E-Bike Battery Guide

[Ravi Kempaiah]

E-bike fires are causing havoc in the NY City. The number of E-bike fires has gone up in the last 1 year and it is extremely important that people purchase bikes that have a higher-quality battery.
A few days ago, NBC and NYTimes had reached out to my advisor at work to weigh in on the E-bike battery problems.
One of the large US companies is also involved in this ongoing issue in NYC. The NYC is now mandating that all E-bike fleets be UL certified.

How to Prevent an Electric-Bike Fire - Consumer Reports

Consumer Reports shares advice from the FDNY on keeping the lithium-ion batteries on an e-bike from overheating to prevent an electric-bike fire.

www.consumerreports.org

FDNY Issues Warning in Wake of E-Bike Battery Fires

Fire investigators issued a warning for e-bike riders Monday following an alarming pattern of battery-sparked fires in New York City. The FDNY put out photos from four fires the department says were started by lithium-ion batteries all in the past week. The recent incidents have fire officials...

www.nbcnewyork.com

 

[George S.]

E-bike fires are causing havoc in the NY City. The number of E-bike fires has gone up in the last 1 year and it is extremely important that people purchase bikes that have a higher-quality battery.
A few days ago, NBC and NYTimes had reached out to my advisor at work to weigh in on the E-bike battery problems.
One of the large US companies is also involved in this ongoing issue in NYC. The NYC is now mandating that all E-bike fleets be UL certified.

How to Prevent an Electric-Bike Fire - Consumer Reports

Consumer Reports shares advice from the FDNY on keeping the lithium-ion batteries on an e-bike from overheating to prevent an electric-bike fire.

www.consumerreports.org

FDNY Issues Warning in Wake of E-Bike Battery Fires

Fire investigators issued a warning for e-bike riders Monday following an alarming pattern of battery-sparked fires in New York City. The FDNY put out photos from four fires the department says were started by lithium-ion batteries all in the past week. The recent incidents have fire officials...

www.nbcnewyork.com

EV fires have been a problem, notably for GM. The thing is, Tesla is shifting to LFP for the lower end Tesla models. It's much less combustible, very difficult to ignite. I actually owned an ebike with an LFP battery, a Prodeco, years ago. I have made two LFP packs, and they hold their voltage exceptionally well. So I use these packs. Long cycle life, take a lot of abuse in charging. LFP is very cheap to build, mostly 32700 cells. So if it's really a problem, why not just go with LFP? Aren't the performance cells that ebike companies use to make packs inherently less safe? With such a high proportion of new cells coming out of China, I'm not sure what you are saying. What sort of pack are you describing, the quality one? Are any Chinese cells 'good enough'?

 

[Ravi Kempaiah]

EV fires have been a problem, notably for GM. The thing is, Tesla is shifting to LFP for the lower end Tesla models. It's much less combustible, very difficult to ignite. I actually owned an ebike with an LFP battery, a Prodeco, years ago. I have made two LFP packs, and they hold their voltage exceptionally well. So I use these packs. Long cycle life, take a lot of abuse in charging. LFP is very cheap to build, mostly 32700 cells. So if it's really a problem, why not just go with LFP? Aren't the performance cells that ebike companies use to make packs inherently less safe? With such a high proportion of new cells coming out of China, I'm not sure what you are saying. What sort of pack are you describing, the quality one? Are any Chinese cells 'good enough'?

China produces bottom-of-the-barrel electronic junk and they also produce top-quality iPhones and MacBooks.
It greatly depends on the company that is designing and putting these packs on the market.
We have bi-weekly calls with Tesla and we listen to them intently and they are constantly working on bringing the cost down to $100/kWh while making the packs very safe (and 8 yr warranty). Most E-bike batteries with decent BMS cost upwards of $700 for 0.6 kWh and just 1 year warranty. This is outrageous.

LFP is great for mass-market cars, not so great for E-bikes. To get adequate range on LFP, the E-bike would weigh upwards of 30kgs+ and it becomes unwieldy at that point.
As you can see from the latest paper from our lab. NMC cells can have 2x or 3x the cycle life of LFP and when amortized over time, it would be cheaper.
LFP is rated for 15-20 years, and NMC can have anywhere from 30 years to 100 years depending on the voltage window. When you recycle NMC, you get Ni and Co (which are valuable) and when an LFP cell is recycled, it has minimal value and in the battery communities, there are lots of discussions about the recyclability of LFP.
NMC can also be made very safe.

