E-Bike Battery Guide

Ravi Kempaiah

Well-Known Member
This thread is dedicated for helping new E-bike owners to understand and maintain their batteries in the best possible way.

There is a lot of confusion for any new E-bike owner as to how one should treat their batteries: Shop owners may say one thing, online resources may another thing, someone else says charge after every ride, dont worry! and few others say charge to 80%. It is painful to see so much misinformation floating around. So, you may ask why should I trust this information anymore than some random internet article. Nope, you don't have to trust me. The thread will have information that is thoroughly vetted by the scientific community and is widely accepted, not my personal opinion.

  1. I just got a new E-bike, how should I treat my battery?

    Awesome! Your eBike comes with a battery charger and give it a good look and make sure it is the right one.
    A 36V bike should have a charger that goes upto 42V or
    a 48V bike should have a charger that goes upto 54V.

    Most ebikes are shipped with batteries at 50% charge. Before your first ride, your shop should have charged it to 100%. If you bought it online, plug in your charger and charge it all the way. Once the charger reaches the 100% mark, it should turn green from red.


  2. What is the best practice for charging an E-bike battery?

    On your E-bike manual or your dealer who may not have the scientific background, may say, top it off after each ride. Yes and no. If you don't care about the longevity of the battery, just charge it after each ride, the high voltage cutoff (HVC) in the battery management system (BMS) shuts it off after it reaches 100% ( 42V for a 36V battery system or 54.5V for a 48V battery system). This practice may provide roughly 400-500 cycles before there is a substantial degradation in the cell chemistry. You simply don't have the mental bandwidth or interest in managing your battery and you are happy to replace the battery after 2 years, then you don't have to read any further.

    But, Li-ion batteries have infiltrated our lives (laptops, phones, tablets, cars). So, it can be good to know a bit more. Have you ever wondered why cellphone batteries or laptop batteries die quickly within a year or so. Plugging it in overnight is def one of the primary causes. Read on..

    What should I do?

    Charge your battery when it is not too cold or too hot. Let's say you just came back from a 50 mile ride and the battery is pretty warm ( you may not be able to feel it by touching the plastic case, but it does get warm). Leave it for 30 mins so it is back to the room temperature. Ideally, charge your batteries such that it does not sit fully charged for hours. So, if your morning commute starts at 7.30am, either charge your battery to 80% the night before or that early morning.

    You can double the cycle life of your battery by charging it only to 80%. Here is a neat infographic from Grin Tech in Canada, one of the innovators in the space.

    charge.png


    They even developed a smart charger for this purpose called "Cycle Satiator". Check this out: http://www.ebikes.ca/product-info/cycle-satiator.html

    I don't have a Cycle Satiator nor do I want to invest in one!

    That's perfectly fine. You can just use the charger that came with your bike (most generic 2A chargers are made by Modiary or Shenzhen in China). Try to the keep the state of charge (SOC) between 20% to 80% if possible and enjoy your bike.

    There are other cheaper options out there that do a similar job.
    36V charger ----- 48V charger ---- 52V charger.

    If you are interested in maximizing battery life, be mindful of these two parameters:

    High temperature = BAD for Li-ion cells. So what is high temperature? Anything above 40'C or 105'F (trunk of a car on a hot summer day or exposing battery direct sunlight in Arizona or running your eBike on full turbo or throttle. One can run his E-bike on full turbo if the cell chemistry is tuned for that (Samsung 30Q vs 35E).

    Time (days or weeks) spent at high voltage = BAD for Li-ion cells. You charged it 100% and you're going away for a long weekend. This may not be a good idea.

    Everyone in the electric vehicle space knows who Elon Musk is, so I am attaching a pic of his response to this question.

    1532193241061.png


  3. How to store your E-bike battery?

    It is best to store your battery at room temperature (cool, less humid conditions) and at 50% charge. If that's not possible, just avoid storing at 100%. I am attaching a scientific article on how calendar life ageing and conditions affect the degradation. Basically, What they are saying is degradation is minimal in the 30%-70% zone.

    "
    The storage initial SOC level is also one of the admitted factors of battery ageing during its calendar life. According to these studies [32,43], a high SOC level (>70%), or a low one (<30%), engenders a huge potential disequilibrium on the electrode/electrolyte interface and this accelerates chemical reactions. All through this experiment, the battery was under extreme SOC (>90% or <10%) quite often during each use session. However, most of storages happened during the fifth session (Table 3), and the SOC level is here considered at a critical low level (Fig. 7). This observation can also explain the ageing results of the fifth session.
    "

    The paper is attached below [Predicting battery degradation in EV's].

