Setting Charge Times

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RAV4Elly

Active member
Joined
Apr 16, 2013
Messages
34
I just received my 40 AMP charger from Amazon and it is now installed. The size of the cable and the soundit makesis pretty impressive. Myfirst thought was I only want to charge when the Edison rates are at the lowest rate, which I have read is after midnight. I could only find in the ev section of the computer the set departure time with the three choices of charge, pre climate and both. If Iwant it to charge after midnightonly do I just set this schedule to 7 AM daily departure? Will it charge during the time just before 7?
 
RAV4Elly said:
If Iwant it to charge after midnightonly do I just set this schedule to 7 AM daily departure? Will it charge during the time just before 7?
Yes, that's the idea... But prepare to be disappointed. Also, you don't automatically get cheaper rates with SCE by charging after midnight, make sure you've called them up and switched to time-of-use metering.
 
Fooljoe beat me to it, but you do need to change your rate plan to a time-of-use (TOU) rate plan if you want cheaper charging at night. Alternatively a second meter installed just for charging the EV is also an option but has a greater upfront cost. The SCE TOU plan I am on has super off peak usage between 12am-6am. Keep in mind that changing to a whole house TOU metering (i.e. single meter for the whole house) your electricity costs during peak times will increase, so if you use a lot of power during the day (10am - 6pm) especially during the summer you electricity costs could increase, but for us even without the extra electricity used by the EV the TOU plan ends up being cheaper.

Also as was pointed out, some people have had difficulty with the delayed charge function of the RAV4. With my 40A EVSE the only issue I have had was that it overestimated the charging time by 66%. Despite the overestimation of the time, with my departure time set at 6 am it still starts and finished charging within the super off peak hours if I have greater than a 1/4 of a charge left. I think setting a 7 am departure time should work even better.
 
Thanks for the responses. I just finished reading the 17 pages of discussion related to this.
 
I set a 7am departure, and it almost always hits the midnight to 5am window for Super Off Peak that San Diego Gas & Electric uses (I also have a dedicated EV sub-meter from SDG&E).

Your utility will have different times, rules, rates, etc. Please contact your utility for details.

The above is based on 40 amp charging. Slower chargers will not save money if they charge outside the Time Of Use (TOU) window.
 
I don't think some of you realize that that a fully completed recharge occurs in TWO sequential but separate periods of time. The first and longest period of charging, does the bulk of the job and takes several hours. This is followed by a "sleep period" of ~2 hours, when no charging occurs. Then, there is a much shorter, ~30 minutes, "cell balancing" charge that usually (always?) occurs to complete the entire recharge cycle. The latter, is also done at a substantially lower charging rate; <10% compared to the bulk charging rate.

I don't know how important it is to allow sufficient time for the cell balancing charge, or if it is of any importance to be done each time, or only sometimes, but I do suspect that this "extra" charging time is partially to blame for messing up the expected start time for a regularly scheduled bulk charge. This, like many other observations here, is just another theory.

Nevertheless, if I set the center console timer to complete by 7am, this very well may cause the charge to initiate before midnight, especially if the battery is fairly low on charge to begin with. However, if I set the timer to complete by 10am, there is much better assurance that the charge will initiate AFTER midnight and still very likely complete well before 7am. Then, around 9:40am, the cell balancing charge will initiate and usually completed a little after 10am. I've timed it, and it seems to take almost exactly 27 minutes!

Fwiw, I have actually recorded this entire sequence of events while charging my 2012 RAV4 EV many times, so I know this is how it works. But, I don't think most people know this unless they have a way to constantly monitor their EVSE L2 charging stations to know when it is under load and when it is not, and by how much. Btw, my Leviton EVSE that I installed late last year, is rated for 32A, 7.7kW. This is still quite adequate to complete an overnight charge within the TOU lower rate "off peak" period.

I do my setup for a "weekly" timer charge Saturday evening, preferably after 9am, and schedule completion Sunday morning at 10am. This is really a FAILSAFE way to charge so that I avoid charging any time other than off-peak. Off peak has extended hours on weekends. This was my routine during the Winter rate schedule. Summer rates will probably require a slightly later plug-in setup time in order for off-peak charging to remain in-effect. Fortunately, I typically drive my RAV4 EV less than 100 miles per week, so this regime is entirely doable for me, i.e. scheduling a charge only once per week on Sundays.
 
My assistant spoke to Edison and I am billed for electricity based on how much I use period not when I use it. I am therefore plugging in and charging. Therefore it will be plugged in and charging from 6 PM to 7 AM. I am assuming my car will figure out the best way to completely charge the batteries.
 