Paper link: https://iopscience.iop.org/article/10.1149/MA2021-0251893mtgabs/meta

 

[scottsdalecommuter]

China produces bottom-of-the-barrel electronic junk and they also produce top-quality iPhones and MacBooks.
It greatly depends on the company that is designing and putting these packs on the market.
We have bi-weekly calls with Tesla and we listen to them intently and they are constantly working on bringing the cost down to $100/kWh while making the packs very safe (and 8 yr warranty). Most E-bike batteries with decent BMS cost upwards of $700 for 0.6 kWh and just 1 year warranty. This is outrageous.

LFP is great for mass-market cars, not so great for E-bikes. To get adequate range on LFP, the E-bike would weigh upwards of 30kgs+ and it becomes unwieldy at that point.
As you can see from the latest paper from our lab. NMC cells can have 2x or 3x the cycle life of LFP and when amortized over time, it would be cheaper.
LFP is rated for 15-20 years, and NMC can have anywhere from 30 years to 100 years depending on the voltage window. When you recycle NMC, you get Ni and Co (which are valuable) and when an LFP cell is recycled, it has minimal value and in the battery communities, there are lots of discussions about the recyclability of LFP.
NMC can also be made very safe.

Paper link: https://iopscience.iop.org/article/10.1149/MA2021-0251893mtgabs/meta

View attachment 109390

Thanks for sharing the article, good to know and will definitely not charge bike overnight. Usually if I start it right after my evening commute it is full charge right before bed. I do like other suggestions to charge in morning before ride. I also like to charge at my desk at work because there is something soulful about my employer paying my commuter costs even though it’s like a dollar. I’ve tried to talk my wife into Tesla and the charging at home battery fire is one of her primary concerns (plus they are expensive at 50k) and I think I’d rather wait 5 years to let them work out some issues and get this new magic battery in there and see if I can’t get 500k miles on a Tesla

 

[tomjasz]

Who built the failed batteries.? Hailong shark packs stuffed with glued cells to get 52V.?

 

[mclewis1]

Who built the failed batteries.? Hailong shark packs stuffed with glued cells to get 52V.?

Tom, The video is from a scooter battery fire, so no ... but it's a good point about garbage mechanical quality being a big problem no matter what type of usage.


The ebike market demands performance (weight vs. capacity vs. price) but we currently accept some general packaging and charging limitations. Building to standards is one avenue to safer commercial products but it will increase prices (in manufacturing as well as oversight) in very price sensitive markets. Increased safety through design and different battery technologies currently seems to be the way our industry (EVs as a whole) is going but I think with the desired very low price points demanded by the scooter and low end/DIY ebike markets they will remain a concern. This might also put some of the onus for increased safety on the battery packaging manufacturers - Hailong, Reention, etc.

We do seem to be moving away from obvious add on battery technologies on commercial ebikes (things are now much more integrated) but it sure is interesting that you can buy branded battery cases and stuff them full of any DIY battery components. Then if there's a fire everyone steps back with the "that's not my fault" attitude.

In North America I can see the insurance companies pushing for battery standards and then getting home/apartment/condo owners to institute controls over the presence of non UL/CSA approved batteries. Essentially contract verbage that negates coverage if a fire is found to have been caused by a non UL/CSA approved battery.

 

[tomjasz]

Building to standards is one avenue to safer commercial products but it will increase prices (in manufacturing as well as oversight) in very price sensitive markets.

I think that’s not quite correct. See EM3ev build standards as an example. Chinese makers COULD raise the bar and still have a tidy margin.

The eBike fire that myself and others criticized UPP over had a somewhat overlooked mitigating facts. 72V battery on a BBSHD and after market controller trying to squeeze every last millivolt out of his battery.

 

[Neeko DeVinchi]

Wow!!!
This thread really does delve into ebike batteries.
I'm gonna keep a watchful eye on this thread so I can pick up some pointers.

