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

[Alexbn921]

Proper care vs just plug it in and don't worry about it will increase it's lifetime 2-3x.
So many people don't care and are proud of it. It's like the shocks on your car they wear out so slow it's hard to notice the day to day degradation

A well cared for battery should last 12-15kmiles. At that point the frame/motor are pretty much done and it's time to retire it from real mountain bike duty. Most people never put this many miles on a bike.

 

[RiderOnTheStorm]

Well 15K miles doesn't seem much for a battery though!

Ranging about 50 miles per full charge cycle (for my riding/climb w/ Bosch CX 625Wh), that would mean the battery would only give me 300 cycles, kinda low end of the "useful cycle" spectrum!

I would certainly expect my e-bike and especially my motor to clock higher than 15K with normal maintenance, and if kept out of the water!

 

[Alexbn921]

Well 15K miles doesn't seem much for a battery though!

Ranging about 50 miles per full charge cycle (for my riding/climb w/ Bosch CX 625Wh), that would mean the battery would only give me 300 cycles, kinda low end of the "useful cycle" spectrum!

I would certainly expect my e-bike and especially my motor to clock higher than 15K with normal maintenance, and if kept out of the water!

I get closer to 25-30 miles per cycle and 7000ft+ climbing. Not all miles are equal. All of mine are straight up or straight down. I'm very tall and tend to wear out parts fast, even with proper care.

 

[RiderOnTheStorm]

Got it! Our mileage definitely varies!

As commercially available cells claim to have a lifespan of 500 to 600 cycles, retaining 80% of their original capacity or range, I sure hope I can get close to that level!

I was reading about some factors that affect battery life, positively and negatively. I listed them below.

While most have been discussed in this thread, one factor about "cell aging" left me wondering. Not sure how big of a role is the cell aging process (chemical level) playing on battery life and performance.

Question: When purchasing a new battery, do you check the manufacturing date, and avoid buying an older battery or one that's been sitting on the shelves for too long? For Bosch batteries, here is the manufacturing date table.

Curious about what's the typical shelf life of lithium-ion batteries that we use in our ebikes.

POSITIVE FACTORS ON BATTERY LIFE

• Slow charging (using 2 Amp charger rather than 6A charger).
• Slow discharging (prefer ECO/TOUR modes to TURBO).
• No deep discharge.
• Charging only to 80% for most rides.
• Charging only to 50% for storage.
• Charging and storing the battery at room temperature.

NEGATIVE FACTORS ON BATTERY LIFE

• Deep discharge (leaving battery to drain to a fully discharged state for some time without recharging).
• Leaving battery charged at 100% when in storage
• Temperatures too high or too low when charging or storing.
• Cell aging. Older battery
• Faulty BMS/cells

 

[folmonty]

My laptop has software which limits charging to 60% if desired but when it comes to all the other devices not sure if the "juice is worth the squeeze?" One thing that does seem to kill batteries is leaving them completely discharged for a length of time.

 

[RiderOnTheStorm]

My laptop has software which limits charging to 60% if desired but when it comes to all the other devices not sure if the "juice is worth the squeeze?" One thing that does seem to kill batteries is leaving them completely discharged for a length of time.

I see your point. Windows/Mac/Linux/Android distributions these days have some advanced battery management apps and capabilities compared to ebikes.

I don't have the same level of control or visibility at the software app level on my Bosch-powered ebikes (mainly due to the proprietary Bosch diagnostic software only available to dealers ). Other motor brands may be more open (Bafang?).

On ebikes though, from a battery replacement cost perspective, some reasonable battery care could be worth it:
-replacing laptop battery: $50-$100
-replacing ebike battery: $600-$1,200

Quite a different "investment"!

 

[RiderOnTheStorm]

I've read more recent articles on proper ebike battery maintenance. Link below.

