Automatic Charging and Climate Timing?

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Dan Albrich

Well-Known Member
I was recently fortunate enough to add a level 2 charger. One feature I've enjoyed is the scheduled climate control. In my case I set for about 7am for 730am departure. I notice I sometimes gain 1 mile of EV range as the car pre-heats which I was not expecting. i.e. if I go to bed to 28 miles of estimated EV range, by morning I'll see 29 miles after climate control.

So I need to add- My local utility has no ability to do time-of-day rates. The rates are not effected at all by time.

So the questions:
- Does it help given no cost-savings advantage by time to charge the car shortly before leaving for work? (what I do now is plugin whenever I get home and charge in the evening).
- If I'm also doing climate control, is it best to do before, during or after charging? (or is this unrelated to the charge time question?

Input welcome.

-Dan
 
Beware if you turn on climate control with a partial charge, it will drastically increase your charging time.

Because if the heater for example is drawing 5,000 watts while conditioning (common), and the charger can only put out about 7,000 watts, the battery is only charging at 2,000 watts, slowly. Wheras if you have climate control shut off, the battery is receiving the full 7,000 watts, and charging quickly.

So to answer your 1st question question, I'd just plug in when you get home, so it's fully charged early and quickly, and set it to warm up when you want it to. With no variation in electric rates you have nothing to gain by doing it differently.

Don't put any stock in that extra mile you think you gained. It's just an estimate, and doubtful a gain in range actually occurred.
 
craze1cars said:
Don't put any stock in that extra mile you think you gained. It's just an estimate, and doubtful a gain in range actually occurred.
Click to expand...

Agree. When you precondition, you also trigger a new charging session, so the EV guess-timator takes another crack at it, and may factor in something like "since the last charging session, the car's used the battery a little more efficiently!"
 
To add to the above, I’ll mention that the charging graphs on my Charge Point EVSE show that the preconditioning may draw to 5 kWs at its peak but does not draw 5 kW for the entire time it’s on. So for the 30 min that it was on in a 35 F garage last time, it only used less than 1.5 kWh not the 2.5 kWh you would expect at 5 kW for 1/2 hour. It draws a lot at first but as the car warms up it draws less and will cycle up and down as needed.
So in my experience it doesn’t drastically slow down charging times since it’s only on for 30 min and usually siphons off only 1.5 kW (maybe some more if outside at lower staring temps). Significant yes, drastic no.

I base this on the fact that the most anyone has reported drawing from their EVSE on one charge from 0 EV is 14.4 kW and that takes about 2 hours and 10 min. That works out to charging about 0.11 kW/minute, so siphoning off 1.5 kW to PC should only add about 17 minutes to the charging time and only 22 min if PC used 2 kWs.
Please check my math and set up on this. I am not an EE and am spitballing this.

As @craze1cars suggests, it’s best to have your charging session end before you PC to make sure you drive away with a full charge.
FWIW, preconditioning on EVSE power and not the battery is letting me use occasional seat heater and no cabin heater so I’m getting low 50 mile range even in the 20s F (down from mid 60s before winter hit).
 
Thank you for the helpful replies. I'll likely just keep things as they are (i.e. not schedule charging).
This has the advantage that if on some days (i.e. weekends) I charge more than once per-day, I don't have to hold the charge button to override the schedule.

-Dan
 
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