Here is the comparative formulas for operating a PiP in all gas vs. all electric

3.2 kWh from the wall is a worst case scenario when using a 120V outlet to charge a fully depleted battery. Keep in mind that the rated capacity of the traction battery is 4.2 kWh. The actual usable capacity of the battery for EV usage is 2.6kWh. SOC of a fully charged battery is 85%. When SOC hits 23% the car switches to HV mode. So approximately 62% of the battery is available for EV mode. 0.62 * 4.2kWh = 2.6 kWh. Charging at L2 rates (240V) is way more efficient, so 2.7 from the wall for an L2 charger isn't unreasonable. The losses at 120V are anywhere from 20 to 30 percent, so 3.2 kWh sounds about right.

 

ChargePoint typically reports a full recharge for me at 240v as having used around 2.8 kWh.

 

For me I think the argument over hybrid versus regular, or plug-in hybrid versus regular hybrid comes down to an emotional response, not a pure economic one. The premium paid for either one (hybrid or plug-in) is not insignificant and shouldn't be ignored. But it should be pointed out that people buy cars all the time with expensive options that don't necessarily save them any money in the long run. A couple of years ago my wife bought a Mini Countryman. It had as an available option a turbo-charged engine. That option was $3500. Just to have a faster engine with slightly worse gas mileage. An available automatic transmission for that same car? An extra $1250. For her, it didn't make much sense to opt for those two options. But some other buyer will obviously want it, otherwise Mini wouldn't offer those options.

 

You may want to fix it. It is 4.4 kWh per Toyota spec.

 

If it recharged SOC from 23% to 85%, that's 2.7 kWh in the battery. 4.4kWh x 0.62.

0.1 kWh is 3.6% charging loss. Too good to be true?

 

Today's report, in basically ideal conditions (low 70's and overcast), it took exactly 2.697 kWh.

 

Ah, I hadn't realised that. Makes sense, here in the UK we're told a ninety minute recharge from 0 to max, and it seems to draw at 1.9kw. That takes a few pence off my charge cost!

 

Probably. The 240V charging losses I measured back in February (How Many kWh in a Full Charge? | Page 4 | PriusChat & How Many kWh in a Full Charge? | Page 5 | PriusChat) were estimated to be between 8% and 12%. I probably should repeat the measurements now that I have had my ScanGauge II updated to the latest firmware and can now get battery pack voltage readings.

 

its been mentioned here many times recently that PiP vs hybrid premium was large in the early days but now ridiculously small after incentives
I don't throw money around needlessly, I had a suburu wagon go 17 years and more recently was driving a '99 Avalon.
For me the decision for me was absolutely financial. I figured with my driving habits I could make back the premium in 3-4 years. And I was wrong - it will take less than 2 years !

 

Yes, but when you say a full charge, you also drove in HV mode and used more than just the EV range, right?

Mike

 

Yes, and my point is that people are using this 3.2 kwh number in formulas relating to pure EV miles driven. It only makes sense to use the recharging of the EV allocated portion of the recharge to account against the EV miles driven. The remainder of the charge (another .2-.3 kwh maybe) are part of the hybrid mode driving...they tend to boost your mpg when using gas.

Mike

 

Using the worse case scenario of 3.2 kWh from a 120V wall socket sets the ceiling for electricity consumption for recharging purposes. That's the worse you'll do (or the most you'll pay for a charge). If you are able to use L2 sources for recharging, your costs from the wall go down as a result and you get a marginal improvement in your payback period.

 

I also drove in HV mode; however, the SOC when I got to the parking spot was 23.5%. I had run out of EV just moments earlier. That's what happens when you commute with PHV long enough. You use HV in the middle of the trip more effectively and can guess quite well how much EV to save for the end.

Your question does bring up a good point though. Sometimes I do indeed use some HV and replenish it with the plug. There's a long stretch of flat road on the way home from running errands. If I don't have electricity for EV left, I end up driving with the engine off in HV instead (Stealth mode). It's a win-win... but difficult to account for in terms of kWh.

 

It looks like your avg speed was 29 mph. If I drove that slow, I could get 62 mpg on my standard Prius with no problem. Energy and matter could not be destroyed nor created. Therefore, if your battery is depleted and continue to drive, all of the energy will be coming from gas. At that point, the only advantage the PiP has over the standard is the bigger battery to capture regen energy. So if you were going down a very long hill, you will definitely be able to capture more energy than a standard Prius and potentially get better mpg. On flat land, the PiP with a depleted battery has no advantage in mpg.

 

The distance is 29 and the time is 1 hour, so the avg speed is 29 mph. I can get 76 mpg on local roads

 

That's not what the value represents. It includes the time the vehicle is not in motion. So whenever you stop and the system is on, that counts against the speed... giving a false impression of actual travel, but a very accurate measure of overall. That average takes everything into account.

I beg to differ. It's pretty darn flat around here. Sunday's no-plugging-in results certainly outshined what my 2010 would have delivered under the same circumstances...

 

I don't drive a steady pace, I pulse and glide. I either glide in neutral or use some EV energy. My local road is a mixture of 25 and 35 mph speed limit with lights and stop signs. The road is relatively flat. I don't get 76 mpg all the time because it really depends on the traffic. But getting 62 mpg going slow is not a problem. In many longer trips that I took on freeways, I get between 57 to 58 and I even had my A/C on.