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

[Mikerb]

There are specific storage and charging temperature limits (1)...............and there are recommendations regarding temperature and humidity to ensure maximum longevity of the battery (2). If you have to store the bike/battery in a shed or garage all year round ( in the UK) you merely risk it not performing to maximum capacity for as long as one stored indoors (2). The difference is probably not that great!!

PS if you are concerned a bout bike security when stored in a shed or garage because it has a non removeable battery, remove the wheels and keep them indoors...........on most bikes it is a 2 minute job and a bike with no wheels is going to be less attractive.
I store my bikes in the house but if I am working on a bike and it has to stay in the garage on a workstand for a few days, I remove the battery and both wheels and keep them indoors. Worse case scenario, the bike gets nicked but at least I have a battery and 2 wheels

 

[TimC7]

There are specific storage and charging temperature limits (1)...............and there are recommendations regarding temperature and humidity to ensure maximum longevity of the battery (2). If you have to store the bike/battery in a shed or garage all year round ( in the UK) you merely risk it not performing to maximum capacity for as long as one stored indoors (2). The difference is probably not that great!!

Shimano (and others) say if you operate below the minimum temps you won't damage the battery, and performance/capacity will return to normal when temps go back up so no worries with garage storage (in the UK).

 

[Planemo]

Yeah most li-ions are specced down to a -20 degC operating/storage temp so normally well within UK temps. All that happens when discharging them at these temps is a range loss which can be a lot more than many think.
Of note though is that charging temp should ideally be above 0~10deg C depending on what specific cell is used (eg Sanyo GA18650 being 10deg, Samsung 21700 being 0 deg)....which could impact UK temps. My battery is always stored in the house so not a problem but it wouldn't be ideal to charge an empty pack immediately after it's been sitting in a shed at -10 overnight.

 

[Binhill1]

Shimano (and others) say if you operate below the minimum temps you won't damage the battery, and performance/capacity will return to normal when temps go back up so no worries with garage storage (in the UK).

I suppose mine occasionally gets left now and then probably not when it's baltic though and its a faff running a cable from house to shed for charging . I should have put power in there years ago it probably won't happen now. I was after a gravel bike with maybe a 500 battery thats removable as I am intending touring. Unless I'm willing to pay a fortune its not going to happen. Can't wheel a bike in to a cafe but they probably let you charge a battery. Worse scenario you pay something.

 

[Ali_Foto]

One question ; in TQ e-bike system , the e-bike use the range extender battery power first unit it comes to 0 % then switch to main battery so, which one is better to do,
1)connect the range extender when the main battery is discharged to less than 10%
2)The range extender battery to be connected to the e-bike permanently and charge it with main one together.

 

[TimC7]

One question ; in TQ e-bike system , the e-bike use the range extender battery power first unit it comes to 0 % then switch to main battery so, which one is better to do,
1)connect the range extender when the main battery is discharged to less than 10%
2)The range extender battery to be connected to the e-bike permanently and charge it with main one together.

Maybe read the manual?

 

[Ali_Foto]

Maybe read the manual?

In the manual, it has mentioned that charge the range extender immediately when it reached to below 5% , since range extender discharged first then TQ drive switch to main battery, so it is strange.

 

[Funkeydunk]

Bosch battery guide.

https://www.bosch-ebike.com/fileadmin/EBC/Service/Downloads/Akku_Guide/Akku_Guide_MY24/Bosch-eBike-Akkuguide-EN-GB.pdf

 

[Anantmundhra]

Do's:

• Charge the battery after every ride.
• Store the battery in a cool, dry place.
• Keep the charge level between 20-80% for optimal health.
• Use the charger provided by the manufacturer.
• Clean the battery and connections regularly.

Don'ts:

• Avoid overcharging or draining to 0%.
• Don’t expose the battery to extreme heat or cold.
• Don’t submerge the battery in water or use high-pressure washing.
• Don’t disassemble or tamper with the battery.

 

[randycpu]

Do's:

• Charge the battery after every ride.
• Store the battery in a cool, dry place.
• Keep the charge level between 20-80% for optimal health.
• Use the charger provided by the manufacturer.
• Clean the battery and connections regularly.

Don'ts:

• Avoid overcharging or draining to 0%.
• Don’t expose the battery to extreme heat or cold.
• Don’t submerge the battery in water or use high-pressure washing.
• Don’t disassemble or tamper with the battery.