Helpful guide in my opinion and very much aligned with the guidance and best practices being discussed in this thread

Complete E-Bike Battery Care Guide

Discover the do's and don'ts of e-bike battery care, ensuring prolonged efficiency, optimal performance, and extended longevity.

ebikes.org

 

[RipGroove]

How to safely charge the battery to 100% without risk of overcharging/overheating
+
How to charge the battery to a required percentage (ie: 60% for storage purposes)​

Apologies if this has already been covered in this thread and/or is already common knowledge. I'm using this method along with my charger plugged into a simple plug countdown timer to help minimize the risk of overcharging the battery (due to a charger fault or whatever) when charging to 100% and risking overheating/fire and also for hitting the storage charge recommendation of 60%. The recommended storage charge for a lot of batteries is around 60% so if you want to achieve that without some kind of an intelligent charger then you can use the example below:

Battery Capacity = 750wh
Required Charge Percentage = 10% (If your battery is at 50% and you wanted to increase it to 60%)
Charger Output = 144W (My charger is 36V 4A, so 36V x 4A = 144W)

Time to Charge (Hours) = (750wh x 0.1) / 144W (So that 0.1 is the 10% charge that I required, so if you want 20% charge then change that to 0.2)
Time to Charge (Hours) = (75wh / 144W)
Time to Charge (Hours) = 0.5208

Time (Mins) = 0.5208 x 60
Time (Mins) = 31.25

My example above is for a Bosch 750wh battery and standard Bosch charger which outputs 36V and 4A with the battery being at 50% charge and me wanting to increase it to 60%. I have tested this and it has worked fine for me so far, now I know my charger takes roughly 30mins to charge 10% I just set my plug timer and switch it on. Adjust the figures to suit your battery, charger and required percentage increase and it should all work out. If of course you happen to have the same battery and charger as me then you can save yourself the time by knowing that around 30mins charging = around 10% charge.

***Obviously it isn't recommended to leave your battery charging while unattended while you are not home***

 

[Stephen B]

Are these chargers good?

EBC Universal Smart Charger - 36v 2 amp Lithium Ion Battery

36V 2A Smart Charger / Selectable charge voltage to prolong battery life - selectable 80%, 90%, 100% charge voltage /90~264VAC - Electrify Bike

www.electrifybike.com

You can set it to 80%, 90% or 100%

 

[randycpu]

Are these chargers good?

EBC Universal Smart Charger - 36v 2 amp Lithium Ion Battery

36V 2A Smart Charger / Selectable charge voltage to prolong battery life - selectable 80%, 90%, 100% charge voltage /90~264VAC - Electrify Bike

www.electrifybike.com

You can set it to 80%, 90% or 100%

YES, if you want to preserve cycle life (overall number of charge cycles). I own one of these from Luna Cycles. This is much more controlled than using a timer arrangement.
However, these will create cell imbalance if used exclusively at any setting other than 100%, as the BMS only balances at top of charge. So every 1 out of 3 charges should be to 100%.
Alternatively, use the 80% setting when storing the bike / battery for more than a day.

 

[RiderOnTheStorm]

Thanks for sharing!✌ Smart chargers seem like a great option. I haven't tried them yet, so cannot comment at this time.

I've been using the charging table that Bosch published in their Battery Guide (below). Helped me quickly estimate how long I need to charge my bosch batteries for a given charging goal.

So with my Powertube 625Wh and a standard 4A charger, it would take 4.9 hr to charge my battery to 100% and 2.1 hr to charge it to 50% from full discharge.

I found that I get about 20% charge per hour. This seems consistent with @RipGroove's precise calculations.Of course YMMV.

 

[RipGroove]

This is much more controlled than using a timer arrangement.

The £14 timer I have is extremely easy to use and means you are still using the original charger (keeping whatever methodology it uses to charge the battery). And I have perfect control over exactly how much charge I want to add and it shuts off automatically.

This is literally all I have to do:

Walk up to bike
Press CTD (Countdown)
Press the Hour and Minute buttons to dial in how much charge I want it to charge (30mins = 10% charge for me)
Press Enter
Walk away

It's literally like using a microwave, it even beeps when it's finished if you want it to and I can dial in exactly how much charge I want technically down to less than a single percent.

The one single downside is not being able to change the amerage rate that it charges at as that is fixed by the Bosch charger, but that's it, even if I could change the amps down to 2 I probably wouldn't bother anyway because you'd be looking at an hour's charging for just 10% charge on my particular battery and I'm sure if used correctly (ie maintaining good charging practices) the Bosch chargers 4.0a is perfectly fine and safe and maintains a decent battery life.

With a bit of thought and a cheap timer I can't see how a third party charger would be any better. I'm not expert though so


15mins dialled in for adding 5% charge

And after its shut itself off after 15mins the bike has exactly 5% more charge than it did have (from 60% to 65%)

I can't see me needing any more control than that tbh.

