How to charge to 80%, then top up to 100%

I'm not sure where to post this, since it involves both the car and the EVSE, so I'm reaching out to two subforums. Perhaps someone has figured it out. Some background: I have a Siemens Versicharge (non-networked) and a 2013 SL. I drive the car very consistently, about 50 miles/day on weekdays and nearly nothing on weekends. It's a commuting appliance I typically return home around 6 and plug in immediately. The car sits at 100% for most of the night and almost all weekend. At my last service, the dealer said I should try to minimize parked time at 100%, so I'm trying to address this.

The Versicharge is good, but has limited programmability. I can either start a charge immediately by plugging in, or I can set a 2, 4, 6, or 8 hour start delay. The timer in the Leaf allows me to start/stop charges and choose either 80% or 100%, but is limited to one charge "event" per day and only one %age. Neither of those capabilities allow me to do this:

1. Arrive home 6pm with with approx. 30% battery.
2. Plug in and charge to approx. 80%. Stop charging.
3. At about 6am, start charging so the car is at 100% by 7am.

So, I need 2 "events" per 24 hours: an initial partial charge followed by a top-up. The Versicharge has a board-level remote switch which I have confirmed will work as a shutoff. Adding an external timer circuit will allow me to plug in and have the EVSE shut off after about an hour. Problem: 1) there are no instructions from Siemens on how to properly connect this. I am hoping someone here has done it. 2) I have yet to find a 2-event timer circuit.

Since my EVSE cannot sense charge %age (other than 100%), using the car's timer is nice, because it can be set to stop at a %age limit. However, it only handles one "event" per day. Using the car's timer together with an external timer seems like a good idea on paper, but the two programming techniques can conflict with each other.

Any ideas on how to accomplish the charging pattern in bold above?

Are you sure you're posting in the correct forum? The LEAF's timers can NOT be set to stop at arbitrary charge percentages, although in the first two model years (2011, 2012), the LEAF's timers did offered a choice of either 80% or 100%. If your routine is as consistent as you say, and if you actually DO have a LEAF, I would recommend just setting one of the timers for "END-only" charging for all weekdays, with a goal time of, say half an hour or so before your departure time. Sounds like you use 70% of your battery;s charge for each commute, so charging to 100% is appropriate . Otherwise, your daily routine would be the same: come home and plug in; charging will begin somewhere in the wee small hours of the morning, and your exposure to 100% charge levels would be only for the hour or so between the time it finishes charging and you drive off to work. I don't really understand why anyone would want to usea supplemental timer mechanism inside an EVSE,

Levenkay said:

Are you sure you're posting in the correct forum? The LEAF's timers can NOT be set to stop at arbitrary charge percentages, although in the first two model years (2011, 2012), the LEAF's timers did offered a choice of either 80% or 100%.

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'13 SV and SL also let you set 80% or 100% via timers. '13 SV and SL also added "long-life mode" 80% setting via the nav system that didn't require use of timers.

Levenkay said:

... if you actually DO have a LEAF...

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No, you're right. Just thought it would be fun to troll other Leaf owners by asking a technical question. :roll:

Levenkay said:

Are you sure you're posting in the correct forum? The LEAF's timers can NOT be set to stop at arbitrary charge percentages

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Actually, since I do own a Leaf, I know that the on-board charging timer can be set to stop at either 80% or 100%. Not arbitrary, but fine for what I need. The problem is that the car can't be programmed for both levels within the same day.

Levenkay said:

your daily routine would be the same: come home and plug in; charging will begin somewhere in the wee small hours of the morning, and your exposure to 100% charge levels would be only for the hour or so between the time it finishes charging and you drive off to work. I don't really understand why anyone would want to usea supplemental timer mechanism inside an EVSE,

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To immediately charge to 80% in the evening in case I need to drive again.

You may need to adjust the start and end times a little to achieve the desired results, but this should work for you. If you have it finish charging about an hour before departure time, you can also use the climate control timer to adjust the interior temperature to your preference.

Set a daily timer for 100% charge that starts at 2:20am and ends at 7:40pm. This will start an early morning charge cycle that ends at 100% before you are ready to leave. The timer will still be active when you connect at 6:00pm and start charging. The timer will stop charging at 7:40pm, leaving you around 80% full.

Here are two options:

1. Set Timer 1 for "today" at 80% with a start time around 5:30 pm and end time (say 11:30 pm) for the evening to ensure enough time for a 80% charge. If you normally get home at 6pm set start time a little early, say around 5:30pm so it will start charging when you get home and plug in. Then for tomorrow set Timer 2 with an end time only of 7am at 100%. Then "every day" when you get home (or before) simply access one of the Timers and change the days for both timers to match the days needed. It is quick and easy, just have to make a habit to make the Change in the days. I did something like this when I only wanted to charge to 80% both at home and at work but for specific times.

2. Set Timer 1 for Monday - Friday at 80% in the evenings, then in the Mornings go out to garage and hit the timer override button when you get up or around 6am to get the remaining 100%.

P.s. I personally prefer to not charge during the peak electric demand times when not needed.

Welcome to the forum, B!

I understand wanting to optimize the charging for the least impact on battery life. That's the kind of thing I'd do. But my guess is that just setting things up so that the car is charged up at 7 AM each weekday morning will accomplish your goal. IOW, a fancier scheme would probably not make much of a difference. I could be wrong.

And you could simply not plug it in on Friday and Saturday nights.