Mostly correct except for 2 related data points:
1 - Battery life is compromised the longer the State of Charge (SOC) remains close to 100%.
2 - Battery life is extended when batteries are stored at 50% SOC.

Therefore, "charging after every ride" is detrimental to battery longevity. The best process is to store the battery at 50% SOC and charge to 100%just before riding.
Of course this requires planning and may not be convenient. You can make compromises between better battery life and convenience armed with this knowledge

 

[Wilko58]

I've got a 4 year old Whyte with a Bosch 625 battery.
I jet wash it, although carefully.
The battery has been out of the frame around 4 times.
It is almost always charged to 100%.
And is often left for weeks, and even months.

As far as I can tell, there hasn't been any degradation.

 

[Binhill1]

I've got a 4 year old Whyte with a Bosch 625 battery.
I jet wash it, although carefully.
The battery has been out of the frame around 4 times.
It is almost always charged to 100%.
And is often left for weeks, and even months.

As far as I can tell, there hasn't been any degradation.

Same here 5 years 10,000 miles still showing 100 and getting samerange as when new. . I don't believe too much I read on here , in fact some engineer on here is reinventing the whee I hear.

 

[TimC7]

I thought the advice wrt not charging to 100% for storage was more about limiting the possibility of it going bang . .

 

[Wilko58]

I thought the advice wrt not charging to 100% for storage was more about limiting the possibility of it going bang . .

I haven't heard that as a reason for not charging to 100%
The exploding batteries are those that are NOT genuine eMTB batteries, which are tested and certified.
The only one I know of that stuff exploded/caught fire was because the owner put the wrong screw in the frame and went through the battery casing.

 

[Binhill1]

I thought the advice wrt not charging to 100% for storage was more about limiting the possibility of it going bang . .

I was involved in recovering a beacon with a battery in it from the sea bed that had been down there for 10 years . You would not believe the amount of hours spent at meetings and all the precautions we had to take to get it on board and back onshore. So obviously all batteries are high risk . Leaving anything charging unattended is always a nono in all safety instructions nowadays.

 

[michael.kozera]

I haven't heard that as a reason for not charging to 100%
The exploding batteries are those that are NOT genuine eMTB batteries, which are tested and certified.
The only one I know of that stuff exploded/caught fire was because the owner put the wrong screw in the frame and went through the battery casing.

Correct.

And if I could add.

Charging to 100% which I do all the time for decades now has resulted in little to no noticeable degradation.

I will say leaving it charged at 100% is detrimental, but we talking like 100% charged for like weeks, even months at a time. However, it's important to note, 100% charge is not a fire risk, it's a degradation risk.

 

[dirtdinner]

Personally I charge the battery (and range extender if using) to about 70 to 80% before storage.

I charge it to full 100% whilst getting ready on the morning of a ride (or the night before).

 

[michael.kozera]

Personally I charge the battery (and range extender if using) to about 70 to 80% before storage.

I charge it to full 100% whilst getting ready on the morning of a ride (or the night before).

Exactly.

I do the same. 60-80% for long term storage. About 3.7-3.9v per cell.

Fully charged. Sometimes even over charged before I hit the trail. Like 4.25-4.35v per cell

 

[randycpu]

Exactly.

I do the same. 60-80% for long term storage. About 3.7-3.9v per cell.

Fully charged. Sometimes even over charged before I hit the trail. Like 4.25-4.35v per cell

Charging over 4.20 volts/cell is very dangerous for NMC lithium chemistry (all bike batteries). This behavior will cause overheating and leads to thermal runaway (fires). Any decent BMS will not allow this kind of overcharging.

 

[michael.kozera]

Charging over 4.20 volts/cell is very dangerous for NMC lithium chemistry (all bike batteries). This behavior will cause overheating and leads to thermal runaway (fires). Any decent BMS will not allow this kind of overcharging.

Most expensive bms can be programed.

I've been doing this for decades. Not a single issue so far.

Also. No 4.35v is perfectly safe. Read the spec sheet of any decent cell.

4.4v is bad yes.

 

[RJUK]

It's well known that the most degradation occurs at 100% SOC, so it's better to store it at a lower SOC and charge just before riding.

Whether you notice it or not, if you've always stored your battery at 100% over thousands of miles then you will have degraded it more than if you hadn't. That said, batteries will degrade even if you don't use them and even if you store them at a lower SOC. They just degrade slower at a lower SOC than a higher SOC. The bike may show 100% still, but it will have degraded and lost capacity.