  4. What are some of the things that can damage an E-bike (Li-ion) battery?

    Here is a neat article: by Micah Toll who has written a book on how to build Li-ion batteries from cells.
    What causes Li-ion cells to die?

    https://electrek.co/2018/05/04/are-you-killing-your-lithium-batteries/ (the comments section has some interesting responses).

    Time spent at high charge ~100% charge is bad i.e., if you leave your charger plugged in overnight, expect ~500 cycles instead of 800+ cycles. It's perfectly ok to charge your battery to 100% but keeping the batteries at 100% for days may not be a good idea.

    A fantastic video by Prof. Jeff Dahn replete with scientific insights regarding battery degradation is here. Prof Dahn is world's foremost expert when it comes to Li-ion batteries. He invented the NMC chemistry and is the current Canada research chair heading Tesla's exclusive battery research program with a university.


  5. What kind of charger should I use?

    If possible, use chargers that charge at less than 8A (most chargers run at 2A or 4A, which are perfectly fine)

If it adds any credibility, I have been an E-biker for over 4 years and have had various level of exposure into this. I am also pursuing my doctoral work on Li-ion batteries at the University of Illinois.

The thread will have only vetted, scientifically verified data on how to treat your battery. Feel free to add your thoughts and questions that might enhance one's understanding on the topic, feel free to subscribe but please refrain from posting unrelated stuff.
 

Attachments

Last edited:

ebikemom

Administrator
Staff member
Wow, Ravi, great article!

I have four Pedego bikes--the batteries are VERY expensive, so doubling battery life sounds super appealing to me.

The cycle satiator looks great, but I only have 48V batteries, so don't need so many options. Thus, the Luna advanced charger looks like a terrific solution... but ...

My Pedego battery appears to have an XLR female input (here is a photo of the Pedego 48v charger's male connector--is this an XLR?). The Luna advanced charger (https://lunacycle.com/48v-3amp-luna-mini-charger/) appears an XT60 male output. So, it looks like I would need an xt60 male to XLR female adaptor cable to use the Luna charger with my Pedego battery. Do I have that right??? I'm getting dizzy looking at adapters and plugs, since I'm not an electrical person used to looking at such things, and I can't find an xt60 male to XLR male adaptor cable by googling ....

Thoughts?

Hmm, would this work?
The charger (This mini-charger also has a setting to charge to 80%): https://lunacycle.com/48v-3amp-luna-mini-charger/
To change the xt60 to XLR, but ... https://lunacycle.com/xlr-f-to-xt60-m-convertor/
maybe need this too to connect to the Pedego battery female connector? https://www.amazon.com/Male-CableCreation-5-PACK-Microphone-Adapter/dp/B01J2OSKVA/ref=sr_1_fkmr2_4?s=electronics&ie=UTF8&qid=1532358621&sr=8-4-fkmr2&keywords=xt60+to+xlr+adapter

Thanks!!!
 

Attachments

Last edited:

Bruce Arnold

Well-Known Member
@ebikemom It might be easier and less expensive to go a different route. Go to Amazon and get a cheap timer and multimeter. Go to this website and scroll down to "How to Check Pedego Battery at the Discharge Port" to see how to use the multimeter to check the voltage. This is all really simple; easier to do than to describe. A 48 volt battery reads at 51.5 volts at 80% charge. Experiment a little with the charger that came with your bike to find out how long it takes to get your battery to 80%. Then use the timer -- the one I linked has 15 minute divisions which is close enough, you might be a little over or a little under but with no practical consequences. 15 bucks and you're set up. You might find other uses for the timer and/or the multimeter too, so that's a bonus.
 

ebikemom

Administrator
Staff member
@ebikemom It might be easier and less expensive to go a different route. Go to Amazon and get a cheap timer and multimeter. Go to this website and scroll down to "How to Check Pedego Battery at the Discharge Port" to see how to use the multimeter to check the voltage. This is all really simple; easier to do than to describe. A 48 volt battery reads at 51.5 volts at 80% charge. Experiment a little with the charger that came with your bike to find out how long it takes to get your battery to 80%. Then use the timer -- the one I linked has 15 minute divisions which is close enough, you might be a little over or a little under but with no practical consequences. 15 bucks and you're set up. You might find other uses for the timer and/or the multimeter too, so that's a bonus.
I guess the challenge would be that how long it takes to get to 80%-ish would depend on how full the battery was to start?
 

