Do's and Don'ts for e-bike battery care. What do you do to keep your battery performing at its best?

Binhill1

🍊 Tango Man 🍊
Mar 7, 2019
3,258
5,048
Scotland
Yeah that would bother me tbh. I've heard of people knocking up DIY solutions to discharging batteries with fans and bulbs and things, be nice if there was an official plug and play device that did it but even better if the energy could be used for something useful like light or heat.
Someone will do something it has to be a common problem. I got ten metres from my house when the first motor went caput so couple weeks waiting for new one with full battery.
 

RipGroove

Active member
Jun 3, 2022
375
188
Glos/UK
Someone will do something it has to be a common problem. I got ten metres from my house when the first motor went caput so couple weeks waiting for new one with full battery.
I'm not sure if enough people realise you shouldn't leave them at full charge for it to become a mainstream issue that needs solving.
 
Fully charging the battery in anticipation of a long ride that gets canceled, and then having the battery sit at 100% for some time, is definitely something I'd try to avoid! :LOL:

Some "safe" ways to partially discharge the battery to a storage charge level in my opinion:
  • Go ride around the block in Turbo mode for 30 min or so. You can increase resistance by riding against the wind, or carrying a heavy payload! 💪
  • Remove the battery from the bike and ask a friend with a similar bike setup to go ride with your battery.
  • Put the bike on a workstand (or lift the rear wheel off the ground), and keep pressing on the Walk Assist button with a clamp. This could take many hours though!
  • With a Bosch battery, ask your LBS/Bosch dealer to use the discharge function on a bosch BCT (Battery Capacity Tester) to safely discharge the battery.
I would not suggest wiring a makeshift resistance to a Bosch battery to act as a discharge load, not knowning the connector pinout or BMS behavior. There is a risk of damaging the battery or become hazardous if you connect the wrong terminals!
 
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adam89pl

New Member
Aug 28, 2023
10
7
Poland
The worst thing you can do to a li-ion battery is storing it fully charged. I charge my bike at night before ride. After ride if it's discharged to less tha 30% I charge it to ~60%. After first 1500 km (10 months) battery is like new. I can make 60-75 km 1500-1650m. I'm 78 kg, bike Spectral On 720 Wh, mix eco and trail. Never tried 100% eco.
 

Tooks

Well-known member
Subscriber
Mar 29, 2020
480
576
Lincs UK
Age and using a battery will degrade it, same as us people.

Leaving it stored in a discharged state will kill it for sure.

Battery Management Systems are getting better all the time, they manage the battery so we don’t have to, you can’t overcharge a battery or discharge to absolute zero in use.

Most batteries should still be working just fine, even if they’ve lost a little capacity, for the useful life of the bike.

I think we should ride more and worry less! Worse case scenario, a replacement battery is about the same price as a good set of forks, and we don’t seem to complain about replacing those too much, even when we don’t need to!
 
Thanks @adam89pl for sharing your charging practices! (y)

While leaving the battery fully charged over time (in storage for example) can degrade the cells, keeping the battery in a deep discharged state will actually do irreversible damage to the cells up to the point that the battery is no longer usable and will need to be replaced.
 
I think @Alexbn921 and @RipGroove brought up a good point about letting the battery cool off after a ride before recharging it.

From my end, I also let the battery cool down a bit (for 1 hr or so) if I recharge it right before going for a ride. ;)

Really appreciate everyone's feedback on the topic. Went ahead and updated the "suggested charging best practices" post I started earlier. Latest version below. Comments always welcome!


Updated link
 
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While lithium-ion batteries naturally degrade (or age) over time, finding the root causes of abnormal battery degradations or failure is not trivial due to the sheer complexity of battery technologies and the many factors affecting battery lifespan and condition.

We know by now that battery health issues can often be linked to battery care and maintenance. But is the degradation happening gradually over the life of the battery, or quickly and unexpectedly? What are early signs and causes of accelerated battery wear, which could lead to battery failure and require a costly battery replacement?

Interested in this topic, I've gathered a list of common battery problems along with potential causes (and remedies) which have helped me so far. Here it is.

