Charging cost

There are Level 2 EVSE's, along with connected tech, that will collect and chart a ton of info. If you decide to charge with one of those, I'm pretty sure that option will offer more detail.

 

Yes on the multi-information display, when you cycle through the screens, you should come across the EV Driving ratio screen. This has a Trip A and Trip B. It keeps track of total kWh consumption by the car until reset. Many of us reset only Trip A every time we refill and keep Trip B as the long accumulator. Fair warning though, all trip totals get reset if the 12V battery is unplugged or on occasion by the Service Department . So I keep a spreadsheet with each fill up that records the kWh for each Trip A. Rather easy if you have only 27 fill ups over 3 years.


Unsupervised!

 

Yes, the car keeps records of what it uses, but what is wanted is what it takes from the grid. Charging is not efficient and that has to also be accounted for.

Something like a "Killawatt" (inexpensive and easy to use) for 115V. Not sure if they have one for 230V, though if you know what you're doing you could use two, one on each "phase" of the 230V and a "kitchen plug" in the garage (one phase on each of the duplex receptacles) and a "two 115V" plug into a 230V receptacle. I'm sure there are other options on the market.

 

As said if you never reset one of your EV ratio screens, then you can track the amount of kWh the PiP has been charged.

However, it is more accurate to track how much energy goes onto the EVSE as charging is a lossy conversion. I think we used 115% for Level 1 and 110% for level 2?Someone can correct me.

In other words, on level 1 my PiP recorded a charge of ~3 kWh last night. But my utility charged me ~3.5kWh worth as that's how much was lost in heat. You can feel the plug is warm and hear the battery fans turn on in the trunk.

 

Unless you have an exact amount of electricity that flows into the car you would have to estimate it. As @mmmodem said we use the estimate of 115% or 15% more to account for charging losses at L1 level. We assume L2 is more efficient so that gets knocked down to 10% additional to what the PiP records as consumption.


Unsupervised!

 

I imagine, they would have to do it at the EVSE which would increase its cost. The current PiP EVSE is $1000 for replacement so I'm going to vote they not do that. Hard wired Level 2 EVSE's likely has a monitor of energy consumption. The low tech way is to plug the EVSE into a kill-a-watt device.

 

you even have losses from the electric meter to the circuit breaker, and from there to the outlet.

 

Plug in level 2 EVSEs can have it. Bob Wilson got a JuiceBox for his i3 REx that does this monitoring that can be accessed by internet

post132 here
Why the BMW i3-REx | Page 7 | PriusChat

There are losses along the way for all fuels. We measure from the outlet or pump to stay saneish.

 

definitely ish.

 

I used a Kill-o-Watt on the 120v (US standard voltage) EVSE that came with the PiP and calculated about a 75% charging efficiency. Others have said that 240v charging is about 85% efficient.

Since the battery cooling fan runs while charging, it consumes energy. Cutting the charging time in half by using higher voltage (L2 charging) cuts the fan run time in half, and cuts the charging losses to the fan in half.

Running higher voltage also reduces line losses, which is energy that is lost as heat just traveling down the wire.

There are energy monitors for 240v lines, but they have to be wired into the breaker box and the price is $100 or more. It's good enough to simply apply the multiplier given above to the KWH displayed by the Prius.