Ravi Kempaiah

Well-Known Member
Hi @Alaskan , As a owner of 3 Bosch battery packs, I am yet to find a suitable, satiator-type charger for Bosch powerpacks. I have been using rough gestimates (stopping the charge when the 5th LED blinking) and my packs have sustained good amount of capacity even after 1.5 years. Until you or I find a better solution, that's what I am going to use.

@ebikemom , glad you found it useful. Pedego as a company is very responsive to any warranty claims but it is smart of you to be proactive and try to get max battery life out of your bikes. They have had their fair share of battery pack issues by using generic cells and battery design that resulted in a battery recall of 5000 packs.
https://www.cpsc.gov/Recalls/2015/pedego-recalls-electric-bicycle-batteries

Since then they have moved towards better designs and higher quality cells. I hope your dealer is a friendly one. Some dealers think you are being too anal about small details and they may not know the implications of charging to 100%. But, in the long run, your batteries will outlast other batteries on the field even after heavy use. But, I don't expect them to be experts at battery design. They still have this going.. https://www.pedegoelectricbikes.com/battery-details/#charge

Pedego.JPG

My Pedego battery appears to have an XLR female input (here is a photo of the Pedego 48v charger's male connector--is this an XLR?). The Luna advanced charger (https://lunacycle.com/48v-3amp-luna-mini-charger/) appears an XT60 male output. So, it looks like I would need an xt60 male to XLR female adaptor cable to use the Luna charger with my Pedego battery. Do I have that right??? I'm getting dizzy looking at adapters and plugs, since I'm not an electrical person used to looking at such things, and I can't find an xt60 male to XLR male adaptor cable by googling ....
You're right. That's a male XLR pin. @Mr. Coffee posted this image a while ago. You could get XT 60 to XLR-male pin connectors for a Luna charger.

Charger.JPG

You have already found the solution. Using a timer can be an inexpensive option but it does demand little bit of cognitive effort in terms of guessing the existing charge and time needed etc. Since you say you your use your bike quite a bit and you have 4 pedego bikes, it would be good to have a satiator and by default it comes with a male XLR plug. If you have the 48V, 15Ah battery then it would be a worthy investment for a household of 4 E-bikes because $300 amortized over 3-4 years for 4 batteries is quite cheap.
 

Bruce Arnold

Well-Known Member
I guess the challenge would be that how long it takes to get to 80%-ish would depend on how full the battery was to start?
Yes, that's true. If you always start charging from the same level, then it will always take about the same amount of time. A few percent of charge one way or the other isn't going to make a serious difference. My LCD display shows the battery voltage, so I could easily plan to recharge when it got down to, say, 46 volts. That's around 40-45 miles worth of riding for me, so like every two or three days depending on how much I'm on the bike.

I don't think the Pedego display shows voltage, but you could use the (rather inaccurate) "bars" display -- like charging when it drops to 2 bars remaining out of 5. Or maybe one bar -- it's hard to say what they mean. If you had a multimeter you could figure it out, though.

You could also go by feel. My bike starts getting less responsive between 46 and 44 volts, and sluggish below 44. 44 volts is right around 30% and 42 is around 20%. It's a really rough way of doing it but this isn't an exact science.
 

JRA

Well-Known Member
It helps to have an accurate reading of the ah’s used for timing purposes and the most precise instrument for that is a CA 3, also made by Grin. $120 or so option, so cheaper than a Satistor, and makes the timer deal less of a guessing game. Not to mention it’s many other features.

A simple watt meter in the power line will do it cheapest though but If you take off the battery during a use cycle and plug it back in it zeros out the ah’s but still reads the correct voltage.

0D2A7BFC-97B8-4B3E-B4FD-16EB837AA5B3.jpeg


Was just there today actually
 

hoit

New Member
Hi Ravi,

first of all thanks for taking the time to put this information together. eBike batteries are expensive and for me putting a little more rigour into my charging routine is worth the effort.

Ideally, charge your batteries such that it does not sit fully charged for hours
Yes, sitting at 100% charge for extended periods is bad. Personally, I don't think I would classify hours as an extended period.

It would be good to cover off balancing which is one case where you do want to take your battery to 100% charge to enable the cell balancing to occur.

Here is a neat infographic from Grin Tech in Canada,
Yes it's a neat infographic. It would great if Grin could provide the scientific data behind it.

BH also has a neat infographic showing "Maximum deterioration of 20% after 500 complete charge and discharge cycles" To me 80% capacity after 500 cycles is still pretty useful ...

