Another Battery Degradation Thread

That actually makes sense, because the trip to the mall was mostly an uphill climb, therefore the HV power reserve was probably a bit low. Since the computer is designed to optimize fuel economy, it makes sense that it would want to "borrow" some power from the EV reserve rather than burn fuel just to charge the HV partition of the battery. That might explain the missing EV range.

 

by george, i think you've got it! but don't some claim that ev is replenished after ice warm up?

 

I still think when the ICE starts up, it will replenish some EV it uses. But in my personal experience, I've never witnessed this with a full battery. What I mean is, I've never switched to HV on a full-charge. I've only switched to HV when I was down a few miles of EV or only had a few miles of EV remaining (but we have also now heard from a few owners who have witnessed it replenish EV range and then use it up again, so clearly YMMV).

I think whats unique in Greg's case (and in others who have seen this) is switching to HV immediately after starting the car with a full charge (presumably 85% SoC).

 

i switch to ev as soon as i fire it up in some cases. i always lose 3-4 ev miles as the ice warms, and then i'm on flat ground going 35-40 and i would have to floor it for the ice to come on.

 

Yes, and I was hoping to avoid that bone of contention this time. I'm not a hybrid vehicle engineer, but if I were, and my boss were applying pressure to design a hybrid system which delivered the best fuel economy in it's class, I wouldn't want the ICE to be burning much fuel just to charge the hybrid battery. I'd want as much as possible of that to come from regeneration or from plugging-in.

 

Interesting about the ICE utilization. I am wondering if Toyota somehow changed the logic on the ICE engine for the 2014 model. On my first start of the day, the ICE comes on regardless of outside temperature. It does it when it is cool, it does is when it is mild, it does it when it is warm outside and yesterday it did it when it was just plain hot outside. I live on top of a hill and there is nothing more annoying than having the ICE running while going downhill and not be in EV mode. I hit the stop sign and accelerate oh so slowly and the ICE starts driving and my MPGe drops. After that initial run, I can have as many intermediate runs and no ICE as long as I have range. I normally just leave the car in EV/ECO mode. Any thoughts anyone?

 

Climate control set on Auto/On? or off?

 

I don't think we should always associate running the ICE with wasting energy. In order for the hybrid system to function properly, the ICE needs to be able to run whenever it's necessary to maintain the hybrid system. This means it needs to bring the engine up to operating temperature, cool hybrid components and charge the hybrid battery, even though this is minimized as much as possible. Your Prius (and mine) are plug-ins, but that doesn't mean they never burn fuel; it means they burn less fuel than a non plug-in (if you choose to plug it in). Remember that a regular Prius obtains all of it's energy from gasoline.

 

It's not clear just how you start your drive. If you press the power button and the engine fires up, then Tracksyde's question is right on. If you press the power button and are able to pull out of the driveway in EV mode and start down the hill but need to brake to control speed you may be regenerating more than the almost totally full battery can accept, so the engine starts to drain off excess charge in order to not exceed the max allowable state of charge .

 

It starts but doesn't use fuel. So there is always that.

 

I am pretty sure that if the engine is turning for any reason (fueled or not) that it has to first go through the warmup cycle. So even if, for example, it is using compression braking without fuel to slow down going down a hill when the battery is full, that it still has to warm up first.

 

If the battery is full and you apply brakes, the energy has to go somewhere. In most vehicles, it's released as heat; either through the brakes, or by engine-braking. In the case of the Prius, it would make sense to use engine-braking.

 

Start an A/C cycle just before you leave and see if the ICE still comes on. Turn it off when you get to the bottom of the hill. You should be able to get back most of the EV used for the A/C cycle.

 

Does it? I wasn't aware of that. I've never been in a situation where that would happen but if that's the case I could understand the frustration.

 

phil, this is covered in the faq. they have not changed the 2014 logic.

 

More than just a spreadsheet will be available... I was able to film this same drive home from work today, it was even the same temperature. 12.4 miles of EV. 17.4 miles total. 191 MPG for the trip.

The video footage looks great. The camera photos look great. The data captured from the Torque app looks great.

I can't wait to assemble it all to share here!

 

I bet it looks great!!!!!

 

Looking forward to the show.

By the way, your 5 miles in hybrid mode were ~ 55 mpg.

 

as we get deeper into summer, i'm becoming more and more convinced that my range is the same as new. but i won't swear to it until i hit the far side of the bell curve.

 

Mines seems to be about the same if not better!
Or the car is training me better!
more than likley the later.