.

 

[MaxLB]

I read in the C-Max manual that when the engine start to provide "engine braking" (full battery, cannot regen), it does not use any fuel: 

Engine_Braking.PNG

 

Essentially, it works like an air pump. If true (I am inclined to believe the manual), engine starting while braking is nothing to worry about.

 

this might be true when the engine first kicks on and you are actively slowing, but then the engine has a minimum run time for emissions purposes and even if you come to a complete stop the engine will continue to run for 1-2 minutes (and using gas obviously).

[rbort]

^^^ Correct, if the engine starts it will continue to run and warm up using some gas for warmup.

 

-=>Raja.

[ScottB]

Yep, I can confirm this. My engine came on when going down hill right after a charge. I don't know if it was using gas during the down hill, but it wouldn't shut off for a few minutes. I kept trying to get into EV now mode with no engine and it kept saying "engine on"   (I am not giving you an option here).  Eventually 2-3 mintues it let me go into EV now with no engine.

 

That was the first time the car took control and ignored me. We must be married now.

Edited by ScottB, 19 July 2018 - 05:37 AM.

[rbort]

If you make that mistake the only way is to pull over and power cycle.

 

That, or wait for the warmup that you may have not needed to do anyways.

 

-=>Raja.