Truth be told, I generally stick to battery designs which I'm use to. I.e. Reention Darado. But with new ebikes which I'm building, I'll need to strip one to understand where everything is to get an idea to ensure that I can keep them going for as long as possible.
I'll do my utmost to contribute to the thread but kudos to the OP for making the thread

 

[George S.]

Tom, The video is from a scooter battery fire, so no ... but it's a good point about garbage mechanical quality being a big problem no matter what type of usage.


The ebike market demands performance (weight vs. capacity vs. price) but we currently accept some general packaging and charging limitations. Building to standards is one avenue to safer commercial products but it will increase prices (in manufacturing as well as oversight) in very price sensitive markets. Increased safety through design and different battery technologies currently seems to be the way our industry (EVs as a whole) is going but I think with the desired very low price points demanded by the scooter and low end/DIY ebike markets they will remain a concern. This might also put some of the onus for increased safety on the battery packaging manufacturers - Hailong, Reention, etc.

We do seem to be moving away from obvious add on battery technologies on commercial ebikes (things are now much more integrated) but it sure is interesting that you can buy branded battery cases and stuff them full of any DIY battery components. Then if there's a fire everyone steps back with the "that's not my fault" attitude.

In North America I can see the insurance companies pushing for battery standards and then getting home/apartment/condo owners to institute controls over the presence of non UL/CSA approved batteries. Essentially contract verbage that negates coverage if a fire is found to have been caused by a non UL/CSA approved battery.

So...

1) We don't know how many fires there are, what the true failure rate is. Most fires may be without consequence.

2) We don't know what fails. Basically, there is a short circuit and thermal runaway, but that percent is that?

3) There are lithium packs in my robovac, my toothbrush, my phone, my drill, my soldering gun, my solar floodlight, my chainsaw, my jigsaw, and on and on and on. This is going to be hard to regulate, with what is out there.

It's clear that LFP is a safer chemistry. Jehu Garcia had a video. He takes an LFP cell and he short circuits it. The metal in the short gets red hot, but not a whole lot happen. You want safe? Safer.

This is a very interesting and very detailed examination of battery cell issues that lead to fires. It's clear to me the solution is with the cells. And, of course, you can go buy a safe cell, relatively safe, right now. I spent some time designing a good way to integrate my LFP into my bike. You guys are not willing to make any concessions. Ravi said it best, see below. Stop the outrage. It's not cheapo DIY'ers. It's just not. If the ebike battery cost anything like an EV battery...

Batteries and Energy Storage Technology magazine

www.bestmag.co.uk

 

[mclewis1]

I think that’s not quite correct. See EM3ev build standards as an example.

Tom, That's a good point. I should have said regulatory standards. Certainly any good quality battery manufacturer is already building to a set of standards (quality of welds, size of buss bars, shock resistant designs, "waterproofness", use of glues, etc.)

The regulatory standards dictate the presence of documentation on materials, manufacturing and testing protocols as well as some actual destructive testing (well at least they used to).

 

[tomjasz]

The regulatory standards dictate the presence of documentation on materials, manufacturing and testing protocols as well as some actual destructive testing (well at least they used to).

Indeed true but we don’t demand that our battery is UN 38.3 certified. Only 1 or maybe 2 EM3EV batteries are UN38.3. UPP? Our member Jenny Mao?

 

[6zfshdb]

These recent reports of lithium battery fires caused me to rethink the precautions I take. All my batteries contain quality Panasonic 18650 cells that I keep in my heated, attached garage. I store & charge on a metal shelf away from flammable materials. I have the chargers on a timer which I set for the estimated charge time required and don't rely on the charger cutoff circuit. The garage and house are equipped with smoke & carbon monoxide detectors. Lately, I've been looking at steel flammable storage cabinets as an added layer of protection. Is this overkill? Am I just being paranoid here?

Lithium cordless tool batteries have been around for a decade or so in the hands of hapless consumers. The number of fire related reports caused by this equipment is far less than those I see on e-bike and other hobby related lithium batteries. Is this due to use, size, cell quality or something else?

With the many thousands of posters here on EBR, has anyone PERSONALLY experienced a lithium battery fire?

 

[tomjasz]

Lately, I've been looking at steel flammable storage cabinets as an added layer of protection. Is this overkill? Am I just being paranoid here?

