Charging to 100%

Hi I am planning on doing a 60 to 70 mile journey next week, and have read that the charger only charges the battery to around 80% capacity, to preserve the life of the battery. If after a full charge I unplug the charger and then plug it back in will it charge the battery to nearer 100%, and is it ok to do this occasionally

Couple of different answers.

1. The LEAF has the option to select 80% or 100% charge.
2. CHAdeMO will stop at 80%, then a replug will slow charge to full.
3. A "full charge" on the i's charge gauge is not a full battery. If you mean to charge until the gauge says full, then replug to charge more, the I won't do this.

PV1 said:

Couple of different answers.

1. The LEAF has the option to select 80% or 100% charge.
2. CHAdeMO will stop at 80%, then a replug will slow charge to full.
3. A "full charge" on the i's charge gauge is not a full battery. If you mean to charge until the gauge says full, then replug to charge more, the I won't do this.

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Thanks I just want to make sure I have absolute Maximum range when I start this journey. Most of my journeys are local so no problem

The charger shuts off at it's recommended state of charge - You can't adjust that and plugging it in again doesn't gain you anything

Limit your speed as much as possible on the outward leg and use as little climate control as you can get by with. You'll see where you're at when you begin the return trip. Some folks have gone 100 miles on a single charge with no topping off and the secret is . . . . lower speeds

Don

Many thanks for your advice ANDY

I would argue that unplugging, waiting up to an hour and plugging back in would probably give you an extra percent or two

fjpod said:

I would argue that unplugging, waiting up to an hour and plugging back in would probably give you an extra percent or two

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But would that be good for the battery?

Original poster -- the range meter is dependent on how you've driven over the past 15 miles or so... which is why you might see it read 72 or 92 after a full charge, depending on whether you were most recently on a highway or on flat backroads or whatever.

ANDY4004, is it 60 miles or is it 70 miles? Big difference, as 60 miles is no sweat if you're even slightly careful even if it's all Interstate, but 70 miles you need to start being pro-active. Don's recommendation is right on: keep your speed way down and you should be able to get to your destination with a couple of bars remaining. Simply let the car fully charge with the charger shutting itself off just before you leave. I would not try to charge it again once it has stopped (there's even a caution about this in the Manual). You might read up on hypermiling and perhaps put a few of those tricks into practice. Do you have an opportunity to stop for coffee and a partial charge along the way, and are you time-constrained? If you're time-constrained, I wouldn't bother and would simply take an ICE car. Otherwise, you'll have a nice mini-adventure. In any case, don't forget to take your EVSE with you. BTW, where are you located?

fjpod said:

I would argue that unplugging, waiting up to an hour and plugging back in would probably give you an extra percent or two

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It takes more than unplugging and replugging to get rid of an esophagus cramp in the BMU but it can be done.

Quercus said:

But would that be good for the battery?

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The manuals say no, do not even try to charge again after fully charging.

Please excuse me not telling you how to ...

Those knowing wont do it because they know what it does. Those not knowing should not even think about it. Remember those airplanes on the ground for a week or so?

I normally wouldn't go through the trouble of unplugging and replugging to gain a few miles, but do you really think MM hasn't built in a top level to the BMS that won't turn off the juice when maxed out? Of course they did.

Suppose my car was plugged in and the battery fully charged, and the power in my house goes out for ten minutes due to a storm. When the juice comes back on, the EVSE will start up again and charging will resume...for a short while. When the BMS re-achieves the top level of charge, it will shut off just as it should, perhaps leveling the cells a little bit better.

Nothing will go wrong. Planes won't fall out of the sky. Sure, one could argue that keeping your battery at the highest state of charge is not good for it's ultimate lifespan, but it will give you that fuller range you are looking for.

ANDY4004 said:

Hi I am planning on doing a 60 to 70 mile journey next week, and have read that the charger only charges the battery to around 80% capacity, to preserve the life of the battery. If after a full charge I unplug the charger and then plug it back in will it charge the battery to nearer 100%, and is it ok to do this occasionally

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I don't have the facts in front of me but as best I remember our MiEVs are programmed to charge to something like 90% (not 80%) when they say there are fully charged. Whatever the limit, the intention is to make your battery's long range life longer than if charged to 100%. You probably knew that.

It is my understanding that when your battery gets old and lowered capacity to the point where you need to replace it because it simply does not have enough capacity for your use, you can go into a dealer and they can reprogram it to charge closer to 100%.

In our owners manual it specifically says don't plug the charger back on after doing a full charge. Undoubtedly because as you suspect it would start charging and put on a charge somewhat higher than the normal stopping point. We don't know exactly what that behavior is and what the long or medium range consequences or costs of doing that might be.

If you need to maximize your useful range IMOprobably better to figure out if you can extend the range by driving slower (leave very early) and/or try to find somewhere (even 120 volt) where you can put on a partial charge partway there. Or loan your EV to a friend or neighbor in exchange for borrowing his/her ICE car for that occassional borderline or excessive range trip.

Don said:

The charger shuts off at it's recommended state of charge - You can't adjust that and plugging it in again doesn't gain you anything......
Don

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Don,
Per my earlier post, I am under the impression that in fact replugging it in after a full charge will at least briefly continue to charge, and that is why the manual (don't have it in front of me at this moment, but am 99% sure I read this there) specifically says DON'T plug the charger back on the car after a full charge.

