The 40KWH Battery Topic

[jmurtagh13]

Whats the climate where you live? Is car garaged?

I live in Atlanta, yes it's hot here in the summer. The car is parked under a large tree so it does not get any direct sun. The battery temperature stays mostly between 80 and 85 Deg. during the summer. During the work week the car is in a parking garage during the day.

[jmurtagh13]

I set my car time to the following settings, the "Full charge has priority" is the key one. I then have a timer on my charger that shuts it off at 7:00am. Then regardless of the charge level by 7:00am it will always be at or about 70%. I only charge at 3KW so my stop time is way out to 11:00am but if you're charging at 6KW it would probably by more like 10:00am for 70%

I like it !
Clever.

To be clear for others, 'charger' refers to the EVSE

Yes that's correct, my bad.

[SageBrush]

I set my car time to the following settings, the "Full charge has priority" is the key one. I then have a timer on my charger that shuts it off at 7:00am. Then regardless of the charge level by 7:00am it will always be at or about 70%. I only charge at 3KW so my stop time is way out to 11:00am but if you're charging at 6KW it would probably by more like 10:00am for 70%

I like it !
Clever.

To be clear for others, 'charger' refers to the EVSE

Yes that's correct, my bad.

No worries.

If I may clarify one other sentence of yours for others --
"Then regardless of the charge level by 7:00am it will always be at or about 70%. "
means regardless of the starting SoC, the car SoC will be at 70% at 7am.

jmurtagh is taking advantage of the predictable and consistent time it takes his EVSE to increase the car SoC from 70 to 100%. As I said -- Clever.

[SageBrush]

jmurtagh's solution is elegant in that he doesn't have to calculate anything, or remember a particular time to plug/unplug.
He plugs in when he arrives home, and is DONE.

He did not say how he turns off power at the EVSE at 7am. I think the JuiceBox has that feature, but others with dumb EVSEs could wire in a timer that costs ~ $50

[SageBrush]

You get the point...works for me.

Heh.

There would be revolution in the air if my wife had to fiddle with the charge timer settings after every drive. Even I would tire of that requirement pretty darned quick.

[jmurtagh13]

jmurtagh's solution is elegant in that he doesn't have to calculate anything, or remember a particular time to plug/unplug.
He plugs in when he arrives home, and is DONE.

He did not say how he turns off power at the EVSE at 7am. I think the JuiceBox has that feature, but others with dumb EVSEs could wire in a timer that costs ~ $50

I installed a pool pump timer that just turns on/off the outlet the EVSE is plugged into.
I have it set to turn off at 7:00am and then back on at 5:00pm.

This was the only way I could get my wife to charge the car in keeping it at 70%, all she has to do is plug it in.

https://www.amazon.com/Intermatic-T101- ... r=8-7&th=1

[DaveinOlyWA]

jmurtagh's solution is elegant in that he doesn't have to calculate anything, or remember a particular time to plug/unplug.
He plugs in when he arrives home, and is DONE.

He did not say how he turns off power at the EVSE at 7am. I think the JuiceBox has that feature, but others with dumb EVSEs could wire in a timer that costs ~ $50

His process isn't that far off from mine. I had my 40 kwh set to finish a charge at 10 AM same setup. but always left for work at 7 AM so no EVSE shut off needed, I simply unplugged and left. Was at 65% +/- 2% or so every day. I only did this during Winter. During Summer, it was too easy to DC instead when it was free.

[SageBrush]

jmurtagh's solution is elegant in that he doesn't have to calculate anything, or remember a particular time to plug/unplug.
He plugs in when he arrives home, and is DONE.

He did not say how he turns off power at the EVSE at 7am. I think the JuiceBox has that feature, but others with dumb EVSEs could wire in a timer that costs ~ $50

His process isn't that far off from mine. I had my 40 kwh set to finish a charge at 10 AM same setup. but always left for work at 7 AM so no EVSE shut off needed, I simply unplugged and left. Was at 65% +/- 2% or so every day. I only did this during Winter. During Summer, it was too easy to DC instead when it was free.

In your case, *you* are the timer. Your solution is the same one I thought of when people would come to the forum looking for a solution. It's obvious weakness is that it only works well when the time of departure is about the same each day the car is plugged in.

[DaveinOlyWA]

jmurtagh's solution is elegant in that he doesn't have to calculate anything, or remember a particular time to plug/unplug.
He plugs in when he arrives home, and is DONE.

He did not say how he turns off power at the EVSE at 7am. I think the JuiceBox has that feature, but others with dumb EVSEs could wire in a timer that costs ~ $50

His process isn't that far off from mine. I had my 40 kwh set to finish a charge at 10 AM same setup. but always left for work at 7 AM so no EVSE shut off needed, I simply unplugged and left. Was at 65% +/- 2% or so every day. I only did this during Winter. During Summer, it was too easy to DC instead when it was free.

In your case, *you* are the timer. Your solution is the same one I thought of when people would come to the forum looking for a solution. It's obvious weakness is that it only works well when the time of departure is about the same each day the car is plugged in.

Yep, work commute so departure time varied in a 5 minute window. I did the same on days off with roadtrips planned. I am not a jump out of bed and take off person. I do coffee routine that lasts AT LEAST an hour before I do anything else. On days I wanted a full charge, I simply plugged in at bedtime. My normal SOC meant charge completion and departure was no more than a few hours. On other times when full charge wasn't desired, I would set it to start at like 4 AM or whatever based on my expected departure time and a 10% per hour charge rate.

In either case, it is hardly inconvenient.

[SageBrush]

In either case, it is hardly inconvenient.

To you. Or to me. Both of us look at the SoC gauge every time we park at home.

However, the country is stuffed with people who only add fuel to their cars when the car beeps and flashes an "ADD GAS" alert. These people have no clue about the status of their fuel tank (or battery SoC, as the case may be) at any other time and they want to keep it that way. Moreover, realize that a sizable fraction of EV drivers are like this, AND are driving an EV in no small part either to save money or because of a pushy spouse. Accommodating EV idiosyncrasies is not part of their daily agenda.

As jmurtagh so cheerfully noted, he was lucky to convince his wife to plug in daily. The rest was on him and the car. In case you are wondering, no particular perceptiveness on my part. But my wife does have a similar outlook and fuse.