Li-Ion Battery % Charged Charts

[Smaug]

<edit> Anton chimed in, and rather than duplicated everything here, I'll just provide links to where he has posted the tables in the reference section.

• 36 V (10S) Charge percentage table: https://ebikesforum.com/resources/36-volt-10s-battery-voltage-chart-li-ion-batteries.38/
• 48 V (13S) Charge percentage table: https://ebikesforum.com/resources/48-volt-13s-battery-voltage-chart-li-ion-batteries.37/
• 52 V (14S) Charge percentage table: https://ebikesforum.com/resources/52-volt-14s-battery-voltage-chart-li-ion-batteries.39/
• 60 V (16S) Charge percentage table: https://ebikesforum.com/resources/60-volt-16s-battery-voltage-chart-li-ion-batteries.40/
• 60 V (17S) Charge percentage table: https://ebikesforum.com/resources/60-volt-17s-battery-voltage-chart-li-ion-batteries.50/
• 72 V (20S) Charge percentage table: https://ebikesforum.com/resources/72-volt-20s-battery-voltage-chart-li-ion-batteries.41/

<snip old table></edit>

Typically, we should keep the batteries between 20-80% state of charge for a longer life.
Feel free to charge to 100% if you'll use the battery within the next couple days.
Try to avoid discharging below 20%. (42.1 V)
Long-term storage voltage should be around 50% charged.

@Anton , I think you had charts like this somewhere, but I can't find them now. I thought it would be handy to have them in a sticky post here.

 

[BiggKidd]

So far my battery hasn't made it below 43V and hopefully it never will!

My preferences are anything over
53V = full
48V = half
43V = dead

I know I'm leaving power but treating batteries this way has served me well for 40 years long before Li types and since. With lead acid deep cycle batteries I usually kept the discharge to 25-30% or 70-75% still available and I usually got over 12 years of service out of them.

 

[Glenn Goodlett]

I never know what to make of these charts... I mean is that the resting voltage, voltage under load, resting after 10 seconds, resting after 5 minutes, etc. My batteries always seem to creep back into the 90% or higher range after a 35-mile ride and I know they don't have 90% capacity remaining.

 

[munirider]

Thanks, yeah this is the same chart that m@ had on his website tales on two wheels he also had on for 52V and 72V I just had a bookmark and unfortunately I never downloaded or printed them. I have seen them elsewhere here's the same chart 52V

I just posted the link I didn't expect it to post the chart itself so I don't think I violated any copyrights.

 

[munirider]

I never know what to make of these charts... I mean is that the resting voltage, voltage under load, resting after 10 seconds, resting after 5 minutes, etc. My batteries always seem to creep back into the 90% or higher range after a 35-mile ride and I know they don't have 90% capacity remaining.

Yeah it just gives you a ballpark idea of where you are at, I have always assumed it is at a state of rest not under load but it seem that it's like the gas gauge in your car there's always more gas in the first half than there is in the last half.

 

[BiggKidd]

I never know what to make of these charts... I mean is that the resting voltage, voltage under load, resting after 10 seconds, resting after 5 minutes, etc. My batteries always seem to creep back into the 90% or higher range after a 35-mile ride and I know they don't have 90% capacity remaining.

Great question, the voltage a few seconds to a minute after stopping use is a good time to judge and I prefer the number as soon as I switch the display to read, if it were already on screen I'd say wait 5-10 seconds. That number is more honest than the creep back up number feature of many Li types. I'd rather get home with excess battery than not make it home! I've ridden my 23AH 48V battery 46 miles on a single charge and still had a few more miles before dead (@43V) when I got home. My bike is both big and heavy with dual 1000 watt motors, the above was done with lots of pedaling along with the motor at 13mph.

 

[munirider]

Huh, I found the 48V chart here on the forum doing a internet search, https://ebikesforum.com/media/48-volt-nominal-voltage-chart-for-ebike-batteries-jpg.297/

 

[Anton]

@Anton , I think you had charts like this somewhere, but I can't find them now. I thought it would be handy to have them in a sticky post here.

The charts I made up are all in the Resources section over here: https://ebikesforum.com/resources/categories/ebike-general-information.11/

 

[Smaug]

The charts I made up are all in the Resources section over here: https://ebikesforum.com/resources/categories/ebike-general-information.11/

Thanks. I edited the first post to just link to those.

 

[Smaug]

Great question, the voltage a few seconds to a minute after stopping use is a good time to judge and I prefer the number as soon as I switch the display to read, if it were already on screen I'd say wait 5-10 seconds. That number is more honest than the creep back up number feature of many Li types. I'd rather get home with excess battery than not make it home! I've ridden my 23AH 48V battery 46 miles on a single charge and still had a few more miles before dead (@43V) when I got home. My bike is both big and heavy with dual 1000 watt motors, the above was done with lots of pedaling along with the motor at 13mph.

It takes more than a few seconds to stabilize, as it takes awhile for the voltage to creep back up as the battery cells cool off. I feel like 1-5 minutes is better. You'll find that when you come back and check it again an hour or two later in the garage, it's even higher.

However, it's safe to go by the voltage as soon as you stop using throttle, as that will be "worst-case" on the conservative side.

I have a voltmeter on the display of my Lectric XP Lite, and when I'm done using power, I can see it going up 1/10 of a Volt at a time over 30 seconds or so. The hotter the day, the longer it will take to cool off and bounce up to its top value.

 

[Tom3holer]

I am confused; yes it does happen the older I get.
On one chart it shows, for a 48v battery, 100% is 54.6 V, on another 100% is 53v
Being new here and trying to learn as much as I can. Thank you all for all the knowledge here.
Tom

 

[BiggKidd]

I am confused; yes it does happen the older I get.
On one chart it shows, for a 48v battery, 100% is 54.6 V, on another 100% is 53v
Being new here and trying to learn as much as I can. Thank you all for all the knowledge here.
Tom

54.6V is the maximum 53V to 54.6 is sort of a surface charge where there aren't really any appreciable amps / watts. I guess it's semantics.

 

[Bc2025]

Thanks for that chart Anton - I was curious how to properly maintain my batteries and the minimum charge level the battery should deplete to

They are not cheap to replace

 

[Bc2025]

One question I have for all of you as a point of clarification… I purchased a 2nd battery for my bike a few weeks ago and it came fully charged

We haven’t used it yet and may not until spring … should I deplete it some by riding with it as opposed to leaving it at 100%? If I read correctly, storing a battery for a long while at 100% is not something you recommend

 

[BiggKidd]

One question I have for all of you as a point of clarification… I purchased a 2nd battery for my bike a few weeks ago and it came fully charged

We haven’t used it yet and may not until spring … should I deplete it some by riding with it as opposed to leaving it at 100%? If I read correctly, storing a battery for a long while at 100% is not something you recommend

Most folks suggest leaving them below 80% and above 30% for any length of time. Personally I just don't know!

 

[Bc2025]

I’ll use that as a use of thumb Kidd - in any event, I shouldn’t store it at 100% is what I am hearing

 

[usclassic]

It is interesting my voltage showed 49.2 on the screen after about an 8 mile grocery run yet all the battery bars on the Aipas M1 were still lit.

 

[BiggKidd]

It is interesting my voltage showed 49.2 on the screen after about an 8 mile grocery run yet all the battery bars on the Aipas M1 were still lit.

The battery bars are notoriously off voltage is more trustable, still not perfect though.

 

[usclassic]

I just checked after fully charged and unplugged the M1 screen showed 54.2 V

 

[BiggKidd]

I just checked after fully charged and unplugged the M1 screen showed 54.2 V

Check it in the morning and see if it still is.