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Best Commuter Charging Practices

Posted: Thu May 10, 2018 11:33 am
by TobyGadd
I'd love some educated opinions on the best charging practices for my i-miev.

Here are the details:
I pretty much only use the car for commuting. I often commute 7 days a week, about 15 miles each way (30 miles/day). There's free charging at my office, so I generally like to charge there, not at home. I can't easily stop the charge before 100% since the car is in a garage away from the office. With my driving practices and route, I get about 65-75 miles per charge (without heat or AC). Each direction uses ~20% SOC, or 40% per day.

So, here's the question: Is it better to charge every day, with a starting SOC of ~60%? Or is it better to charge every other day, with a starting SOC of ~20%?


Re: Best charging practices

Posted: Thu May 10, 2018 7:40 pm
by Don
IMO, every other day is ideal . . . . but doing that may leave you getting a bit short on some of those alternate days, especially in the winter and that's not good. Use discretion and maybe give it a little bump before you leave home on those second mornings while you have your coffee :D


Re: Best charging practices

Posted: Thu May 10, 2018 8:29 pm
by JoeS
TobyGadd wrote:...There's free charging at my office, so I generally like to charge there, not at home...
Dumb question: is that a L2 charging station or a wall outlet that's dedicated to only you?

I would use the Remote. Once you learn to use it, it's really quick and easy. If you have a regular daily routine you might not need to reprogram it, but you still need to enable it. If your charging is L2, then you get three bars/hour. If your charging is L1 8A, then you get four bars for five hours. If your charging is L1 12A, then you get six bars for five hours.

I would charge every day at work (lucky you!), and simply set the Remote so it stops charging at, say, 14 bars, just as you leave work. Your round trip will consume about eight bars so you will arrive at work the next day with six bars. This way you will still have plenty of charge left to run errands before/after work if you need to. Doing this will keep the battery in the middle of its SoC and avoid deeper cycling.

Re: Best charging practices

Posted: Fri May 11, 2018 11:55 am
by TobyGadd
I love the idea of using the remote!

It's level 2 charging. I'll check to see how many amps it puts out, and adjust the time accordingly.

Thanks for your insight and ideas!

Re: Best charging practices

Posted: Sat May 12, 2018 5:15 am
by PV1
My commute is 23 miles, which usually leaves me with around 11 bars (9-10 in the winter, usually 12 in the summer). I fully charge every night when I'm driving the i-MiEV the next day.

Since you have level 2 charging at work, giving the car 2 hours of charging per day ought to keep it from fully charging (that top bar could take an hour or more to complete due to tapering and balancing), but still get it pretty close. What you can do is program the ON timer for 2 hours and the ON->OFF timer for 4 hours when you arrive at work and plug in. This will delay charging for two hours to let the battery cool down a bit, then charge for 2 hours, and then stop. Once the timers are set, subsequent days will remember the times, though you will have to cycle through the timers and hit the right arrow button once for each timer to enable them, and then press send. The button sequence to enable the timers after setting them the day before are:

Hold power --> Right arrow once --> Mode --> Right arrow once --> Send

What's nice with how the timers work, is that if you get to work late or early, the same button sequence will have the start and stop charge times end up being at nearly the same times of the day as normal. Even though they appear as simple timers, the car uses the values and adds it to the current time of day to set trigger times. So, a 2 hour delay set at 8 AM will start charging at 10 AM. If you get to work at 7 AM one morning and go to enable the timers, it'll say 3 hours instead, so that charging still starts at 10 AM.