Keeping EV battery 40% full?

At this point in time, the Prius (plug-in or standard) is not subject to California smog checks. When I got my 2002 Gen I Prius, I was told that back at that time, they had not figured out how to do an emissions check on a car whose engine RPMs they could not control, since part of the emissions test is to rev the engine to a specified speed and measure the emissions. Apparently over the last decade they haven't bothered to deal with this, and the Prius is still exempt. (cross-fingers)

 

Its very inconvenient to stop the charge just 5% before the timer does, in fact, almost impossible. Since the Toyota engineers have chosen 85% and 20% I'll go with them. They have lots of experience.

 

+1 on both posts.
I had plenty of opportunity to experience this exact phenomenon this winter...It's pretty much a no-win situation;
-Keep it in EV mode and your EV miles get consumed- when the ICE finally needs to start (due to speed, power demand, etc..) - it takes a while to warm up and at the same time it continues to draw down your EV miles.
-On the other hand- if you try to beat the system and put it into HV mode as soon as you leave your driveway to 'save' the EV miles for later- the ICE still consumes EV miles while it's warming up.
There's really no way to beat the system... I've tried every combination- the car wins every time.

 

I've found that if I leave it in EV mode for the 3 miles until I hit the on-ramp, then switchto HV, I experience a brief dip in remaining battery percentage, which mostly comes back once the ICE warms up. I usually manage to regenerate the 2-5 % that does not come back while decelerating on the off-ramp.

 

The Leaf'd batter degrade is mostly in hot climates (AZ TX, CA) and in large part its because of the heat. Many leafs in cooler climates (ad discusse don the mynissianleaf site) , and the only I know of in Colorado, have shown virtually no degrading. And with the Volt's active cooling even volts in AZ and TZ have not shown degrading yet.

While I can understanding you being conservative with a raw battery, having a thermal management system and more intelligent charging system really makes a difference.

Agreed, the EREV design needs only a minmal battery power and since it started at 16kW, even if it looses 60% of its capacity, more than most would consider a "dead battery" , it would still likely have a 10-15 mile EV range.. (and enough to keep the system operating). If the battery is weak it will be okay, but the volt will still throw codes if the battery is dead (or disconnected). Don't know how low it can get and not throw codes. We'll have to wait and see.

 

I have an almost identical beginning of trip situation- I have a flat 30mph drive for the first 2.5mi- then I have a curved clover leaf on ramp that's uphill and an accelerating merge lane. That measly .2 mile uphill 270deg while accelerating from 0 to 55mph ramp drains off a full 1 EV mile. If I switch to HV mode just before hitting the ramp- it still burns off 1 EV mile... and gasoline mpg tanks while the ICE is warming up. Basically- it's pretty much the worst imaginable situation for a cold PIP.... uphill climb while turning and accelerating from 0-55 in .2 miles.

 

Um, the existence of the City/Hold mode in the Ampera has been known since at least October 2010 or two months before the first US Volt customer delivery and about 1.5 years before the first production Prius Plugin was delivered. GM has stated or implied that this mode was not initially available in the US market due to regulatory (EPA etc.) rule concerns.

 

Ah, my on ramp and off ramp are both straight, and are on a gentle decline.

 

We knew it was a executive decision, not any type of technical limitation. Unfortunately, enthusiasts at the time saw it as a "too much like Prius" feature, making the decision easy whether there was a regulatory rule or not. No one ever sighted anything from EPA or CARB that would actually justify concern. The EV push was quite intense back then. It's nice to have moved beyond that.

 

Fortunately, what we imagined as a nasty circumstance for a cold engine start scenario (which sadly was spread as greenwash FUD rather heavily) never actually materialized. The battery-pack is able to provide the needed burst of power for the motor to prevent the engine from having to race.

 

I cannot recall a single post here or at gm-volt.com suggesting not giving the US hold mode was because it was "too much like a prius".. In fact that comment would not make much since at the time the plug in prius was not out and hold was not a blended mode use, just saving battery until later. Can you provide a citation to multiple "enthusiasts" or are you just making up stuff again?

We enthusiast all knew it was regulatory issues, e.g. there are posts form 2010 at GM volt
GE to Buy 12,000 Chevy Volts, Cruze Eco Gets 42 MPG Highway Rating, and Opel Ampera Priced

GM Investing $162 Million to Increase Production of Chevy Volt’s 4-Cylinder Engine

and there were posts, in fact I even here on Priuschat about the likely reasons..
OPEL Ampera Better then CHEVY Volt? according to a american? | PriusChat

 

I would try switching to HV about 30 sec before hitting the 270deg clover leaf. But it depends on if you have to sit at a stop light just before that or not. I have a similar situation (no my daily commute) and I switch to HV as soon as I know I won't be sitting at a stop light.

Mike

 

It would seem it's to be expected the mpg would tank when the ice fires up, but that seems the best scenario for efficiency?

If the ice has to run, might as well let it do several jobs at once and get it over with....
1. Heat the engine
2. Recharge the battery
3. Provide the needed extra power for the serious load of a hill or the higher speeds of moving to the freeway or open road.

Once # 1 & 2 are met the mpg goes back up.



Alan.. Sent with Tapatalk 2

 

Question:

Rebound wrote:

In HV mode, the car uses a separate set of battery cells and operates just as a normal Prius does​

Does this mean when going down a long hill in HV mode, the charging one sees is charging a different set of batteries? But the mileage-left-in-EV number rises. So if Rebound is right, that miles-left-in-EV number is the sum of storage from two sets of batteries?

​

​

 

Nope just one battery. There were to in the early prototypes but the production model uses just one.

 

computers compartmentalize the amount of charge dedicated to ev and hv. physically, it's one large battery made up of many small cells.

 

Thanks, guys, for the response.....

Questions seem endless on the car: I start by going down a 2-mile hill. Weather is cool. At some point near the bottom the ICE kicks on. It seems to want to stay on, even though the driving is still slow and flat. At a light I turn the car off. Then on again. That gets me back into EV mode. Since total trip is, say, 7 miles, the ideal would be stay in EV throughout... It appears this has something to do with warming the engine up, and overall I suppose the consequences are small... still....

Of course the off/on is by no means a solution... I guess it will take all kinds of experimentation. On 2005 Prius using B would always turn the ICE off. Not so for 2013.

 

The ICE will start if the EV battery is "too full", so going down hill will a full charge can do that. You can try to use N or try to waste some power before that, or not fully charge.

Once the car starts it will continue to run (even if stopped) until the engine is fully warm. Should be a min or so.