🆕SUGGESTED E-BIKE BATTERY CARE AND TROUBLESHOOTING TIPS

COMMON BATTERY ISSUES
  • Battery doesn’t take you as far as it did when it was new.
  • Battery health % or capacity is decreasing abnormally and battery feels like it's draining faster.
  • Battery doesn’t charge as fast as it did when it was new, or cannot be fully charged.
  • Battery is not holding or maintaining its charge.
  • Battery generates error codes on the bike's display or controller.
  • Blinking LEDs (or no lights at all) on the battery pack.

TIP #1 - CHECKING BATTERY HEALTH

I would check the health of the battery by measuring its voltage over time and inspecting the battery temperature.

To do that with my Bosch-powered bikes, I would have my LBS periodically run a full motor and battery diagnostic report to gather state of health or capacity, voltage, min and max temps. Some dealers use a BCT (Battery Capacity Tester) tool to assess battery health.

I would keep a history of the measurements collected over time, starting when the bike/battery was new for comparative analysis and early detection of any abnormal degradations.

TIP #2 - FINDING DEGRADATION CAUSES

If battery health % or capacity measured seem lower than expected, I would try to identify the causes or culprits of an accelerated (abnormal) degradation and then make corrective actions.

I would try to assess the severity of the degradation and determine if the battery is failing (and may need to be replaced) or if I just need to improve how I take care of my battery going forward. See best practices and tips for battery care here.

Keep in mind though that a 5 to 10% capacity loss over 3 years, or a 10 to 20% capacity loss over 6 years when given proper care, could be considered 'normal'. Refer to your battery warranty conditions to find out the capacity guaranteed by the manufacturer over a given number of years.

I've outlined below some of the major degradation causes for batteries, sorted by severity (from more to less severe):
  • Time spent at very low state of charge. Has the battery been over-discharged (10% or less) while in use or left discharged in storage for an extended time period? Has the battery often been recharged from very low charge levels, basically running the battery nearly empty on most rides?

  • Time spent in very low temperatures. Has the battery been charged, discharged (ridden) or stored at low temperatures below 0°C (32°F)?

  • Time spent in high temperatures. Has the battery been charged, discharged (ridden) or stored above 35°C (95°F) heat?

  • Time spent at very high state of charge. Has the battery been left fully charged (100%) for a long period of time?

  • Number of charging cycles. Has the battery reached or exceeded the max number of useful charge cycles per the manufacturer warranty limit? See here.

  • High charging current. Has the battery often been charged using a fast charger (6A-10A) rather than a 2A or 4A charger?

  • High discharging current. Has the bike been ridden with the highest motor assistance most of the time e.g in Turbo mode all the time?

  • Battery age/cell aging. How old is the battery? Find the age of your Bosch battery here. Has the battery exceeded the number of years under warranty? See here. Was the battery left on the shelves for several years before getting sold to the customer or being fitted in the bike?

TIP #3 - READING BATTERY ERROR CODES AND FLASHING LEDS

Understanding the error code shown on the bike display or the blinking lights on the battery itself is critical for troubleshooting battery issues.

If the ebike shows a battery-related error code on the bike display/controller, or if I notice flashing LED lights on the battery pack, I would check the battery manufacturer's Customer Support or Help Center site to find details about the error, what could be causing it, and what corrective actions I should take.

As an example, here is a link to the Bosch support site where you can search a specific error code and find details about it. Each manufacturer offers a similar service.
I've listed below common battery-related error codes and LED flash codes for the Bosch CX Gen 4 non-smart motorization.

ERROR CODES - Bosch battery
  • Error 423 Battery pack connection problem. Check electrical connections and clean contacts.

  • Error 540 Battery pack error. Switch off the ebike, remove the battery pack and then reinsert it. Restart the ebike.

  • Error 602 Battery pack error while charging. Unplug the charger from the battery pack. Restart the ebike. Plug the charger back into the battery pack.

  • Error 603 Internal battery pack error, sometime while charging. Unplug the charger, stop and restart the ebike.

  • Error 605 Battery pack temperature error, sometimes while charging. The battery is outside of the permissible temperature range. Unplug the charger and switch off the ebike to allow the drive unit to either cool down or heat up to the permissible temperature. Restart the ebike.

  • Error 606 Battery pack temperature error. Check the wiring. Restart the ebike.

  • Error 610 Battery pack temperature error while charging. Restart the ebike.