Dsinned said:
I don't think some of you realize that that a fully completed recharge occurs in TWO sequential but separate periods of time. The first and longest period of charging, does the bulk of the job and takes several hours. This is followed by a "sleep period" of ~2 hours, when no charging occurs. Then, there is a much shorter, ~30 minutes, "cell balancing" charge that usually (always?( occurs to complete the entire recharge cycle. The latter, is also done at a substantially lower charging rate; <10% compared to the bulk charging rate.

I don't know how important it is to allow sufficient time for the cell balancing charge, or if it is of any importance to be done each time, or only sometimes, but I do suspect that this "extra" charging time is partially to blame for messing up the expected start time for a regularly scheduled bulk charge. This, like many other observations here, is just another theory.

Nevertheless, if I set the center console timer to complete by 7am, this very well may cause the charge to initiate before midnight, especially if the battery is fairly low on charge to begin with. However, if I set the timer to complete by 10am, there is much better assurance that the charge will initiate AFTER midnight and still very likely complete well before 7am. Then, around 9:40am, the cell balancing charge will initiate and usually completed a little after 10am. I've timed it, and it seems to take almost exactly 27 minutes!

Fwiw, I have actually recorded this entire sequence of events while charging my 2012 RAV4 EV many times, so I know this is how it works. But, I don't think most people know this unless they have a way to constantly monitor their EVSE L2 charging stations to know when it is under load and when it is not, and by how much. Btw, my is a Leviton 32A, 7.7kW unit that I installed late last year.

I do my setup for a "weekly" timer charge Saturday evening, preferably after 9am, and schedule completion Sunday morning at 10am. This is really a FAILSAFE way to charge so that I avoid charging any time other than off-peak. This was my routine during the Winter rate schedule. Summer rates will probably require a slightly later plug-in setup time in order for off-peak charging to remain in-effect. Fortunately, I typically drive my RAV4 EV less than 100 miles per week, so this regime is entirely doable for me, i.e. scheduling a charge only once per week on Sundays.
Dennis... so to get this straight you are saying when Entune says that the charge cycle is complete that it isn't really finished? When I plug in and start a charge cycle immediately it tells me on the iphone that it will finish say... in 3.5 hours. It often finishes sooner than what it first gives as a time to finish say... in 3 hours and 10 min instead of the actual 3.5 hours. At the end of the cycle it sends me an email telling me the charge is completed and my phone gives me the same completed message. The ClipperCreek is off and I unplug and go. Should I leave connected for another 2 hours or so to let it do the cell balance cycle? Thanks for your help!
 
RAV4Elly said:
My assistant spoke to Edison and I am billed for electricity based on how much I use period not when I use it. I am therefore plugging in and charging. Therefore it will be plugged in and charging from 6 PM to 7 AM. I am assuming my car will figure out the best way to completely charge the batteries.
Southern California Edison has EV rate plans just like PG&E does. The regular residential rates are 13 cents to 31 cents/kWh in 4 tiers, similar to PG&E. Their combined home and EV rate varies from 9 cents to 47 cents/kWh in the summer and 10 cents to 35 cents/kWh in the Winter. This plan only has two tiers, up to 130% of baseline and over 130%. Edison's peak window is longer and much earlier in the day (10am-6pm) than PG&E (2pm-9pm). Having the Peak window earlier in the day is very advantageous for solar net energy metering.

After you get your first bill, you may be motivated to call Edison yourself and find out what they expect your bill to be on the TOU-D-TEV rate plan if you charged after midnight.
 
My assistant asked them and they stated the 4 step plan is cheaper. I just received my 40 amp charger 2 days ago so I will check out the bill for May. Thanks for the info.
 
Last night was my the second night I charged the TesRav with the Leviton 40 Amp charger. This morning I noticed that my indicated range was 100 miles. It was always 92 on a standard charge. Does the 40 AMP charger increase the range?
 
No. The estimated range is based on your latest driving efficiency. If you were driving with a lead foot (very inefficient), the estimated range would read low. If you hypermile (drive extremely efficient), your estimated range will increase. I typically drive at an efficiency of 3.3 miles/KWHr and at the normal 80% charge I get an estimated range of 115 to 120 miles. I've had extended charge estimated ranges of over 144 miles.
 
From what I have learned here, you can also get a artificially inflated maximum range reading by doing an extended charge, then merely temporarily disconnect your 12V battery and reconnect it. Apparently, this resets the range computer to an initial default value of around 147 miles (or 3.5mi/kWh) to REALLY impress your friends! :mrgreen:
 
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