Battery condition on NEW e-bikes that sat in warehouse for years

[erider1]

There are many NEW e-bikes on sale today that are 2, 3 or even 4 years old.
The battery that is made of say 18650 cell (most often) has been sitting in that bike since new ??

Does anyone know how things work and what to expect as for the condition of battery, when buying say 3 year old NEW model from dealer.

If the bike was boxed long time ago and sat somewhere in warehouse for 2 years, and if no-one was charging the batteries;
Li-Ion batteries should be stored at 40-60% of charge and voltage should not drop below 2.5V.

Are people getting degraded batteries when they buying several years old e-bikes?

 

[Joecrow]

Are people getting degraded batteries when they buying several years old e-bikes?

Given the very big discounts offered on many Gen 4 2023/4 Bosch powered bikes I would say it was well worth any risk. In the worst case I believe such bikes would still be subject to standard warranty from the purchase date.

 

[Tooks]

Depends on the bike, and the battery really.

When brand new cells are manufactured, the building process creates a passivation layer that protects the battery from excess self discharge and is only overcome when the battery starts being used properly, ie charged and discharged.

Passivation gives batteries a ‘shelf life’, often measured in years. Without it, all cells would need to be made ‘just in time’ and there wouldn’t be shelf stock to manufacture battery packs.

It’s not something I’d worry about in any ‘branded’ bike with a known battery pack.

 

[jackamo]

There are many NEW e-bikes on sale today that are 2, 3 or even 4 years old.
The battery that is made of say 18650 cell (most often) has been sitting in that bike since new ??

Does anyone know how things work and what to expect as for the condition of battery, when buying say 3 year old NEW model from dealer.

If the bike was boxed long time ago and sat somewhere in warehouse for 2 years, and if no-one was charging the batteries;
Li-Ion batteries should be stored at 40-60% of charge and voltage should not drop below 2.5V.

Are people getting degraded batteries when they buying several years old e-bikes?

The fact they haven't been used or even fully charged and stored in a warm dry condition they should be like new .

 

[erider1]

Good info, thanks guys. Never heard of passivation before.
Also first hits on Internet returning passivation for metals, but then there is more about passivation in batteries.
Good info, for example, on spectrumbatteries.com website...

 

[erider1]

About the battery warranty. For example Specialized says, it must last for 2 years or 300 cycles.
BUT it does not specify how the durability is measured???

After 2 years or 300 cycles what is level / capacity/ % or original state should there be? and more importantly how do you, as a consumer measure that for eventual warranty? Anyone knows the protocol?

Global Warranty

From seasoned pros and weekend warriors to kids and commuters, if you ride, we’re here for you. We believe that bikes have the power to change lives, and this simple truth drives us to be and do better.

www.specialized.com

 

[E-MAD MALC]

About the battery warranty. For example Specialized says, it must last for 2 years or 300 cycles.
BUT it does not specify how the durability is measured???

After 2 years or 300 cycles what is level / capacity/ % or original state should there be? and more importantly how do you, as a consumer measure that for eventual warranty? Anyone knows the protocol?

Global Warranty

From seasoned pros and weekend warriors to kids and commuters, if you ride, we’re here for you. We believe that bikes have the power to change lives, and this simple truth drives us to be and do better.

www.specialized.com

Just an overview of Bosch battery

Bosch CX Performance battery can typically handle around 500 to 1,000 full charge cycles before its capacity starts to degrade significantly.

Here's a more detailed breakdown:

• Average Lifespan:
  Bosch e-bike batteries are known for their durability, and a well-maintained battery can last for several years, potentially 7-10 years or more.
  
  
• Charge Cycles:
  While the number of charge cycles varies, a common estimate is around 500 to 1,000 full charges.
  
  
• Factors Affecting Lifespan:
  Several factors can influence the lifespan of your battery, including:
  
  • Charging Habits: Charging to 100% for every ride may reduce the number of charge cycles compared to charging more strategically.
    
    
  • Storage Conditions: Storing the battery in a cool, dry place can help prolong its life.
    
