Charging (In)Efficiency

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They didn't require a photo of the installation, just copies of the receipts for the charger and electrical work, and proof that I owned the vehicle. Like I'm going to spend the money for installation, and then use the charger at a remote location with a different utility.
 
I would consider contacting an attorney to send a letter of intent … seems like they are just avoiding your rebate. Ridiculous.

revorg said:
They didn't require a photo of the installation, just copies of the receipts for the charger and electrical work, and proof that I owned the vehicle. Like I'm going to spend the money for installation, and then use the charger at a remote location with a different utility.
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I would think if the EVSE is hard-wired, it would be considered permanent. Temporary if plug-in.

In a lot of cases, rebates are handled by a third party who has in interest in denying as many claims as possible for technicalities. You might be able to get it reviewed by another level or by someone else at the utility directly. Good luck! Never accept "no" from the first couple of people you talk to.

Rob
 
You're probably right about any and all reasons to deny. As far as contacting an attorney, Shakespeare was correct - first, let's kill all the lawyers. The outlet is hard-wired on the side of the house. I chose a plug-in because I didn't want to have to build a weather-proof case. Installing it in my garage would have meant installing an underground connection to my stand-alone garage (which is really more of a storage shed). I will try the "let me speak to your manager" routine, but the rebate won't cover all of the costs. Just between you and me, it was worth the expense just for the faster charging.
 
revorg said:
I just received notice that I was denied the rebate offered by my utility. Why? The charger I installed was not "permanent". Fap!
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Did they perform an on-site inspection or did you tell them your EVSE plugs into an outlet?
 
There was, of course, a form to fill out. No inspection, no questions about hard-wired or plug-in. To tell the truth, I was surprised by how quickly they responded. I say they, but the email did not actually come from the utility. I did momentarily wonder if it was spam, but it didn't ask for any reply. I have a hard time believing that they were familiar with the charger I bought - there must be a bazillion chargers for sale.
 
I have a smart charger and can measure electricity used. The last charging session provided 22.78 kwhr. The mini App said 23 kwhr. I noticed no excess power use. Make sure you don’t have on “precondition for departure” as that will obviously use extra electricity. The charging from 90-100% should not cost more, it merely can’t charge as fast which is mostly noticed in DC fast chargers. Most paid chargers only charge you for electricity delivered, not time charging. Energy cannot just disappear. If it was only converting 60% to the battery, then the remainder would be dissipated as heat, which does not seem possible (but I am no electrician). Smart level 2 chargers are nice because you can get cheap electricity at night and have the car wait to charge until then.
 
Greencarguy said:
I have a smart charger and can measure electricity used. The last charging session provided 22.78 kwhr. The mini App said 23 kwhr. I noticed no excess power use. Make sure you don’t have on “precondition for departure” as that will obviously use extra electricity. The charging from 90-100% should not cost more, it merely can’t charge as fast which is mostly noticed in DC fast chargers. Most paid chargers only charge you for electricity delivered, not time charging. Energy cannot just disappear. If it was only converting 60% to the battery, then the remainder would be dissipated as heat, which does not seem possible (but I am no electrician). Smart level 2 chargers are nice because you can get cheap electricity at night and have the car wait to charge until then.
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Sadly, it does seem to be dumping all that energy. Lost in conversion. It is not due to preconditioning.

The app numbers correlate well with what I'm measuring coming out of the wall.

It does appear that the last part of charging is considerably less efficient. The one sample in the last week that stopped at 74% is much more efficient. And short charges to 100% are worse than longer charges.

upload_2022-1-26_18-24-11.webp
 
With the change of the month and my new tracking of my charging, it looks like the MINI app doesn't list the charge session that runs over night at the end of the month!

My January page shows the charging session for plug in Sunday 1/30 and unplugged Monday 1/31.

My February page shows the chargine session for plug in Tuesday 2/1 and unplugged Wednesday 2/2.

But where is my session plugged in Monday 1/31 and unplugged Tuesday 2/1?????? Nowhere that I can find. Same for end of December. I know I drove the car on 1/1 so there should have been a session plugged in one day late in December and unplugged on New Years Day, but there isn't.

Rob
 
I don’t know if this has been discussed already but I wanted to add something else to the charging efficiency discussion…3.6kw vs 7.2kw. I have a Lectron 40amp capable charger. I purposely set my car to the reduced (3.6kw) rate thinking that would be gentler on the battery (less heat/stress) since I’ve got all night to charge it anyway. Looking at this discussion got me thinking about the efficiency difference between the two so I did two test charges on high and concluded the reduced rate is a little more efficient.
%start. %end KW reported. Efficiency
42 100. 22. 76.19
24. 90. 23. 82.93

Some comparable charges previously were:
32. 100. 23. 85.44
41. 100. 20. 85.26
26. 82. 19. 85.18
42. 91. 17. 83.3

Sorry for the poor formatting, I’m on a cell phone at work.


Sent from my iPhone using Inside EVs
 
You will also have to factor in battery temperature when doing a 3.6kW (15A*240V) vs 7.2kW (30A*240V). For colder climates, there may be a slight advantage to charging the car immediately after getting home versus letting the battery cool down. Then again, it still may cost less waiting for off peak rates.
 
"Off peak" rates don't exist everywhere. Puget Sound Energy (at least in my area) only has one rate for the first 600 kwh and another for everything over that.

EDIT to add: our rate is about $0.125 for the over 600 kwh level (and even before the SE, we were always over 600)

Rob
 
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That's true. It's roughly $0.35/kWh for me with no off peak rates. Premium fuel is about $6.8/gal.

If it wasn't for home solar and free charging at work a Cooper S would make more financial sense.
 
For clarification I’m in South Carolina which isn’t very cold, although it did snow the other day. I always charge in my garage with the door closed in the middle of the night.


Sent from my iPhone using Inside EVs
 
teslarati97 said:
That's true. It's roughly $0.35/kWh for me with no off peak rates. Premium fuel is about $6.8/gal.

If it wasn't for home solar and free charging at work a Cooper S would make more financial sense.
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Electric rates for residential here in Ontario is $0.082/kWh (in USD, about $0.06/kWh) almost 1/6 the cost you are paying.

Regular fuel is $1.529/litre (or in USD, about $4.56/gal).

I haven’t checked premium fuel lately but generally, about CDN $0.14/litre more or USD $5.01/gal


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I'm using the factory supplied charge cable. I noticed that it pulls 10A all the way up to fully charged. My expectation was that it would reduce charging current during the last, constant voltage, phase.

I wonder why it behaves this way. This must be a source of inefficiency. I've also noticed that charging efficiency is worse for the top 20% of charging, which supports this thesis.
 
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