 

[RiderOnTheStorm]

@RipGroove, great feedback on your charging method! Thanks for the details!

So, once you figure out your battery charging rate (% per hour), the use of an electronic timer makes a lot of sense!

Do you happen to have a link to the programmable timer outlet that you're using?

 

[RipGroove]

@RipGroove, great feedback on your charging method! Thanks for the details!

So, once you figure out your battery charging rate (% per hour), the use of an electronic timer makes a lot of sense!

Do you happen to have a link to the programmable timer outlet that you're using?

https://amzn.eu/d/dQgQdwg

That's the one I have, it works perfectly and seems to be well made but any simple timer that has a countdown mode will work.

It was £13 something or other when I bought it a while back.

 

[RiderOnTheStorm]

Back to some earlier posts expressing scepticism about the benefits of battery care, here is an article from University of Michigan's Center for Sustainable Systems where researchers developed a list of 9 best practices for battery lifetime extension. See diagram below.

This article emphasizes that the main variables impacting battery health are: temperature, state of charge, and current, and it gives general guidelines from U-M researchers to maximize lithium-ion battery lifetime.

It concludes by saying: "This work by such a respected research institution as the University of Michigan is an important first step toward creating a generational change in how consumers use and treat batteries.”

A good read in my opinion!

Article source: tips for extending the lifetime of lithium-ion batteries

 

[RiderOnTheStorm]

On the battery health fade topic, I've seen lithium batteries lose up to 5-10% of their capacity over 3 years, and up to 10-20% capacity over 6 years when given proper care.

I was wondering what can be considered "normal" capacity degradation expected over time vs. abnormal capacity loss which may fall under manufacturer warranty?

I started compiling battery manufacturers warranty info to get a sense of what capacity loss would be considered abnormal from the manufacturer point of view and require futher action (repair, replacement). See table below.

It appears most battery manufacturers warranty their battery to hold a minimum of 60% of full charge capacity (for 500-1000 charging cycles) by the end of a 2-3 year warranty period.

So this is telling me that any capacity degradation over 40% during the battery warranty period could be considered abnormal. Conversely, any degration under 40% would remain in the "normal" range.

Battery Manufacturer	Warranty Period	Charge Cycles Guaranteed	Remaining Capacity Guaranteed
Shimano	2+ years	1,000	60%
Yamaha / Giant	3 years	700	50%
Bosch	2 years	500	60%
Brose / Specialized	2 years	300	75%
Bafang	2 years	Not specified	60%

 

[jimbob]

You do of course have to prove the degradation to them to be actually able to claim the wattanty...

I'd say 60% at 1000 cycles is probably about right though based on phone batteries.

 

[Dazzling1984]

following!!! =)

 

[RiderOnTheStorm]

@jimbob, you could periodically check your battery health (or ask your LBS to run a diag) for degradation,

Or like @Binhill1 mentioned in another thread, ride a trail or route that you know well (with same power settings) and compare remaining charge with prior rides to detect any significant capacity degradation.

If it feels the battery is fading abnormally, it may be time to visit your LBS for a full health check and discuss next steps like replacement under or outside warranty.

 

[jimbob]

Unfortunately the problem is proving it to get the warranty honored. Its a well known issue for some of the shimano batteries but they just ignore the claims. I tried to get a battery warranted but the software the LBS has had the capability removed by shimano to even read it out. They then changed the firmware (shimano, via a firmware update to everyone) to give a false reading. They've also updated their warranty terms to make it harder.

Easy to measure yourself, far harder to actually prove sufficiently to get a replacement! And that's not taking into account the lack of understanding from most LBSs of batteries.

When I've got a moment I'll post up a couple of graphs I've got of battery capacity vs cycles from actual measured data.

 

[RiderOnTheStorm]

@jimbob seems you had a terrible experience with your Shimano battery!

I see your point about the difficulties to prove a product is defective if the manufacturer doesn't play fair and changes the rule of the game!

Were you able to escalate this to the bike manufacturer? Or have another LBS look into the issue?

 

[MasterDabber]

I'm considering buying my first emtb and have found this a really interesting and useful thread. Lots of detailed info. Needless to say I have a couple of very dumb questions.
After a ride I'm down to say 40%... I'm going to ride the following day..... do I recharge to 100% so I can set off with a full battery or do I only recharge to say 80%, then top up the charge again in time for when I start my next ride the following day.
As I tend to ride every other day the same question applies. Hope that makes sense.