  • Error 620 Battery pack voltage error. Replace the charger.

  • Error 640 Charging error. Restart the ebike.

  • Error 655 Internal battery pack error. Switch off the ebikes. Remove the battery pack and reinsert it. Restart the ebike.
LED FLASH CODES - Bosch battery
  • 3 LEDs flashing. Battery pack too warm or cold. Disconnect the battery from the charger until the charging temperature range has been reached. Do not connect the battery pack to the charger until it has reached the permissible charging temperature.

  • 2 LEDs flashing. Battery pack is defective. Battery may need replacement.

  • No LEDs on when charging. Charger plug is not inserted correctly or battery contacts are dirty. Check all plug connections. Carefully clean the battery contacts using a damp cloth.

  • No LEDs on when charging. Wall socket outlet, cable or charger defective. Check household voltage, have charger checked at your bike dealer, replace the charger as needed.

  • No LED on when charging. Battery pack is defective. Have the battery checked at your bike dealer, replace the battery as needed.

  • No LEDs on when pressing the Power button. Battery pack may be fully discharged or may be defective. Try charging the battery for an hour or so. If the battery is not charging (still no LEDs on when pressing the Power button), have the battery checked at your bike dealer, replace the battery as needed.

TIP #4 - RESETTING THE BATTERY

To clear a battery related error, I would try resetting the battery. With Bosch batteries, after removing the battery from the bike, a battery reset is done by pressing and holding the battery power button for 10 seconds and then reinstalling the battery in the bike.

If the power button is not immediately visible or accessible, you may need to use a tool e.g. screwdriver, small punch or thin rod, to reach and gently press the power button through the hole or opening in the battery cover.

TIP #5 - CONSULT YOUR EBIKE OWNER'S MANUAL

Read what your ebike/battery manufacturer says about battery care, maintenance and problem troubleshooting. Take a look at this post for manufacturers guides and other resources available to e-bike owners.

TIP #6 - ASK A PROFESSIONAL

Always reach out to your nearest bike shop/dealer or battery manufacturer for professional expertise and assistance with using your battery, troubleshooting or resolving battery-related issues. Don't rely on contents posted on social media and public forums for professional advice. In other words, take everything you read or watch on social media with a grain of salt!

WHAT'S ALSO NEW IN THIS THREAD?
 
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Battery health issues and troubleshooting battery degradations seem to be a recurring topic. I've posted a few tips in this thread that may be of interest to anyone having battery issues. Let me know your feedback!

 

leehop71

Member
Sep 2, 2023
21
12
Florida
What is your experience and recommendations for taking care of your lithium-ion batteries and maximize their lifespan and performance?

What do you do to keep your ebike battery in top shape?

Over the years, I wrote down a few best practices and made the list below. I'm interested in your thoughts and feedback.
  • Length of time at full or zero charge is what degrades batteries. Never discharge the battery below 10%.
  • Never keep the battery charged at 100% unless you're about to ride. For example, fully charge the battery only the night or morning before a ride.
  • Charge the battery at room temperature (15-20° C). Charging at low temperatures, below 0°C will irreparably degrade the cells. Heat above 35°C when discharging or riding will degrade the battery.
  • Store the battery at room temperature (15-20° C). When storing a battery for extended time, keep it at 50-60% charged. In storage, verify the charge every 6 months and recharge as needed.
  • Batteries should not be recharged immediately if they are only slightly discharged. Recharge the battery only if between 10% and 20%
  • Always let the battery cool down for at least 30 min after recharging it before going for a ride.
  • Let the battery cool down for at least 30 min after the ride before recharging it.
  • On first use, drain the new battery (10-20%) and fully charge it (100%) at least 5 times initially.
[Edited] Below list updated per forum members feedback and suggestion:
  • Avoid charging to 100% unless a full charge is needed for the next ride [thanks to @Mikerb]

Find some best practices for battery care and maintenance, as well as a few battery troubleshooting tips in these newer posts:
The ONLY ‘on the fence’ battery routine I have is where to store the battery BETWEEN rides!

Some ‘experts’ say don’t store battery in the cold or heat, but then some say nothing is lost by keeping battery in the bike between rides, as long as you don’t CHARGE it in the heat!?!?

