Optimal battery % charge

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

preilly44

***
Joined
Dec 28, 2014
Messages
73
Does anybody know what the best % to charge your battery to on a daily basis? I understand Tesla is 80-90%.

Also, should I charge daily to top it off to 80/90% or only charge it when it's needed?

Thanks in advance!
 
Lithium batteries in general like to be just under 50% charged - about 45%. But the curve is fairly flat from 20% - 80%, with little difference in this range. This is why many EVs give you the option to charge to 80%. The Volt always keeps its battery in this range. Of course, it can afford to, since it also has a gas engine.

All you ever wanted to know about batteries (and more) can be found here:
http://batteryuniversity.com/

Unfortunately, the EPA reports an EV's range as the average of the charge settings, so some EVs have done away with the 80% option. This way, the range on the sticker is higher.
 
I have concluded there is no way to pre-set a limit of say 80% for a charge. Once you start charging, it will do a full charge unless you manually intervene and stop the charge, either by clicking the stop charge button on the car, removing the charging cable, or telling car net to stop charging.

If the objective for battery life/retain capacity is to try to keep the charge between say 30% and 80%, there appears no way to do it except by the clumsy method of constantly checking car net for the state of charge and stopping it when it shows 80%. The slider setting which I thought had something to do with it just tells carnet not to let the battery drop below the slider setting, but I can't see any use for this.

Both the vehicle and Car-net should have a charge % setting one can pre-set to stop charging at 80%. Of course, this could be over ridden if one were planning a long trip for the next day where 100% would be desired.

Ron
 
There is a way to limit it with the Car-Net app:
Go to e-manager > Departure Time and tap the gear icon in the top corner. This brings up a slider that limits the maximum charge globally, whether or not you use the scheduler to have the car ready at a certain time.
I was running mine at 80% max, but bumped it back up to 100% when I needed to do extra distance the other day and I noticed the difference in the full charge range estimate. I might leave it at 100% as it's a lease car ;)
 
cove3 said:
The slider setting which I thought had something to do with it just tells carnet not to let the battery drop below the slider setting, but I can't see any use for this.

It seems both the vehicle and Car-net should have a charge % setting one can pre-set to stop charging at 80%. Of course, this could be over ridden if one were planning a long trip for the next day where 100% would be desired.

Ron
Ron,
I think that's a typo in the Car-Net app. Although it says over the slider 'minimum battery charge level', below it the text says ' The system will charge to this level when the charging plug is connected'
 
cove3 said:
I have concluded there is no way to pre-set a limit of say 80% for a charge. Once you start charging, it will do a full charge unless you manually intervene and stop the charge, either by clicking the stop charge button on the car, removing the charging cable, or telling car net to stop charging.

If the objective for battery life/retain capacity is to try to keep the charge between say 30% and 80%, there appears no way to do it except by the clumsy method of constantly checking car net for the state of charge and stopping it when it shows 80%. The slider setting which I thought had something to do with it just tells carnet not to let the battery drop below the slider setting, but I can't see any use for this.

Both the vehicle and Car-net should have a charge % setting one can pre-set to stop charging at 80%. Of course, this could be over ridden if one were planning a long trip for the next day where 100% would be desired.

Ron

You can indeed use Car-Net to make your car charge to 80%. Just use a delayed (departure time) schedule. Set a charging profile (called charging location in the app) to what you want charging to stop at, and setup a charging schedule (called departure time in the app) that uses that profile/location and a departure time within 2 hours after you typically plug it in each day.

Make sure when you plug it in, the bottom button (with the clock icon on it) in the charge port is lit. Unless the car already has a higher SOC than you set in your profile/location, or you set a departure time far enough ahead that it would take less time to charge to your set level than that window of time, it should start charging right away. Otherwise it should start charging when it can reach the target SOC by the departure time.
 
Back
Top