Stopping charge at 80%

Looking at the above video, here, it seems that the 80% charge setting in the App is only for advance route-planning for long trips so the App knows how much you intend to charge at each charger along the way so the App's trip planning will find the next charger close enough. It does not appear that setting actually controls how much the Ariya will charge. Looking through the Ariya Owner's manual previously posted it certainly looks like there is no 80% charge setting.

I got my 2016 Nissan Leaf at the end of 2015 and was most frustrated that it did not have a setting to stop charging at 80% (as it does so little regen-braking above that, so I would not get much regen benefit for all the short errands that are most of my driving).

I was also frustrated at how long it took for the App to update the charge status or start the A/C, especially when I knew that the car was so close to me that I should not need to wait for some slow Nissan server far away on the Internet to do this.

So I figured it would be a useful project solve all of this. I spent much time reading on-line forums that were reverse-engineering the Leaf's CAN-bus protocol (and I contributed to this by finding the code that would unlock all doors). I built and programmed this box below which plugged-in to the Leaf's OBD-II port and used Wi-Fi to communicate to a second box that was in my home office.


This second box has a touch-screen and colour display (below) to give me just the most important information and let me; quickly start the A/C, show whether the A/C is on, show the charging current and duration and change in charge, and toggle between whether to charge to 80% or 100%. And most importantly, when the charge reaches 80% it sends a Wi-Fi command to my EVSE to stop charging (as there appears to be no OBD-II command to stop the Leaf charging). And this all worked, and it was very quick as the Wi-Fi communicates directly with the car, with no waiting for Nissan's App and servers.


While this all worked, it was not reliable, maybe it was the three Wi-Fi connections needed (between the car, second unit, and EVSE), maybe it was trying to continuously communicate over the OBD-II port which is intended only for diagnostics.

So I instead did something much simpler and which has been more reliable; I programmed my EVSE to only charge for 90 minutes overnight and I only plug in the Leaf when the charge is below 60% or so and the next day the charge is enough for they day's errands but low enough to get good regen braking.

When I have a longer trip I do need to manually override the 90-minute charge. And when I forget to unplug the Leaf and don't drive one day, it does charge to 100%.

So this is a big disappointment that Nissan still won't provide the built-in 80% charge limit. The rumour at the time was that Nissan had to get rid of the 80% limit as too many range tests (government, magazines ...) would only take the vehicle range with an 80% charge so the car's range would not look good on comparison charts. So some other cars instead called this 80% limit "hill-top mode" (or some similar work-around) as if you lived at the top of a big hill you'd only want 80% charge so you could still get regen to start your day coasting down the hill.

For those wanting to see the 2023 Ariya manual, here is the link:


But I looked through it to see if, per chance, there WOULD BE an option to turn off charging at 80% ... but could find nothing. So, it would appear that Ariya owners who want the option charging only to 80% overnight may have to do some trial-and-error charging; that is, keep a log (spreadsheet?) of various battery charges the car had when plugged in, set the Ariya to charge starting at some pre-determined overnight time before one gets up, then see how much the car has charged in those hours. After several trials, one should be able to get enough data to produce a PRINTABLE SCALE that helps one determine "If my car currently has an XX% charge, set the EVSE to start charging at YY:ZZ time." (Assumes an overnight charge to save electrical costs). And, if you get up at the same time each morning, you'll eventually know how to charge to 80% each evening. SOUNDS COMPLICATED ... and it is! But if the Ariya's batteries—like it's been said of past Li-ion batteries—reduce their lifespan when charging too many times to 100%, I for one am going to try this brute-force, trial-and-error process so that I CAN charge only to 80%when desired. (I am retired and will be doing mostly around-town driving so don't ned to start my travels at 100% charge.)

Yes, here's one more anticipating-my-Ariya owner who thinks Nisan dropped the ball by not allowing an pre-determined shut-off option in the Ariya's charging software/firmware/controls.