Who do I believe in the absence of hard scientific data ?


And for those that found Prof Dahn just a little dry this video from EbikeSchool.com is a bit easier to watch
How To Double The Life Of Your Lithium Batteries
 

Ravi Kempaiah

Well-Known Member
BH also has a neat infographic showing "Maximum deterioration of 20% after 500 complete charge and discharge cycles" To me 80% capacity after 500 cycles is still pretty useful ...
Who do I believe in the absence of hard scientific data ?
BH has a battery diagnostic device that can tell you what's the SOH (state of health) and how many cycles are done. I recommend you do this if you think your battery is aging prematurely and your dealer should be able to get his hands on one. The problem is, degradation is not linear. Let's say your battery had 80% charge capacity left after 400 cycles and it will go exponentially down because of impedance build up. By 450 cycles, it may have only 50% SOH.

The reason why everyone on the Tesla forum uses 80% or 90% charge limit
[https://teslamotorsclub.com/tmc/threads/simple-question-better-to-charge-to-80-or-90.114991/

https://forums.tesla.com/forum/forums/charging-model-3-80-90-only,

https://forums.tesla.com/forum/forums/80-or-90]

is not because Elon Musk said so..

But, there is a strong body of scientific evidence to suggest that. I will just link a few papers not the hundreds but if you are interested, message me, I can share the folder of scientific papers relevant to this.

Effect of high temperature and how it accelerates parasitic reactions
  1. A comparative study of commercial lithium ion battery cycle life in electrical vehicle: Aging mechanism identification
  2. Calendar life performance of pouch lithium-ion cells.
  3. Calendar life study of Li-ion pouch cells.
  4. Cycle life estimation of lithium secondary battery by extrapolation method and accelerated aging test.
Effect of super low temperatures and how it affects the charge capacity
  1. Degradation mechanisms in Li‐ion batteries: a state‐of‐the‐art review
  2. Factors that affect cycle-life and possible degradation mechanisms of a Li-ion cell based on LiCoO2.
Effect of charging rate and overcharging on the capacity.

  1. Cycle life testing and modeling of graphite/LiCoO2 cells under different state of charge ranges.
  2. Incremental Capacity Analysis and Close-to-Equilibrium OCV Measurements to Quantify Capacity Fade in Commercial Rechargeable Lithium Batteries.
A detailed study reporting the effect of depth of discharge. Check this paper.

Online state of health estimation on NMC cells based on predictive analytics.

Depth of discharge - Journal of Power Sources 2016.jpg


To summarize:

Don't keep your battery at 100% all the time, don't expose it to hot temperatures and enjoy your ride.
 
Last edited:

Mikespike64

New Member
I apologize if this has been answered but I’ve read a LOT of info today and don’t think I’ve come across it-

I have a Voltbike Yukon 750 2018 with 48v 16ah battery. It comes with a 5 amp fast charger. I don’t want to drive myself nuts with this, but it seems that a faster charge equals less longevity.

Say I want to simplify things and not worry about timing and whether the battery is above 80% etc., and just want a charger I can plug it into at night. Would Voltbike’s or another standard 48v non-fast charger be better than the supplied fast charger for the long term life of the battery?
 

Ravi Kempaiah

Well-Known Member
I apologize if this has been answered but I’ve read a LOT of info today and don’t think I’ve come across it-

I have a Voltbike Yukon 750 2018 with 48v 16ah battery. It comes with a 5 amp fast charger. I don’t want to drive myself nuts with this, but it seems that a faster charge equals less longevity.

Say I want to simplify things and not worry about timing and whether the battery is above 80% etc., and just want a charger I can plug it into at night. Would Voltbike’s or another standard 48v non-fast charger be better than the supplied fast charger for the long term life of the battery?
Mike,
You say you have a 16Ah battery. Using a 5A charger equates to charging that battery in roughly ~ 3.5 hours. Which is less than < 0.3C and this is a safe range. If you had a 8Ah battery, then it would be different. Higher amp batteries need larger charging current.
Even if you use the slow 2A charger that charges your battery in 8 hours, it is not recommended to keep your battery plugged in overnight unless it was really low and you know you are going to use it the next morning. Theoretically, charging at 2A has slight benefit over charging at 5A but if you keep them plugged in then those benefits vanish.

This charger from Lunacycle would be a much better option as it comes with 80%, 90% and 100% option.
https://lunacycle.com/batteries/chargers/luna-charger-48v-advanced-300w-ebike-charger/

In summary, I would not worry too much and get caught up in this. Just don't leave your battery at 100% and you will get 500+ charge cycles.
 