    
  • Use Intensity: Frequent, heavy use can lead to faster degradation.
    
• Signs of Battery Aging:
  As a battery ages, you might notice:
  
  • Reduced Range: The battery might not hold a full charge for as long as it used to.
    
    
  • Prolonged Charging Time: It may take longer to fully charge the battery.
    
    
  • Loss of Power: You might experience reduced performance, especially during climbs or when using higher assist levels.
    
• When to Replace:
  If you notice significant signs of battery aging, it may be time to consider replacing your battery.

 

[E-MAD MALC]

Just an overview of Bosch battery

Bosch CX Performance battery can typically handle around 500 to 1,000 full charge cycles before its capacity starts to degrade significantly.

Here's a more detailed breakdown:

• Average Lifespan:
  Bosch e-bike batteries are known for their durability, and a well-maintained battery can last for several years, potentially 7-10 years or more.
  
  
• Charge Cycles:
  While the number of charge cycles varies, a common estimate is around 500 to 1,000 full charges.
  
  
• Factors Affecting Lifespan:
  Several factors can influence the lifespan of your battery, including:
  • Charging Habits: Charging to 100% for every ride may reduce the number of charge cycles compared to charging more strategically.
    
    
  • Storage Conditions: Storing the battery in a cool, dry place can help prolong its life.
    
    
  • Use Intensity: Frequent, heavy use can lead to faster degradation.
• Signs of Battery Aging:
  As a battery ages, you might notice:
  • Reduced Range: The battery might not hold a full charge for as long as it used to.
    
    
  • Prolonged Charging Time: It may take longer to fully charge the battery.
    
    
  • Loss of Power: You might experience reduced performance, especially during climbs or when using higher assist levels.
• When to Replace:
  If you notice significant signs of battery aging, it may be time to consider replacing your battery.

Also if purchasing as a new bike from a dealer the warranty must start from that date of purchase

 

[erider1]

Also if purchasing as a new bike from a dealer the warranty must start from that date of purchase

You information about Bosh battery is misleading and incomplete.
Also I have not asked about the battery care but about special case of buying a NEW bike when with battery in that bike was made long age.
Not sure if you trying to promote certain manufacturers here, but below is copied from Bosh warranty section:

basically it says: If you buy a NEW bike with Bosh battery system and the battery in the bike is new but was manufactured more than 4 years ago, you will have NO WARRANTY on the battery... You are on your own!!

 

[Dino24]

Generally speaking, batteries degrade over time. I wouldn't buy a bike with more than a years old battery.

 

[Tooks]

Generally speaking, batteries degrade over time. I wouldn't buy a bike with more than a years old battery.

If Bosch are happy to warranty a 3yr 11monty old battery, then I think people should be comfortable buying it too.

See earlier post ref passivation, it gives unused batteries a long shelf life, up to 4 years seems entirely plausible.

A 4 year old e-bike still languishing for sale in a shop is probably a rare occurrence and in any event should be priced more than reasonably to factor in a new battery.

 

[Dino24]

If Bosch are happy to warranty a 3yr 11monty old battery, then I think people should be comfortable buying it too.

See earlier post ref passivation, it gives unused batteries a long shelf life, up to 4 years seems entirely plausible.

A 4 year old e-bike still languishing for sale in a shop is probably a rare occurrence and in any event should be priced more than reasonably to factor in a new battery.

Sure but still I wouldn't buy it as if the battery explodes in the garage, I doubt bosch will cover the damage. For me is a no go.

 

[Stihldog]

I haven’t seen or heard of a Bosch battery failure in my circle. (12+ bikes).My Bosch 625wh battery is 5 years old. The QC on these batteries seems to be fairly good. I charge almost daily …and the lowest full charge I’ve seen has been 98%, but mostly 100%.

IMO the biggest culprit for battery failures is extreme changes in ambient storage temperatures. (Hot/cold or Expansion/contraction). The risk of fire is always there with any battery. A smoke detector in the area may be your early warning. That’s what I did. Gives me some peace-of-mind. I also park our hybrid vehicle in the same area.

