EV Strategy Question

use the EV miles till I get on the freeway then save the EV miles for the rush hour drive home?


Try both ways, but I think your second choice will work better.
Enjoy your new car!

 

welcome to priuschat! no problem leaving the battery partially charged.all the best!

 

Agreed. But on the way home use the EV miles for flat or downhill not any significant uphill or high speeds.

 

Stop-and-go: I wish the PIP had an auto-creep option on its radar cruise system.

 

Most of the time, it is better to save the EV for the return trip home. There are no issues with leaving a partially charged battery for half a day.
1. I get up to 20 EV miles creeping home in rush hour traffic. Sad, I know. Using up EV on the freeway in the morning, it would be gone in about 10 miles.
2. It's cold in the morning. Heat requires running the engine. Saving EV for the afternoon gives you heat in the morning.
3. It's usually warmer in the afternoons. The battery performs better in warmer temperatures (up to a point). AC is electric so you can have AC on hot afternoons without the ICE coming on.

 

I would say use EV for slower or stop and go type of traffic. HV for long highway drives.

Try different strategies. The goal is to increase efficiency of both fuels in EV and HV miles.

 

I have a 50 mile commute one way and also on the way home I have EV miles since I can charge at work. However I try to save my EV miles for about 30 miles into the commute for when traffic starts. However I notice that my EV miles still decrease even thought I have changed it to HV mode.

Is there a way to get Prius to truly not use any EV battery until I need it?

Thanks.

 

Basically no. If you're running in EV and start the ICE for the first time on that trip the car uses some EV so the ICE doesn't have to work too hard while warming up. That is usually about 1 mile of EV unless you are going up a steep hill at the time you first switch to HV then it can/will be more. Also if the SOC is greater than 75% the car will use EV miles until the SOC is below 75%, that could represent more than 1 EV mile. In general, when the ICE is up to temperature (130 degrees) the EV miles will stay within 1 EV mile of when you switch then operate in the normal HV manner up and down that 1 EV mile range.

 

This is an important point that I don't think Toyota has properly clarified: The PiP is essentially a factory-modded Prius hybrid. Toyota did not intend for it to be an EV (with lame EV range and limited maximum speed in EV mode); it's just a Prius hybrid with a bigger traction battery that can optionally be recharged by plugging it in, providing more use of electric mode than the standard Prius. Toyota has made it real clear that they are not interested in BEVs.

OTOH, the Volt is designed to be an EV with a standard, not-particularly-interesting ICE dropped in to enhance its range. (No criticism intended; just different design objectives.)

 

It depends on your usage. Almost all of our trips are short, many within the 12 mile EV range. A couple of times a month we go on longer trips and have found the PiP provides somewhat better mileage than the standard Prius, some because of the 12 miles of EV but a good amount due to the excellent regeneration capability. On trips where I got about 55 mpg with the standard Prius Three I getting more like 66 mpg with the PiP. Including all trips my overall use is 58% EV. While not necessarily the best choice for all drivers it seems like the PiP is a perfect match for my purpose.

 

I think it was done for a reason. When SOC is higher than 75%, battery regen brake cannot take max power required to HV operation.

 

I don't know what you mean. However, it is quite easy to use regen to charge to 85% SOC and then use it in EV operation. Its just if you go back into HV with a full charge (85%) the car will use up the EV to get it down to 75% SOC.

 

This is also hard to understand. At 85% SOC in HV does the car use charge in a different way then it does at 75% SOC?

It makes sense to me that regen wouldn't max out above 75% to help keep the packs cell modules in balance with less than max regen above 75%
Similar to charging when charge rate drops for the last few minutes.
My charge rate when plugged in drops when the charge timer gauge shows 5 or 6 ie: 30 to 36 minutes left to complete the charge, but it never continues charging for more then 10 or 15 minutes from that point. At least so far in the warm weather anyways.

Regarding leaving the SOC at 80% all day, I'd think that is fine, imo anyways and I doubt that it would make a noticeable difference what SOC you leave the pack at for a few hours, under normal conditions. Extreme high or low temps, I think there will be noticeable differences in pack stats for those who watch real close.

The SOC may change a small, possibly measurable amount, over several days, that the ev distance gauge will not show initially when starting the trip.
I doubt anyone could see those kinds of differences in SOC using the factory gauges..

 

Are there any hard statistics here? The OP's scenario was a 50 mile (interrupted) trip, starting from 85% SOC, where freeway speeds occurs after 2 miles, but then stop and go after 25 miles. Strategy 1 is to use EV from the start; strategy 2 is to switch out of EV and turn it on at mile 25.

Do we know how much gas is used in strategy 1? (Presumably between 1 and 2 gallons?) Anyone willing to offer a percentage difference estimate for strategy 2?

 

I think without a real detailed description of of the commute both ways, we would be hard pressed to find any conclusive results from which is the better strategy for the OP, much less any other commute sceneario which may be slightly or completely different, even if those differences are not noticeable to the driver yet.
Differences such as slight, over all incline and declines that are only noticeable by watching the MPG and SOC of a trip in both directions at the same speed and traffic conditions.
as always, YMMV

 

That is pretty much what I was trying to get at -- that the differences aren't conclusive and perhaps aren't significant. It is, after all, a nontrivial but pretty small traction battery.

"Just drive it."

Before I got my car, I recall seeing a Prius parked at a train station here near Frederick, MD, with a vanity plate YMMV. In the back of my mind, that is one of the reasons that I started thinking more deeply about Prii.

 

I'm trying to follow the strategy some of the others recommended - EV on local roads/traffic and HV while cruising on highways. That way I save some charge for my afternoon commute. Been trying this for a week and I notice in the morning commute (less AC use) I get around 80-90 mpg, and afternoon commute (more AC use) around 70 mpg.

 

What were your mpg numbers before, so you can compare?

 

"use charge in a different way" no it simply uses it to aid the ICE in the normal manner but keeps using it until the SOC is below 75% as this is better for battery life. As near as I can tell going down lots of mountain highways the regen charging is pretty much the same from 75% to 85% as it is from 65% to 75%. So.. for the mountain variable up/downhill highway (I80 in CA) you need to use the last part of the downhill to get that last 10% of charge. If you don't the uphills in HV will quickly reduce the SOC down to 75%.