Last edited:

Mikespike64

New Member
Mike,
You say you have a 16Ah charger. Using a 5A charger equates to charging that battery in roughly ~ 3.5 hours. Which is less than < 0.3C and this is a safe range. If you had a 8Ah battery, then it would be different. Higher amp batteries need larger charging current.
Even if you use the slow 2A charger that charges your battery in 8 hours, it is not recommended to keep your battery plugged in overnight unless it was really low and you know you are going to use it the next morning. Theoretically, charging at 2A has slight benefit over charging at 5A but if you keep them plugged in then those benefits vanish.

This charger from Lunacycle would be a much better option as it comes with 80%, 90% and 100% option.
https://lunacycle.com/batteries/chargers/luna-charger-48v-advanced-300w-ebike-charger/

In summary, I would not worry too much and get caught up in this. Just don't leave your battery at 100% and you will get 500+ charge cycles.

Thanks Ravi. I’ve seen in another thread where Thomas Jaszewski warned against that charger based on his experiences with his customers returning them. Someone in my Voltbike Facebook group said the charger adapter had issues in the past that might have been corrected since, any thoughts on that?

Also, a scenario I might have a lot would be going for a ride in the evening, plugging the bike in at around 9 pm, and then riding to work the next morning at 8. Would that still be too long to leave it plugged in regularly if I’m going to ride the following morning?
 

ebikemom

Administrator
Staff member
Also, a scenario I might have a lot would be going for a ride in the evening, plugging the bike in at around 9 pm, and then riding to work the next morning at 8. Would that still be too long to leave it plugged in regularly if I’m going to ride the following morning?
I just got a countdown timer. It turns off the power after a certain amount of time that you set, between 0-12 hours. Works great!
 

Thomas Jaszewski

Well-Known Member
Thanks Ravi. I’ve seen in another thread where Thomas Jaszewski warned against that charger based on his experiences with his customers returning them. Someone in my Voltbike Facebook group said the charger adapter had issues in the past that might have been corrected since, any thoughts on that?

Also, a scenario I might have a lot would be going for a ride in the evening, plugging the bike in at around 9 pm, and then riding to work the next morning at 8. Would that still be too long to leave it plugged in regularly if I’m going to ride the following morning?
The price of the charger with limited capability, and 1/3 of the Satiator price, covers only one battery level. Before doing CS I already had two bikes. A 36V and a 48V. That's $200 plus shipping for limited features and two voltages. Those chargers have no data collection and no safeguards at the same or even near the level of the Satiator. They may well have made improvement to the $100 chargers, but there's a reason for the short warranty periods on MANY resellers chargers. For years chargers have been one of eBikes dirty secrets. CHEAP and unreliable. I have two failed $100 chargers on my bench.
 

JRA

Well-Known Member
I also had a charger from the above mentioned vendor that failed. I took it apart and inspected it but couldn't find anything obvious. I put it back together and plugged it in and it now works. No idea what I did but I am not complaining now that it is working again....

Quite frankly I haven't invested in a Satiator personally because my battery cost is so low that to this point I have considered them to be dispensable items and get as much out of them as I can. I have 48v and 52v so chargers for both and quite often both at charge at the same time.

Especially in anticipation of the new 2170 cells and their ability to actually charge over 3A , as in up to 7A, it will be my go to unit when that battery finally is in stock. I predict the initial run of 2170 batteries will be on the expensive side so proper battery management will be desirable for a longer lifespan and the 7A charge good for those times when a quick fill is needed.
 

Thomas Jaszewski

Well-Known Member
I also had a charger from the above mentioned vendor that failed. I took it apart and inspected it but couldn't find anything obvious. I put it back together and plugged it in and it now works. No idea what I did but I am not complaining now that it is working again....

Quite frankly I haven't invested in a Satiator personally because my battery cost is so low that to this point I have considered them to be dispensable items and get as much out of them as I can. I have 48v and 52v so chargers for both and quite often both at charge at the same time.

Especially in anticipation of the new 2170 cells and their ability to actually charge over 3A , as in up to 7A, it will be my go to unit when that battery finally is in stock. I predict the initial run of 2170 batteries will be on the expensive side so proper battery management will be desirable for a longer lifespan and the 7A charge good for those times when a quick fill is needed.
It really depends on Ones situation, IMO, but having 4 different battery voltages and around 10 batteries, the Satiator in invaluable. Logging and history is useful as well.