 

[emtbeast]

The worstcase scenario for ebike(lithium ion) batteries laying somewhere in a shop for months is if the battery discharged itself fully to 0% and stays there for a prolonged time.
These batteries typically self-discharge at a rate of about 5% per month, depending on the type of battery and temperature of storage space.
Generally, lithium batteries can be stored for up to 6 to 12 months without significant degradation, provided they are stored under the right conditions.

• Cool and Dry Place: Store batteries in a cool, dry place to prevent overheating and moisture damage.
• Avoid Direct Sunlight: Keep batteries away from direct sunlight to prevent them from getting too hot.
• Regular Checks: Every few months, check the battery’s charge level and recharge it to 50-60% if necessary.

Important note to add: A fully charged batteries are also exposed to higher degradation because of storage at full charge for a prolonged time.

It is all about how good the chosen bike shop personell is trained/knowledgeable and professional about it.

I would ask the shop at first contact to:
1. show me at what state of charge the chosen bikes battery is, 50 to 60% is what you are aiming at.
2. make a battery test and give me a written proof of the results.

More information about lithium ion batteries can be found in the attached link.

What Happens if Li Batteries Are Not Used for a Long Time?

Learn how to store and maintain lithium batteries to keep them in top condition, even when not in use. Discover tips for avoiding common storage issues.

www.ufinebattery.com

 

[erider1]

It is all about how good the chosen bike shop personell is trained/knowledgeable and professional about it.

I would ask the shop at first contact to:
1. show me at what state of charge the chosen bikes battery is, 50 to 60% is what you are aiming at.
2. make a battery test and give me a written proof of the results.

That would be great to do that.. to test the batt. when the bike arrives first time in the store... see the voltage (% of charge)
I guess sometimes it might be possible if bike was not assembled yet and store understands your concerns.

Most bikes likely sit with manufacturers in the warehouse, where all these 10k bikes have been for several years until they started discounting them... and people started showing interest....most shops likely have no idea of the battery condition and no involvement in the state of battery but still would like to make the sale... will those be objective and stand on your side?? To be seen...
I guess the process of passivation might be one of the few hopes here...
And possible warranty as well, unless there is that clause about the date of manufacture with all the bike and battery manufacturers...

 

[E-MAD MALC]

I haven’t seen or heard of a Bosch battery failure in my circle. (12+ bikes).My Bosch 625wh battery is 5 years old. The QC on these batteries seems to be fairly good. I charge almost daily …and the lowest full charge I’ve seen has been 98%, but mostly 100%.

IMO the biggest culprit for battery failures is extreme changes in ambient storage temperatures. (Hot/cold or Expansion/contraction). The risk of fire is always there with any battery. A smoke detector in the area may be your early warning. That’s what I did. Gives me some peace-of-mind. I also park our hybrid vehicle in the same area.

I'm the same as you in regards too the 500wh & 625 wh Bosch batteries not had any problems

 

[ebsocalmtb]

Many ebikes have batteries that are nearly dead flat at 0% or close to that when they are shipped to the bike shop. I do not know why, but I've helped my LBS assemble bikes from time to time, many of the ebikes come out of the box flat. This is pretty much universal across all brands that my LBS sells, with a few being slightly better then the others. (Santacruz, Pivot, Orbea, Giant, Norco, Scor, Scott and a few more)

I recall when a bunch of orbea rs range extenders came in, they were all flat dead and half of them were shot. Needless to say, this is a valid question to ask. The good news, is that in my experience overly discharged cells are a go-nogo proposition. One/Some/Many cells in the pack are below minimum charge voltage or the pack is substantially out of balance and it doesn't work, or it does work and it's fine. Said another way, if you get a bike, and the battery works, safe to assume that the storage was not an issue and won't become an issue later.

If you have a good LBS, they are checking this before the sale and are maintaining a reasonable state of charge 40-60% for the bikes that are in their possession and on the floor.

 

[Kingerz]

They are dormant when made and the deal has to activate them. A bigger problem is bikes that have been activated and sat around in shops for years: there's lot of 2023 stock knocking around.