 

[RipGroove]

If I knew i

I'm considering buying my first emtb and have found this a really interesting and useful thread. Lots of detailed info. Needless to say I have a couple of very dumb questions.
After a ride I'm down to say 40%... I'm going to ride the following day..... do I recharge to 100% so I can set off with a full battery or do I only recharge to say 80%, then top up the charge again in time for when I start my next ride the following day.
As I tend to ride every other day the same question applies. Hope that makes sense.

If I knew I was riding early the next day I'd just leave it a couple of hours after day ones ride (to let the battery cool down fully) then charge it to 100% ready for the next morning.

If day twos riding is later on in the day I'd personally leave it a couple of hours after day ones ride then charge it up to 60% then on the morning of day two I'd top the charge up to 100%.

For the sake of one night I wouldn't worry too much about it.

 

[MasterDabber]

If I knew i

If I knew I was riding early the next day I'd just leave it a couple of hours after day ones ride (to let the battery cool down fully) then charge it to 100% ready for the next morning.

If day twos riding is later on in the day I'd personally leave it a couple of hours after day ones ride then charge it up to 60% then on the morning of day two I'd top the charge up to 100%.

For the sake of one night I wouldn't worry too much about it.

That makes a lot of sense. Thanks, I'm just trying to get my head around all things "emtb" and probably overthinking it.

 

[RipGroove]

That makes a lot of sense. Thanks, I'm just trying to get my head around all things "emtb" and probably overthinking it.

As you can see from this thread I think most people are trying to figure out what's actually best for batteries and inevitably there will be all sorts of different opinions floating about. General rules for me are:

Give it at least few hours to cool down after a ride before charging it again, then top up to 60%

Leave it at 60% whenever I can

Top up to 100% charge on the morning of a ride and if that's not possible (it takes circa 2hrs for mine to go from 60-100%) then I'll do it on the evening beforehand

I keep the battery in the bike in my garage during the Spring, Summer and Autumn and through the Winter I bring the battery inside the house and keep it at 60% charge.

 

[Binhill1]

As most top up a few hours after a ride to 80 after then top up to full if I think I will do a long ride on the night before or on the day . I usually take battery in to house so if bike gets nicked they have no battery.

 

[Alexbn921]

Get a wifi controlled plug. Then you can set timers, programs for early morning charging and even start charging from work so it's ready when you get home.

As others have said.
Let it cool after a ride
Keep it at 60%
Charge to 100% just before you ride. This balances the batteries and as long as its used right away does no damage.
Try not to go below 15%.

 

[RipGroove]

This thread got me thinking, if you'd charged your battery up to 100% anticipating a ride which ended up get cancelled and for whatever reason you didn't have time or couldn't ride the bike to drain it down to a storage charge like the weather was really bad or you were going on holiday or something we don't currently have any way to discharge it without riding.

Battery manufacturers should start making attachments for their ebike batteries like emergency/workshop lights or whatever that you can slot your battery into. Be handy in a power outage or for camping or whatever also. Bosch especially should have the network to achieve that because they make all sorts of lights and power tools and all that. The possibilities of ebike battery powered gadgets is endless.

 

[Binhill1]

This thread got me thinking, if you'd charged your battery up to 100% anticipating a ride which ended up get cancelled and for whatever reason you didn't have time or couldn't ride the bike to drain it down to a storage charge like the weather was really bad or you were going on holiday or something we don't currently have any way to discharge it without riding.

Battery manufacturers should start making attachments for their ebike batteries like emergency/workshop lights or whatever that you can slot your battery into. Be handy in a power outage or for camping or whatever also. Bosch especially should have the network to achieve that because they make all sorts of lights and power tools and all that. The possibilities of ebike battery powered gadgets is endless.

I worried about that when I first got bike. I went away for a month at a time and a few times it was left fully charged . Same with running it till its nearly flat I do that as well. Doesn't seem to have done any harm im still getting same range .

 

[RipGroove]

I worried about that when I first got bike. I went away for a month at a time and a few times it was left fully charged . Same with running it till its nearly flat I do that as well. Doesn't seem to have done any harm im still getting same range .

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.