PianoAl said:

I understand wanting to optimize the charging for the least impact on battery life. That's the kind of thing I'd do. But my guess is that just setting things up so that the car is charged up at 7 AM each weekday morning will accomplish your goal. IOW, a fancier scheme would probably not make much of a difference. I could be wrong.

And you could simply not plug it in on Friday and Saturday nights.

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This is exactly what I do. The only difference is a couple of days I charge to 80% and a couple I charge to 100%. Sitting at 100% for an hour or two (in the morning) isn't nearly as bad as sitting there all night.

PianoAl said:

Welcome to the forum, B!

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Thanks!

PianoAl said:

...my guess is that just setting things up so that the car is charged up at 7 AM each weekday morning will accomplish your goal. IOW, a fancier scheme would probably not make much of a difference.

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Yes and no.

Yes, the setup you describe preserves battery life (per Nissan's advice) by limiting the amount of time sitting idle at 100% charge.

No, because with this setup, charging does not begin until the dawn hours. This leaves me with limited mileage if I want to use the car in the evening after my commute.

I realize I could manually do a partial charge, get up earlier, etc., but it seems like this could (and should) all be automated. The Versicharge actually has a board-mounted remote switch designed for the power company to toggle the EVSE remotely, so it doesn't seem far-fetched to exploit this function. Just wondering if anyone here has.

The concern seems to be "Spontaneous errands that require more than the 30% capacity I typically return from work with, but I fortunately only discover I need to make just as the charging session that I began the moment I returned home has replaced enough charge to make them". Hmm. I have to agree that something more convoluted than the car's charging arrangements are called for. You'd want an EVSE that makes itself available for charging only, say, from 04:00 to 20:00 each day. That way, a car returning at 18:00 would enjoy two hours of "just in case" charging, but wait until 04:00 to resume charging to 100%.

Levenkay said:

The concern seems to be "Spontaneous errands that require more than the 30% capacity I typically return from work with, but I fortunately only discover I need to make just as the charging session that I began the moment I returned home has replaced enough charge to make them". Hmm.

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I call that "take my wife's car" (not that it ever happens).

Stanton said:

Levenkay said:

The concern seems to be "Spontaneous errands that require more than the 30% capacity I typically return from work with, but I fortunately only discover I need to make just as the charging session that I began the moment I returned home has replaced enough charge to make them". Hmm.

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I call that "take my wife's car" (not that it ever happens).

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Yep. I use my Land Cruiser for that. Quite the opposite of a Leaf. 12mpg downhill with a tailwind.

Levenkay said:

The concern seems to be "Spontaneous errands that require more than the 30% capacity I typically return from work with, but I fortunately only discover I need to make just as the charging session that I began the moment I returned home has replaced enough charge to make them". Hmm. I have to agree that something more convoluted than the car's charging arrangements are called for. You'd want an EVSE that makes itself available for charging only, say, from 04:00 to 20:00 each day. That way, a car returning at 18:00 would enjoy two hours of "just in case" charging, but wait until 04:00 to resume charging to 100%.

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Nice idea. Should be given a try.

i never use timers. what I do is simply plug it in right before going to bed so it finishes charging generally a few hours before I leave in the morning. you don't drive it on weekends there is no reason it cant sit until Sunday night before plugging it in.

I always felt that charger settings become more of a hassle especially if your schedule varies a lot like mine does. I don't want to think about the charger restrictions since my leave time in the "morning" can frequently be as early as 2 am.

but then again, my method has drawbacks for some. it can be easy to simply forget to plug in but I have done well so far and yeah, there is perhaps a handful of times, I would be in bed then remember and get up to plug in car but that usually happens in the first few minutes. I have had a lifetime habit of reviewing the day and thinking about the day ahead. undeniable habits bred from a schedule that varies every day I guess. its not something I consciously do, it just happens.

FYI; times I forgot to plug in, maybe 2-3 times? in 8+ years. Times I remembered I needed to take something in the morning and decided against putting it in the car the night before thinking I would be ok only to turn around a few blocks down the street to get it; not sure but "hoping" its less than 100 times...

One option would be to hit a QC when you get home and bring it up to 70-80% the use an end timer to bring it to full by morning. That would minimize the time at 100% and give you some charge to use if you need it on demand.
The disadvantage to that would be if it's really hot when you get home from work as QC raises the battery temp quite a bit.
Or do what Levenkay mentioned.

One of the things the annual battery check does is determine if you charge the battery when already at a high state of charge. Having the battery at 80% and recharging to 100% will meet that criteria.

Not sure what Nissan does with that information, or if it degrades the battery excessively. I just know that they check it.

If one is going to charge up to 100% anyway (as Nissan now all but forces the LEAF to do), the last stages of such charging sessions are inevitably "charging at high states of charge". What earthly difference could interrupting that process temporarily make, other than providing an opportunity for beneficial cooling?

Well Bibendum, What did you decide to try/use?

bbrowncods said:

One of the things the annual battery check does is determine if you charge the battery when already at a high state of charge. Having the battery at 80% and recharging to 100% will meet that criteria.

Not sure what Nissan does with that information, or if it degrades the battery excessively. I just know that they check it.

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Good question - will they push back on a battery warrantee because you keep a (degraded battery with limited range) at near 100% at all times - so you can take a 40 - 50 mile trip whenever needed??? With a new 90 mile range battery, not such an issue, but it sure is for me as I use it all the time for any suburban trip.