Battery charging

Mkj

New Member
How often should you charge the battery on your electric bike? Every day??

I have a Giant energypak 400 - 36V lithium ion battery

I
 

antboy

Member
It really depends on how much you use it.

For extended storage (more than a few weeks), it's best to charge it to about 60-80%, but frequent use is a different story.

There's a bunch of info on the forum about this, and this article a good starter as well.


 

AlanDB

Well-Known Member
I think it is great to follow the charging recommendations for extending the life of your battery. That said, don't let "battery anxiety" spoil your ebike riding enjoyment. I know there are special chargers you can use to control the charging cycle to 80% or whatever. but I have 4 ebike batteries of 3 different types, voltages, connectors, etc., and sometimes just making sure they are all sufficiently charged up when we are ready to go for a ride is my most important consideration. If I shorten their life a few months by charging up to 100%, then so be it. I certainly don't leave them sitting on the charger for days at a time once they are fully charged, and I bring them inside to avoid extreme temperatures, but I don't lose any sleep over giving them a full charge so they are ready to go when I need them. That is just my strategy … YMMV.
 

AHicks

Well-Known Member
I second the thought regarding "battery anxiety".

I would suggest you learn enough about the technology so you aren't abusing your battery (running it until it won't go any further, or storing while totally discharged for example), but then just go use it!
 

The duke

Active Member
Charge it as much as you need to to use it but try not doing any more than that. Best to charge right before you ride instead of as soon as you use up a charge, so the battery sits full for as short a period as possible. If you don't need to charge in between rides, then don't. A battery that sits at 50% charge for most of the time will last twice as long as one that sits in the garage fully charged.

Buy a countdown timer. There are better, but this one costs just a few bucks, and when you know your battery and how long it takes to get a full charge, you can easily program this to stop charging when the battery reaches 80 or 90%. Simple steps can turn the need for an annual battery replacement into every 3 or 4 years.
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Mkj

New Member
Thanks for the advice I use my bike Monday to Friday to get to work,about 60 miles per week (roughly 12 miles per day) I'm still not sure how much to charge it even after reading the article posted by antboy.

Maybe I should let the battery run down??
 

rich c

Well-Known Member
Thanks for the advice I use my bike Monday to Friday to get to work,about 60 miles per week (roughly 12 miles per day) I'm still not sure how much to charge it even after reading the article posted by antboy.

Maybe I should let the battery run down??
I mostly ride Haibike with Bosch system. I charge based on anticipated riding. Need the distance, and it’s only down 20%, I fully charge. If the battery is at 40% and I’ll only ride 10 miles, I don’t charge. My 3 year old 400wh battery has always been charged to 100%. Still performs to my satisfaction, no idea what kind of loss of performance, but easily gets me 25 miles. Way more than enough for a full suspension eMtb.
 

Mtl_Biker

Active Member
Charge it as much as you need to to use it but try not doing any more than that. Best to charge right before you ride instead of as soon as you use up a charge, so the battery sits full for as short a period as possible. If you don't need to charge in between rides, then don't. A battery that sits at 50% charge for most of the time will last twice as long as one that sits in the garage fully charged.

Buy a countdown timer. There are better, but this one costs just a few bucks, and when you know your battery and how long it takes to get a full charge, you can easily program this to stop charging when the battery reaches 80 or 90%. Simple steps can turn the need for an annual battery replacement into every 3 or 4 years.
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You have a link to that timer? Looks pretty useful.

EDIT: Just found it on Amazon Canada... $23 with free shipping, but it says "Usually ships within 1 to 3 months". Crazy!

(I'm currently using Siri to set a count-down timer to alert me when I should unplug the charger. But I am sometimes occupied with something else and don't get around to unplugging right away.)
 
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6zfshdb

Well-Known Member
Keep in mind that lithium batteries rarely fail completely unless severely abused. We use the term "fail" to mean diminished capacity. This happens normally with age & use. Over time, charging to and storing at less than 100% will certainly delay this loss of capacity. However, a battery that has lost half it's original capacity is still usable. You just won't get the range you did when it was new.

I look at it this way. 80% of the rides I do require less than a full charge. I mostly run out of time & trail, or my butt gets too sore before the battery exhausts. I frequently return from a 30 - 40 mile ride with 20% or more charge left. That means I can afford to lose 20% of my batteries capacity and still ride normally most of the time. For those extended 50+ mile trips, I simply carry a spare.

Everyone rides differently and I realize my scenario won't work for all. This is especially true if you're on a budget and can't afford a spare battery.
 

The duke

Active Member
You have a link to that timer? Looks pretty useful.

EDIT: Just found it on Amazon Canada... $23 with free shipping, but it says "Usually ships within 1 to 3 months". Crazy!

(I'm currently using Siri to set a count-down timer to alert me when I should unplug the charger. But I am sometimes occupied with something else and don't get around to unplugging right away.)
Just use one of the auto off/on lamp timers you can buy at any Walmart or Walgreens equivalent. You shouldn't spend more than $5 on one of those and they should be everywhere.

I quickly learned that my battery charges 25% in 1 hour. That makes the math really easy to get to about 85% on each charge using the timer. I've found my ebike charges pretty evenly over time.

I'm doing the same thing with my other li-ion devices. Hopefully I'm extending all their lives.
 

antboy

Member
Yeah, I don't really have battery anxiety either, just wanted to share the info.

Thanks for the advice I use my bike Monday to Friday to get to work,about 60 miles per week (roughly 12 miles per day) I'm still not sure how much to charge it even after reading the article posted by antboy.

Maybe I should let the battery run down??
Like everyone else said, don't let "battery anxiety" get to you. Given that it's a pretty short commute, you could probably just charge it to 80% every night, and have juice to spare even if you forget to charge one or two nights.


As for letting it run down, I can't speak for other motors, but I know once I hit around the 25-30% mark on my rear hub Bafang, I start to feel the voltage drop (the motor just doesn't have the same oomph).