Are you sure I'm wrong about that? And if so, why would Mitsubishi put that "don't do that" note in there?

I have watched ours with an ampere meter. It did its' selftest but it did not draw amperes before shutting off.

Same result after waiting a day.

acensor said:

Don said:

The charger shuts off at it's recommended state of charge - You can't adjust that and plugging it in again doesn't gain you anything......
Don

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Don,
Per my earlier post, I am under the impression that in fact replugging it in after a full charge will at least briefly continue to charge, and that is why the manual (don't have it in front of me at this moment, but am 99% sure I read this there) specifically says DON'T plug the charger back on the car after a full charge.

Are you sure I'm wrong about that? And if so, why would Mitsubishi put that "don't do that" note in there?

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Who knows? Likely I don't know any more about it for a fact than you or anyone else here. Mitsu give us very few "Don't do this . . . " warnings in the owners manual, so I'm not going to try it (because Mitsu says not to) but I believe if you plug it back in when it's already full, the red light would indeed light up (indicating it's charging) but I think all you would be accomplishing is another cell top balancing dance, which is what the BMS does after the pack reaches the computed max charge voltage. As to whether this would extend the range of the car on a drive following the 'double charge' I really doubt it. It might go one or two miles further, if the second cell balancing adds a small charge to the weakest cells but I don't think you'd see a measurable difference and I really doubt that you would be charging the entire pack to a higher voltage on the second charge . . . . but this is all just speculation on my part

I spend a good deal of time thinking about how I might make the very expensive battery pack in my car last a little longer than everyone else's, but I spend very little time wondering what would happen if I do something Mitsu very plainly says not to do . . . . . .

Don

ANDY4004 said:

Hi I am planning on doing a 60 to 70 mile journey next week, and have read that the charger only charges the battery to around 80% capacity, to preserve the life of the battery. If after a full charge I unplug the charger and then plug it back in will it charge the battery to nearer 100%, and is it ok to do this occasionally

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Make sure you have a plan to recharge along the route if need be. I once took my car up to a city that I thought I could easilly make on my range but the weather had it in for me and I didn't quite make it. I don't own a smart phone, so I had looked up Charging Locations along my route ahead of time and got all of the addresses. There aren't many in my region but I did have a few I could use. One of them happed to be a small Mitsubishi dealership in Hamilton, Ontario. I thought the charger would be outside but I didn't see it as I drove around the building. Went inside and asked about it and no one knew what I was talking about. I was in a total panic but finally a mechanic came out from the garage and said, "Yeah, we have one of those - just got it installed." I left my car there to charge and took a cab to the hospital where my son had a medical appointment. They were very accomodating, even tried to get me a ride but their shuttle was busy. I sent them a thank you letter.

Just be prepared, relax, carry a GPS to monitor your progress on your trip, make sure to carry your portable EVSE and have a handful of places where you can charge - just in case!

JoeS said:

ANDY4004, is it 60 miles or is it 70 miles? Big difference, as 60 miles is no sweat if you're even slightly careful even if it's all Interstate, but 70 miles you need to start being pro-active. Don's recommendation is right on: keep your speed way down and you should be able to get to your destination with a couple of bars remaining. Simply let the car fully charge with the charger shutting itself off just before you leave. I would not try to charge it again once it has stopped (there's even a caution about this in the Manual). You might read up on hypermiling and perhaps put a few of those tricks into practice. Do you have an opportunity to stop for coffee and a partial charge along the way, and are you time-constrained? If you're time-constrained, I wouldn't bother and would simply take an ICE car. Otherwise, you'll have a nice mini-adventure. In any case, don't forget to take your EVSE with you. BTW, where are you located?

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HI It was a 72 mile round trip . There was a place to charge on way home so wasn't too worried, however I did the round trip with no charging and had 4 miles left on the range indicator, and one bar flashing. I plan to do this journey every 2 weeks and have got the option to part charge on way home if needed. I don't know if running the battery right down every 2 weeks will do any harm What do you think?

I'll bet the next time you do it, you'll have 6 miles RR when you get home and probably 8 or 10 the time after that . . . . assuming you're trying to get the best mileage possible. The longer you drive the car, the better at this you get

I don't think a discharge down to 1 or 2 bars every couple weeks is going to have a measurable effect on anything

Don

ANDY4004 said:

HI It was a 72 mile round trip . There was a place to charge on way home so wasn't too worried, however I did the round trip with no charging and had 4 miles left on the range indicator, and one bar flashing. I plan to do this journey every 2 weeks and have got the option to part charge on way home if needed. I don't know if running the battery right down every 2 weeks will do any harm What do you think?

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It's actually recommended to do everyone once in awhile to reset the BMS or something like that. Glad to hear you made it with no problem. The i-MiEV is a ver good electric car and will carry you a lot further than the EPA estimate.

yesterday, I actually tried unplugging my EVSE about an hour after it had completed a charge. When I plugged it back rignt in, It went on for a startup cycle, complete with fan noise, but then turned off almost immediately. I tried it three times. So, fully charging, then unplugging and retrying for a greater charge produces no increased range. Maybe if the car had been sitting at full charge for a few days...but who would do that anyway.