how to charge to 80% on model SL?

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eKrom

Member
Joined
Jul 30, 2020
Messages
12
Location
Bay Area, CA
Hi,

It appears there is no way to limit Gen1 Leaf Model SL (7" infotaiment) to automatically stop charging at 80%?

I have tried to time it with the build-in Charge Timer but the leaf did not stop charging at given time. I suppose it does not as it was not full. So this timer is useless.

A more complicated method would be to have LeafSpy sending alarm when 80% is reached or better yet posting charge state to a MQTT server and have a OpenEVSE charger auto turned off by it.

So why would NIssan not provide this option in SL and have their cars break the battery faster? Or am I missing something?

Thanks,
Michal
 
eKrom said:
Hi,

It appears there is no way to limit Gen1 Leaf Model SL (7" infotaiment) to automatically stop charging at 80%?

I have tried to time it with the build-in Charge Timer but the leaf did not stop charging at given time. I suppose it does not as it was not full. So this timer is useless.
Some model years have an option to charge up to 80%, most do not.
If your car use starts at the same time of day, try setting the 'finish at' timer to about an hour *after* you plan to leave. You will have to tweak this a bit based on your charging rate and battery capacity.
 
See Dala's "BatterySaver" product offering here:

https://dalasevrepair.fi/#products

Not sure if he would sell you just the modified muxsan canbus device though, as his core business is EV repairs and battery pack upgrades.

Demo here on how it works:

https://youtu.be/yJvrB6aw5Ys
 
How difficult is it to mentally calculate the needed capacity (kWh based on present SOC) to achieve 80% SOC, and divide that by your EVSE charge rate
to determine a needed time? It takes me less that three seconds to set my start time to end at 6:00 AM on either of my two Leafs, knowing my L2 charge rate is about 5kW/hr. Even your middle school kid or grand kid would find it an easy effort, if you need help! An error of +/- 5% will be adequate to achieve
the desired result (max SOC ~ 80%).
 
eKrom said:
So why would NIssan not provide this option in SL and have their cars break the battery faster?

I don't think Nissan has ever officially answered this but the suspicion is that the EPA reduced or threatened to reduce the Leaf's mileage rating to the mileage expected when it was charged to 80% SOC. After Nissan removed that option the EPA rated the car at 100% SOC.
 
By the way, people worried about 100% SoC degrading the battery should realize that the time at 100% SoC is really important. So by all means charge to less than 100% SoC if you are able, but more importantly, minimize the time that the car is sitting at whatever maximum charge you decide on. This is particularly true in the hot summer.

Another advantage of charging in the early morning (say, 4 am to 8 am window) is that ambient temps are lowest for the day.

Our 2013 LEAF charges to 80% in the morning. It is at a SOH of 83% which is far from great, but a lot better than almost all other LEAFs that live in a similar climate to ours in Colorado/New Mexico. I suspect that part of the reason is a diet of charging that avoids high pack temperatures and minimizes time at a high SoC
 
The easy but not cheap way would just be to buy a Juicebox EVSE. It has that function. It kinda figures it out based on charge time, calculated remains capacity etc. It takes a few times to get good at it (you have to tell it what your current charge is so a little guessy) but other than having to spend 3 or 5 seconds in the APP every time it’s pretty close. 3 or 5 percent either way. Meh. I used it often on the leaf. Works good.

To be clear. Juicebox pro 40.

And as far as accuracy goes, our model 3 is usually out a couple percent when we try and set it to 80 percent.
 
SageBrush said:
lorenfb said:
knowing my L2 charge rate is about 5kW/hr.
**cough**

Don't the electric companies have meters installed on dwellings in NM? SCE provided free ZigBee power monitoring devices to its customers,
eliminating the need to actually view the SCE meter.
 
I used to use the charge timer, but would forget to turn off the timer when traveling around, and them realize too late that my l2 charge didn't happen as it wasn't 2-6am when my timer was set up to go.

My super awesome covid era solution is to plug in the car and set the microwave or Alexa timer to beep when it's time to unplug the car.
 
goldbrick said:
eKrom said:
So why would NIssan not provide this option in SL and have their cars break the battery faster?

I don't think Nissan has ever officially answered this but the suspicion is that the EPA reduced or threatened to reduce the Leaf's mileage rating to the mileage expected when it was charged to 80% SOC. After Nissan removed that option the EPA rated the car at 100% SOC.
It was removed from US Leafs starting with model year '14. It remained around longer in some countries (e.g. '15 in Ireland had it) until it totally went away.

https://insideevs.com/news/317213/2013-nissan-leaf-rated-at-75-miles-but-84-miles-using-the-outgoing-2012-epa-ratings-system/
https://insideevs.com/news/320736/2014-nissan-leaf-mostly-unchanged-as-range-technically-moves-up-to-84-miles/

Yes, it seems likely that Nissan eliminated it for the above reason. Back in 2014, a 75 mile range car didn't look too competitive amongst sub-100 mile EVs back then. 84 miles is near top of what was available in that price range.
 
Hey all!

Thanks for all the discussion here! I am new to EV, my Leaf is 3 week old (with me).

I am all for no-effort, plug and forget (as I am very forgetful). So any manual "3rd grade math to compute start time" would mean I will forget in the heat of the day to set it right (human factors). Likely also, the charging is not time-linear so you'd need a some polynomial function to estimate the time (not longer 3rd grade). Also, I am not fun of waking 4am to unplug it. Perhaps I should have stressed in original question an "AUTOMATIC" way. Not to mention my wife is the one in need of this ;-)

Thanks to the input I found this, very interesting:
https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3

It suggests that the OBD-II has all the inputs and outputs necessary to implement a smart car feature extender, I wish the LeafSpy had a charge alarm feature. at least...Could be a cool DIY project.