Lithium cordless tool batteries have been around for a decade or so in the hands of hapless consumers. The number of fire related reports caused by this equipment is far less than those I see on e-bike and other hobby related lithium batteries. Is this due to use, size, cell quality or something else?

I think that tool batteries may have better battery controllers.

I'm definitely in the safer the better club. I waited until Zoro had a sale and shipping discount and bought a safety cabinet AND large ammo can. Because I ride all winter days with dry streets I'm stuck charging indoors.

When I think of the cost of having even the smallest battery fire, the price is minimal.

 

[tomjasz]

Good information here.

And here;
"Most lithium battery fires are caused by cell-phones, vape pens, and laptop computers. It is rare to have an incident with power tools. As the lithium battery technology develops, these fires are on the decline yet they still occur. Be very careful when buying replacement batteries for any device. The vast majority of battery failures are due to shoddy-made batteries and counterfeits made in China. The most common distribution of these defective batteries are sold on websites; the most notable being Amazon."
"There are two basic types of battery failures. One occurs at a predictable interval-per-million and is connected with a design flaw involving the electrode, separator, electrolyte or processes. These defects often involve a recall to correct a discovered flaw. The more difficult failures are random events that do not point to a design flaw. It may be a stressful event like charging at sub-freezing temperature, vibration, or a fluke incident that is comparable to being hit by a meteor."

 

[Ravi Kempaiah]

These recent reports of lithium battery fires caused me to rethink the precautions I take. All my batteries contain quality Panasonic 18650 cells that I keep in my heated, attached garage. I store & charge on a metal shelf away from flammable materials. I have the chargers on a timer which I set for the estimated charge time required and don't rely on the charger cutoff circuit. The garage and house are equipped with smoke & carbon monoxide detectors. Lately, I've been looking at steel flammable storage cabinets as an added layer of protection. Is this overkill? Am I just being paranoid here?

Lithium cordless tool batteries have been around for a decade or so in the hands of hapless consumers. The number of fire related reports caused by this equipment is far less than those I see on e-bike and other hobby related lithium batteries. Is this due to use, size, cell quality or something else?

With the many thousands of posters here on EBR, has anyone PERSONALLY experienced a lithium battery fire?

I personally have seen 3 name-brand E-bike batteries catch fire.
In two cases, the company sent replacement bikes as soon as they heard the news to minimize bad PR. I find it
More than the fires, abnormal deterioration of packs is much more common.
Most cordless power tools are tested to higher standards than E-bike batteries. CSA, UL, etc. For example, Milwaukee Power Tools or Dyson only purchase cells that are of a certain quality.
The cells that did not pass the testing are sold to vaping community or other distribution channels.

 

[Ebiker01]

Most E-bike batteries with decent BMS cost upwards of $700 for 0.6 kWh and just 1 year warranty. This is outrageous.

How did they settle up on this rip off prices ? ?
Sounds like it it's a conspiracy of the major companies colluding to impose this price.

For those who don't know a 75 kW pack fo an EV car would have to cost around 80.000$ If we base our math on their ebike battery pricing.

 

[AleksR]

EV bike fires.........LOL.....another hysteria that hasnt gotten much traction nationwide except here.

 

[tomjasz]

I’m sure I paid under $400 delivered. I did stay on the hunt with Googl

EV bike fires.........LOL.....another hysteria that hasnt gotten much traction nationwide except here.

in your narrow view?

 

[AleksR]

I’m sure I paid under $400 delivered. I did stay on the hunt with Googl

in your narrow view?

Not narrow, just facts. I read many news outlets and havent seen a single article on ebike battery fires. If it does happen, it must happen at a very low frequency, that said, there is a reason you cant transport the batteries on planes. They are a greater hazard when it comes to explosions.

Fortunately and unfortunately, this is such a rapidly developing field, that many variations will be on the market, and only time will tell which brand is safer than other, but honestly, I havent seen a significant public spotlight on this issue and anecdotal stories are just that, anecdotal stories. We need big data: what is the rate of battery igniting or exploding per unit purchased.

 

[tomjasz]

facts.

Your facts. Not based in reality. The data is out there. But I guess we live in an age of alternative facts.