So, here in SW Florida, during the summer, do a bring it in between rides, or just leave it IN the bike, but charge inside?!?
 

@leehop71, between rides (short-term storage scenario), battery packs should ideally be kept in a dry location at temperatures between 5°C (41°F) and 20°C (68°F) to maximize their lifespan.

So your battery could stay inside the bike between rides if the bike can be stored at these temperatures. Otherwise, it may be preferable to bring the battery inside at room temperature 15-20° C (60-70°F).

For charging, you're correct, batteries shouldn't be charged in the heat, and never at temperatures above 35-40°C (100°F). Ideally, batteries should be charged at room temperature. They should also be kept out of direct sunlight.

What temperatures and humidity are you getting for this time of year?
 
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leehop71

Member
Sep 2, 2023
21
12
Florida
@leehop71, between rides (short-term storage scenario), battery packs should ideally be kept in a dry location at temperatures between 5°C (41°F) and 20°C (68°F) to maximize their lifespan.

So your battery could stay in the bike between rides if the bike can be stored at these temperatures. Otherwise, it may be preferable to bring the battery inside at room temperature.

What temperatures and humidity are you getting for this time of year?

For charging, you're correct, batteries shouldn't be charged in the heat, never at temperatures above 35-40°C (100°F). They should also be kept out of direct sunlight.
Brutal heat/humidity here in SW Florida from June through October! My routine year round will be to bring battery in between rides.

My battery is designed to shut off when the key is turned and it pops loose from the bike!

Thanks Rider
 

TimC7

Ovine Assaulter
Apr 22, 2023
274
1,058
UK
TBH I don’t see how anyone could know what level the charge is at when charging a bike battery.🤔
Trial and error - easy to check % with STunlocker and then see how much extra after an hour charge. I always boost mine to ~60% for storage and usually get it close enough.
 

RipGroove

Active member
Jun 3, 2022
375
188
Glos/UK
TBH I don’t see how anyone could know what level the charge is at when charging a bike battery.🤔
Mine shows the percentage of charge while charging. If yours does not then as others have said just check the percentage before and after a certain amount of charge to see how much it's gone up in that given time and use that for calculating how long to charge it for when starting at any given percentage.
20230903_150750.jpg
 

RipGroove

Active member
Jun 3, 2022
375
188
Glos/UK
Does your bike not have any LEDs or anything that show the percentage of charge while charging? The last few bikes I've had have all had some way of seeing the rough charge percentage by way of LEDs or some kind of bar meter where each block represents a certain amount of charge.
 

leehop71

Member
Sep 2, 2023
21
12
Florida
Does your bike not have any LEDs or anything that show the percentage of charger while charging?
It has 3 lights on the battery, red, yellow, and green.

From the research I’ve seen, half of them say charging to 100% is fine, just don’t store it at 100%, some advise the 80% rule.

Basically, from what I understand, the 80% rule only brings minimal life to the battery.🤔
 

TimC7

Ovine Assaulter
Apr 22, 2023
274
1,058
UK
I am an anal person that keeps charger AND battery inside, between rides, and charge inside using a laptop cooler, but not anal enough to be concerned about the 80% rule.🤷🏼
I'm more concerned about what happens when a battery at 100% suddenly lets go . .
 

Suns_PSD

Active member
Jul 12, 2022
522
439
Austin
I've followed all of the rules in this thread and have 9 or 10 partial charges on my battery and exactly 3 full charges.
This morning I did the 3rd full charge in my home (my Relay battery is removable and my garage is pretty hot) and within 5-10 minutes of the chargers full charge indicator light going green it was unplugged.
About an hour later I installed the battery and used the App to check percent of charge and it was at 98% with no pedaling done but it had read 100% charge when I previously gave it a full charge 2x.
So it would appear that at only around 120 miles of use I had lost 2% capacity.
It's not a huge deal but I'm a bit surprised by the quick degradation in spite of me doing all the things (keep battery room temp except when riding, charge to 60% after use, allow to cool before charging, never been below 20%, depart usually at 80% charge except the 2 times at 100% & now one at 98%).
Anything I should be doing differently or is this just par for the course?
If I left it fully charged longer or more often would the battery cells rebalance? Starting to think I'd be better off just charging it to 100% every ride.
 

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