It sounds very sad if the EPA is so stupid to force car manufacturers to maneuver around such features. I have looked at BMW i3 where the range extender REX is disabled in US model until the battery is depleted (there was a hack to re-enable it). US still is learning the law of unintended consequences, eh?

The end time timer does not work for me - it does not stop charging at set hour. I think it's really a "start time" that is automatically computed given the expected full charge at entered time. But hence it does not stop charging automatically it useless.

The best point is that it's a-OK to charge to 100% as long as the car is not sitting fully charged for long. Now how "long" is long?
 
Long would be more than 3 hours or so in hotter weather, 12-18 hours or so in cooler weather. In frigid weather, we don't worry much about it.

The trick to using the end timer is to set it for a time the car can't possibly be fully charged at, and to disable the "Full Charge Priority" feature in the menu. I think it's called that, anyway. I suspect that it's enabled in your car, meaning that the car essentially disregards what you want, and tries to correct your 'mistakes' in timer setting in order to get a full charge.
 
eKrom said:
I am all for no-effort, plug and forget (as I am very forgetful). So any manual "3rd grade math to compute start time" would mean I will forget in the heat of the day to set it right (human factors). Likely also, the charging is not time-linear so you'd need a some polynomial function to estimate the time (not longer 3rd grade). Also, I am not fun of waking 4am to unplug it. Perhaps I should have stressed in original question an "AUTOMATIC" way. Not to mention my wife is the one in need of this ;-)
...
It sounds very sad if the EPA is so stupid to force car manufacturers to maneuver around such features. I have looked at BMW i3 where the range extender REX is disabled in US model until the battery is depleted (there was a hack to re-enable it). US still is learning the law of unintended consequences, eh?

The end time timer does not work for me - it does not stop charging at set hour. I think it's really a "start time" that is automatically computed given the expected full charge at entered time. But hence it does not stop charging automatically it useless.
FWIW, every Leaf I've plugged in model year 2013+ including gen 2's, while on level 2 (via ChargePoint graphs since I plugged in all sorts of EVs/PHEVs at work before lockdown) charge at full power (yes, linear) from empty until they're nearly full. When near full, there's a ramp down and usually 2 or bounces (examples at https://www.mynissanleaf.com/viewtopic.php?p=490435#p490435 and https://www.mynissanleaf.com/viewtopic.php?p=521788#p521788).

Can you set only an end timer with an end time several hours after you plan to leave/unplug?

As for EPA stupid or whatever, AFAIK, the BMW i3 REx crippling was due to them wanting to be classified as a BEVx and related to CARB (California Air Resources Board). Hopefully someone came chime in w/the correct/more complete story. Yes, it is really dumb about the 80/100% averaging rule. Supposedly, gen 2 RAV4 EV was hit by this.

For some reason, Tesla's been able to get away with this for years w/UI that lets you charge to whatever % you want. 2017 and 2018 Bolt had a hilltop reserve toggle. Turning it on made it not charge as full. 2019+ Bolt have UI that lets you limit charge anywhere from 40 to 100% in 5% increments. Current HyunKia EVs also have some charge limiter UI, I believe in 10% increments and even separate settings for AC vs. DC charging.
 
cwerdna said:
eKrom said:
I am all for no-effort, plug and forget (as I am very forgetful). So any manual "3rd grade math to compute start time" would mean I will forget in the heat of the day to set it right (human factors). Likely also, the charging is not time-linear so you'd need a some polynomial function to estimate the time (not longer 3rd grade). Also, I am not fun of waking 4am to unplug it. Perhaps I should have stressed in original question an "AUTOMATIC" way. Not to mention my wife is the one in need of this ;-)
...
It sounds very sad if the EPA is so stupid to force car manufacturers to maneuver around such features. I have looked at BMW i3 where the range extender REX is disabled in US model until the battery is depleted (there was a hack to re-enable it). US still is learning the law of unintended consequences, eh?

The end time timer does not work for me - it does not stop charging at set hour. I think it's really a "start time" that is automatically computed given the expected full charge at entered time. But hence it does not stop charging automatically it useless.
FWIW, every Leaf I've plugged in model year 2013+ including gen 2's, while on level 2 (via ChargePoint graphs since I plugged in all sorts of EVs/PHEVs at work before lockdown) charge at full power (yes, linear) from empty until they're nearly full. When near full, there's a ramp down and usually 2 or bounces (examples at https://www.mynissanleaf.com/viewtopic.php?p=490435#p490435 and https://www.mynissanleaf.com/viewtopic.php?p=521788#p521788).

Can you set only an end timer with an end time several hours after you plan to leave/unplug?

You're correct! That's what makes it easy to setup various simple charging methods.
 
eKrom said:
The end time timer does not work for me - it does not stop charging at set hour. I think it's really a "start time" that is automatically computed given the expected full charge at entered time. But hence it does not stop charging automatically it useless.
Is the first use of the car at a similar time of the day ?
 
Dala's solution is both simple and inexpensive. Why not explore that option?

If he won't sell you a modded version, the muxsan can bus bridge can be purchased here:

https://www.tindie.com/products/muxsan/can-mitm-bridge-3-port-rev-25/

And the source code for Dala's BatterySaver is here:

https://github.com/dalathegreat/Nissan-Leaf-BatterySaver
 
If charging on a 30+ amp L2 EVSE at 240 volts, figure about 6 kWh per hour is added to the battery during the full power phase, before ramp down and bounces. 6 kWh/h --> 6 kW, since h's cancel out. 6.0 kW is the official max OBC output while drawing 6.6 kW from the wall.

At my work, the supply voltage is ~208 volts, hence the typical max of 5.7 to ~6.1 kW or so (from the "wall") on our 30 amp L2 EVSEs.
 
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