[semenzato]

Hi,

I live near the top of a hill, and on the first trip down in the morning, the engine brake is only partially effective because the battery is full and apparently the car has no other place to put the recovered energy. It's a waste of energy, but especially a waste of brake pads.

Ideally I'd like to stop charging the battery when it's 90% or 95% full, and it seems that it would be a simple addition to the HondaLink UI. Other cars have that ability (my friend's Tesla 3 does, for instance).

If the HondaLink web interface worked, I could write a Chrome extension to do this automatically (by polling the battery status). But for some reason it doesn't:

Compatible with the following vehicles:
2018 - 2019 Odyssey Touring/Elite
2018 Accord Touring
2019 Insight Touring
2019 Pilot Touring/Elite

I don't think that there an equivalent way of doing this through the phone app. (Reverse-engineering the protocol is too much work.)

Can we pester Honda to fix this? Not that it will work---they seem to have pretty weak software resources.

Thanks!

 

[firsthonda]

The may not be the best way to do what you want but it is the easiest way I car think of.
If you leave your house @ 7 AM you can use the phone app to begin charging at 6 AM or maybe start charging @ 5:30 AM. You will have to experiment with start times until you figure out who you want the charging to begin. You will have to adjust the start time based on how much remaining charge you had when you began charging.

 

[semenzato]

Thank you for the suggestion! It is a possibility, but I am not sure it is practical. I could produce a table that shows the start time based on the battery level at the end of the day, but it's still too much fiddling. Also, the garage is not heated, and the temperature might impact charge time so it's not clear that the table would be precise. But it still may be worth it...

 

[firsthonda]

Assuming that you have a level 2 charger like I do. ifI had 50% remaining I may want to set the charger to start 1 hour before I leave, but if I only have 25% remaining I might want to start charging 1 and 1/2 hours before I leave. But as I said you will need to experiment.

 

[pqdad]

Guess you have to just do it by time then, guesstimating how much time it will take to charge based on previous times you have charged (and of course how much charge you have at the start). I also would like to see that simple change. In fact I have heard that it is best (for LONG term lifetime) for the battery if you keep the charge between 20 and 80%, but of course this really depends on a lot of factors...

 

[firsthonda]

Guess you have to just do it by time then, guesstimating how much time it will take to charge based on previous times you have charged (and of course how much charge you have at the start). I also would like to see that simple change. In fact I have heard that it is best (for LONG term lifetime) for the battery if you keep the charge between 20 and 80%, but of course this really depends on a lot of factors...

Are you sure the the Honda does not charge to 100%? I owned a Volt and Chevy was designed not to charge to 100% How can you be sure that the Honda is not set the same way? Remember that just because the dashboard gauge says 100% it does not mean the Honda Battery is charged to 100%.The Volt gauge was set up to display it was 100% full but in reality the battery only charged 80% to protect the battery, it was also set to display that it was at 0% charge but the battery was really at 20 or 30% charge remaining. I would be willing to bet the Honda uses a similar protection system to prevent the battery dropping to 0% or it probably also displays a full charge when the battery is at 80% charge. I have no doubt that Honda took all this into consideration when the design the charging system.

I suggest you charge to 100% without worrying about harming the battery because Honda designed their batteries to last many years

 

[Cruiter]

How to control the amount of charge

For those wanting to charge to less than 100%, use the app for your phone. Using that, you can select for it to stop when "charging is full" or at a specific time. I select for mine to start charging at 11PM because with the GA Power plan I'm on, the kilowatt per hour charge goes down dramatically at 11PM. I just let it go to full, but you can select for it to stop say at 12 PM or whenever you want. I see no harm in that as Honda provided it to work that way and suggests it's use.

BTW, to encourage everyone to 'read' their manuals, I won't say on what page to look, but online you can find info on the battery warranty that exceeds everything else on the car if you use as directed. It's really loooooong LOL.

On this site http://techinfo.honda.com/rjanisis/pubs/OM/AH/ATRW1818OM/enu/ATRW1818OM.PDF

you can find the Clarity owners manual. Loving my Clarity, cash ownership w/o a lease and may own this car for many years. I'm a certified car nut and have owned north of 200 new and used cars lifetime but this could be the last unless or until Honda builds a Plug in Hybrid SUV (my preference style and size).
Happy driving and charging :grin:

Are you sure the the Honda does not charge to 100%? I owned a Volt and Chevy was designed not to charge to 100% How can you be sure that the Honda is not set the same way? Remember that just because the dashboard gauge says 100% it does not mean the Honda Battery is charged to 100%.The Volt gauge was set up to display it was 100% full but in reality the battery only charged 80% to protect the battery, it was also set to display that it was at 0% charge but the battery was really at 20 or 30% charge remaining. I would be willing to bet the Honda uses a similar protection system to prevent the battery dropping to 0% or it probably also displays a full charge when the battery is at 80% charge. I have no doubt that Honda took all this into consideration when the design the charging system.

I suggest you charge to 100% without worrying about harming the battery because Honda designed their batteries to last many years

 

[tom]

Oh man. Too bad you don't live at the bottom of the hill
For me, I live 1/2 way up a hill, and when I have a reasonable choice, I drive up the hill when fully charged.

 

[Claire Greene]

Are you sure the the Honda does not charge to 100%? I owned a Volt and Chevy was designed not to charge to 100% How can you be sure that the Honda is not set the same way? Remember that just because the dashboard gauge says 100% it does not mean the Honda Battery is charged to 100%.The Volt gauge was set up to display it was 100% full but in reality the battery only charged 80% to protect the battery, it was also set to display that it was at 0% charge but the battery was really at 20 or 30% charge remaining. I would be willing to bet the Honda uses a similar protection system to prevent the battery dropping to 0% or it probably also displays a full charge when the battery is at 80% charge. I have no doubt that Honda took all this into consideration when the design the charging system.

I suggest you charge to 100% without worrying about harming the battery because Honda designed their batteries to last many years

Honda has the same system to protect the lithium ion batteries. When depleted our gauge shows 2 bars but when full it shows 100% charge even though it does not charge to 100% to protect battery. My suggestion is to use the ac or heater first thing in the morning, maybe the defroster for a few minutes, move your power seat couple times, listen to radio or turn on seat heater if you have it, you know, use some of that battery charge to make room for regen and save your brake pads.This will also keep the ICE from running and wasting gas. Apparently part of the battery overcharge protection is to run the engine to act as a load and bleed off any regen charge when battery is full.

 

[longfam18]

What about coasting down the hill in neutral? If your only worry is wasting brake pads then that should solve the issue.