How many watts does it take for a full charge in a 2013 PIP?

My results: SOC from 25% to 85% (full operating range) 2.93 kWh out of the wall at 120 volts using a Kill-a-watt meter. Cost at my weekend or weekday nighttime rate 14 cents, at my weekday daytime rate 30 cents.

 

Did you start the charge with 0 EV miles and 6 bars on the HV battery icon?

 

The OC is always good for a laugh - with them, of course.

 

That is pretty much the starting point however, those have little to do with an accurate measure of the state of charge. If you push it you can get slightly below 25% SOC but not above 85.4%. I have seen 23% a few times but did not have an opportunity to measure the charge kWh. That would require closer to 3.0 kWh for a full charge. I guess if you want to consider a maximum possible full charge it would be something slightly over 3.0 kWh, but not much over. Typical is much more likely to be slightly less that the 2.93 kWh. All pretty much the same amount for a "full" charge.

 

If I am not mistaken, others are consistently reporting 3.1-3.2 kWh from the wall using 120V, maybe you need to calibrate your meter?
2.93 kWh from wall to get 2.73 kWh net to the battery calculates to less than 7% charging losses which is suspiciously low!

 

Sorry, but I do not agree, zero EV miles together with 6 bars on the icon is a pretty accurate indication of SOC as the car's meter measures it - 23%.

 

2.93 kWh divided by 0.6 (for 60% SOC change) gives an apparent "full" charge battery size of 4.88 kWh. The actual size is 4.4 kWh so the efficiency is 4.4/4.88 = 90% or 10% in losses. Here are the series of measurements I made.

 

Ok, I agree, that's "pretty" accurate which is a good way to characterize the whole subject

 

Strange calculation...
Also, you stated in previous post that zero EV miles is "pretty much the staring point" of all your charge measurements - cannot see that in the table (except maybe for the 13.4 miles line).

 

efficiency is not a factor here. The relevant variables are:

Nominal_capacity * Fraction_of_battery_used = Available_capacity_from_full_charge

 

Those are all EV-only trips. Start with full charge (SOC 85%), go on trip, measure kWh for full recharge.

 

I was responding to a claim that my losses for charging were 7%. They are more like 10%.

The "Full" Charge column is the apparent size of the entire battery if there were no losses. Since the actual battery is 4.4 kWh we can calculate the apparent efficiency of the charging system.

Here's an interesting question? What is the actual battery capacity in your car? Is the battery new or a year old? Are there manufacturing variations? How about 4.36 kWh to 4.44 kWh which is plus-minus 0.45%. Is a new battery really that tightly controlled? Perhaps its 4.4 to 4.6 kWh, that's plus-minus 2.2% always above the 4.4 spec. Is that a reasonable manufacturing tolerance?

 

These are partial recharges. By "full charge" you probably mean 'recharge to full' but it is still a partial charge as I understand it.
Maybe you can try this:
start the charge with 0 EV miles, make a full charge and measure kWh from wall. As we know that in one full charge (from zero EV) the battery gets 2.73 kWh you can calculate charging losses.

 

Doing a 0 EV to full charge would be the most accurate which is where I got the 2.93 kWh from the wall. However, the shorter trips (on the average) tend to support similar results. Then there's "What actual size is the battery?" as discussed in another posting.

 

Here is another interesting question: How accurate is your instrument measuring SOC of the battery? +/-5% is that reasonable manufacturing tolerance?

 

Good point! Although it always reads 85.3% plus-minus 0.3% at "full" charge. Of course, that's what's reported to the ScanGage and we know how accurate the Prius reports are

So what is it we are discussing here? Perhaps its all in the accuracy noise level. A "full operating charge" is around 3 kWh. Gets you somewhere between 10 and 14 miles depending on lots of variables. End of discussion.

 

That's precision not accuracy!
The known fact is that charging losses when charging by 120V source are 15 to 20%, 15% is being optimistic, 10% or 7% are suspicious.

 

I guess my kill-a-watt meter didn't get the message. I don't have a way to check it. It does make my mpg-e measurements look better even if its not true

pre·ci·sion
priˈsiZHən/
noun

1. 1.​
   the quality, condition, or fact of being exact and accurate.
   
   "the deal was planned and executed with military precision"
   synonyms: exactness, exactitude, accuracy, correctness, preciseness;

 

Precision in scientific measurements is (in plain words) how the reading differ from the average reading.
Accuracy is how the reading differs from the true value.

 

They are more like 15%, but are irrelevant to the question.