What you do with that information is up to you. If you don't care about losing more capacity per year than you would have if you'd kept the battery at a lower SOC, then carry on storing the battery at 100%, but if you're in this thread because you're interested in extending the working life of your battery and limiting degradation as much as possible, then storing it at a lower SOC is better. You could store it as low as 10 or 20%, the reason 40 or 50% is often suggested is so that the battery doesn't self discharge to 0%, as that kills it completely. (Indicated 0% on the bike isn't a true 0%.)

Leaving the battery stored at 40% gives a bigger buffer in case the user stores it for a longer period without charging.

There's plenty of info to back this up online.

Many people get their charging habits from old NiCad batteries that had a memory and were best charged fully and discharged fully, but that doesn't apply to lithium batteries and deep cycling the battery like this is detrimental. Shorter, more frequent charges are better, though of course you don't have much choice if you have to use your entire battery to complete a ride.

 

[mxh]

I'd store my battery at 50% if it was easier - but having to manually work out when it might reach that point, then make sure you're around to unplug it, is a bit of a pain. Wouldn't it make sense if battery chargers came with a 2 position switch - 1) Charge to 50% and 2) Charge to 100%

That way you could charge it to the 50% after a ride, then just the switch to 100% the day before you're heading out again.

Is this overly complicated to do? Why hasn't anyone offered this?

 

[dirtdinner]

At what temperature does battery damage become an issue? Over winter my shed would get down to 0 Celsius, but not much lower.

 

[randycpu]

I'd store my battery at 50% if it was easier - but having to manually work out when it might reach that point, then make sure you're around to unplug it, is a bit of a pain. Wouldn't it make sense if battery chargers came with a 2 position switch - 1) Charge to 50% and 2) Charge to 100%

That way you could charge it to the 50% after a ride, then just the switch to 100% the day before you're heading out again.

Is this overly complicated to do? Why hasn't anyone offered this?

There IS a family of charger with variable end point voltages from Luna. They also allow variable charge currents.

 

[Binhill1]

I'd store my battery at 50% if it was easier - but having to manually work out when it might reach that point, then make sure you're around to unplug it, is a bit of a pain. Wouldn't it make sense if battery chargers came with a 2 position switch - 1) Charge to 50% and 2) Charge to 100%

That way you could charge it to the 50% after a ride, then just the switch to 100% the day before you're heading out again.

Is this overly complicated to do? Why hasn't anyone offered this?

Specialized levo you can charge to 80 it has a setting in the app. Most folk use a timer.

 

[Binhill1]

At what temperature does battery damage become an issue? Over winter my shed would get down to 0 Celsius, but not much lower.

Levo manual says charge between 0c and 35c probably find a lot of disagreement on that. I take mine in house most times also if it gets stolen no battery.

 

[TimC7]

At what temperature does battery damage become an issue? Over winter my shed would get down to 0 Celsius, but not much lower.

Shimano say don't charge below 0c, don't use below -10c and don't store below -20c so it should be fine.

 

[Binhill1]

So I was out today and will be out again Wednesday. Battery is at 26 % , should I charge it up to 75 ish tonight then top it up to 100% on Wednesday before i go out . Or leave it at 26 % till Wednesday.

 

[TimC7]

So I was out today and will be out again Wednesday. Battery is at 26 % , should I charge it up to 75 ish tonight then top it up to 100% on Wednesday before i go out . Or leave it at 26 % till Wednesday.

I always charge to 60-70% because that's what Shimano say to store at, so it doesn't matter if I don't ride it for a few days, and also if I forget to charge, or the timer fails, or if I don't have time I can still go straight out for a decent ride.

 

[RJUK]

So I was out today and will be out again Wednesday. Battery is at 26 % , should I charge it up to 75 ish tonight then top it up to 100% on Wednesday before i go out . Or leave it at 26 % till Wednesday.

Sorry, only just saw this. Personally I'd leave it at 26% and then charge as late as possible before you leave. Ideally you would have the battery finish charging, then unplug it, put it in the bike and ride it straight away. (Or maybe give it a few minutes to cool if it got warm from charging.)

I tend to try to charge mine only as much as I need. For example, I often do a quick Sunday morning ride that only uses around 30% of my Bosch 750 battery, so I charge it to around 50 - 60% so that it's around 20 - 30% when I'm done.

Through summer I've been leaving the battery in the bike and even 2 weeks later without use the battery hasn't even dropped 1%. So there seems little risk that the battery will deplete to 0% unless I were to leave it in the bike for months without use.