 

[E-MAD MALC]

They are dormant when made and the deal has to activate them. A bigger problem is bikes that have been activated and sat around in shops for years: there's lot of 2023 stock knocking around.

Many ebikes have batteries that are nearly dead flat at 0% or close to that when they are shipped to the bike shop. I do not know why, but I've helped my LBS assemble bikes from time to time, many of the ebikes come out of the box flat. This is pretty much universal across all brands that my LBS sells, with a few being slightly better then the others. (Santacruz, Pivot, Orbea, Giant, Norco, Scor, Scott and a few more)

I recall when a bunch of orbea rs range extenders came in, they were all flat dead and half of them were shot. Needless to say, this is a valid question to ask. The good news, is that in my experience overly discharged cells are a go-nogo proposition. One/Some/Many cells in the pack are below minimum charge voltage or the pack is substantially out of balance and it doesn't work, or it does work and it's fine. Said another way, if you get a bike, and the battery works, safe to assume that the storage was not an issue and won't become an issue later.

If you have a good LBS, they are checking this before the sale and are maintaining a reasonable state of charge 40-60% for the bikes that are in their possession and on the floor.

 

[E-MAD MALC]

I suppose it's being less proned to creating a hazard being flat
I thought the batteries degraded by the amount of charges it's had
500 full charges and 1000 if only half charges, I thought that's the reason when taking it out the bike to store it to prolong the life of it if your not going to use for a while

 

[cream]

When brand new cells are manufactured, the building process creates a passivation layer that protects the battery from excess self discharge and is only overcome when the battery starts being used properly, ie charged and discharged.

Can you share the source of this information? As far as I know, passivation layer is only present on Primary Li ion batteries (eg. non rechargeable).

Assuming 18650 cells have that from the factory, when they reach battery pack manufacturer, they are tested for capacity by means of charge/discharge/balance test before going to the bike manufacturer.

At any rate, if the battery had proper charge level during storage, I would say it won't degrade more than 4-5% in 2-3 years. If the bike is at a discounted price, I could live with that.

Once bought, I would say that the battery life is user responsibility. So all of you should make the due diligence on how to properly use a Li ion battery...

We can start with this :

-Don't store it at 100% or <20%. Ideally 40-60%. Make a complete cycle at least twice /year.

Some cell chemistries (LG MJ1) would temporarily add internal resistance when charging after for a long storage time and will heatup on first charge. That won't happen at the same rate in all the cells of the battery pack. Heat means energy, so the cells that heat more than the others, will have less energy which will create a voltage difference between them. That would dramatically affect the available capacity of the battery pack because of how BMS is designed work.

-On low ambient temperatures, let the battery warm up before charging, especially if charging from a low state of charge (<15%)
-no high pressure water jet on battery and motor
-Use original equipment chargers (I've seen a lot of Bosch battery packs with electronics damage from external cause)

On magnetic charging/discharging connectors (eg. Specialized) check that there are no metallic debris on battery connector or on the charger connector. Being magnetic, it's easy to pick metallic parts that can short the connections or prevent the connections from being made. Check that every time.

 

[Tooks]

Can you share the source of this information? As far as I know, passivation layer is only present on Primary Li ion batteries (eg. non rechargeable).

Assuming 18650 cells have that from the factory, when they reach battery pack manufacturer, they are tested for capacity by means of charge/discharge/balance test before going to the bike manufacturer.

At any rate, if the battery had proper charge level during storage, I would say it won't degrade more than 4-5% in 2-3 years. If the bike is at a discounted price, I could live with that.

It’s a professional interest from my work, aviation based so very specialised, but applicable to lithium cell manufacture in general. A lot of our packs are rechargeable but have a long shelf life before first use.

What you said in the rest of your post is good advice, Passivation layers can reform if a battery is left unused for a long time so using them is a good idea! Long term storage of a used battery pack in itself shouldn’t usually be a problem but gives the BMS a job to do over the next few cycles. As I’m sure you know, not every BMS is the same though, but most of the big brands with properly tested and accredited battery packs should be fine.