Ebike battery house fire in Australia

[tomjasz]

lithium-ion battery or Li-ion battery is a type of rechargeable battery. Lithium-ion batteries are commonly used for portable electronics and electric vehicles and are growing in popularity for military and aerospace applications. Wikipedia
Nominal cell voltage: 3.6 / 3.7 / 3.8 / 3.85 V, LiFePO4 3.2 V
Energy density: 250–693 W·h/L (0.90–2.43 MJ/L)
Specific energy: 100–265 W·h/kg (0.36–0.875 MJ/kg)
Charge/discharge efficiency: 80–90%
Energy/consumer-price: 6.4 Wh/US$
Specific power: ~250 – ~340 W/kg
Lifespan: about two to three years newark.com

 

[JES2020]

I think this conversation will be a thing of the past very soon.

Everyone is rushing towards solid state battery, I don't know much about it, but isn't solid state something like x7 more energy dense than lithium ion and no risk of self combustion?

Solid state lithium batteries offer 2x as much power per same size cell and are very very much safer as far as fire is concerned,( I saw a demo where the scientist punctured and smashed and even cut into smaller and smaller pieces and not only did it not combust , or even get warm, but it still functioned!

I am charging a battery now. When I charge this type of battery I can do so with the battery switched to the off position and it charges to 90% and stops charging. I can use them at 90% for most rides or if I am going on a big ride charge the last 10% just before the ride.

Bafangs do not have a secondary motor mount and newbies are often temped to route power between the motor and the bottom bracket. And they do not know how to fully secure a BBSXX. When the motor then shifts position forward it crimps these power wires at the bottom bracket. I am not saying this was the cause of this particular fire. But shorting the power supply is not a good thing. Does the motor look like it shifted toward the downtube?

I just did the first cell balancing charge of the season and to my surprise, I went from a full battery being 54.6 to 54.9v ! Guess my battery wasn't ever balanced last season, then again I think I only did a balance charge once since I got it last year. !

 

[Gionnirocket]

Solid state lithium batteries offer 2x as much power per same size cell and are very very much safer as far as fire is concerned,( I saw a demo where the scientist punctured and smashed and even cut into smaller and smaller pieces and not only did it not combust , or even get warm, but it still functioned!

I just did the first cell balancing charge of the season and to my surprise, I went from a full battery being 54.6 to 54.9v ! Guess my battery wasn't ever balanced last season, then again I think I only did a balance charge once since I got it last year. !

I would not charge over 54.6v... and I would check this with a reliable Voltmeter.
If your setup is allowing you to, there is a problem.
Lion batteries can continue to absorb power beyond thier rated limit.. but doing so is very dangerous... If this thread hasn't made that apparent

Over Charging
Overcharging Lithium-ion
Lithium-ion operates safely within the designated operating voltages; however, the battery becomes unstable if inadvertently charged to a higher than specified voltage. Prolonged charging above 4.30V on a Li-ion designed for 4.20V/cell will plate metallic lithium on the anode. The cathode material becomes an oxidizing agent, loses stability and produces carbon dioxide (CO2). The cell pressure rises and if the charge is allowed to continue, the current interrupt device (CID) responsible for cell safety disconnects at 1,000–1,380kPa (145–200psi). Should the pressure rise further, the safety membrane on some Li-ion bursts open at about 3,450kPa (500psi) and the cell might eventually vent with flame. (See BU-304b: Making Lithium-ion Safe.)

 

[Gionnirocket]

Wouldn't BMS prevent it though? (assuming it's working, of course)

It should... So should his charger... But if there is a malfunction... Then there is a malfunction.
0.3v isn't very much across multiple cells... But you also don't gain anything, so going beyond the rated limit has way more cons than pros
I would think the bike display or whatever he used to determine the voltage is probably the weak link here and the battery charged properly

 

[tomjasz]

Lipo

Unfortunately, the market is quite confused. But you have far more experience than I.

 

[JES2020]

I would not charge over 54.6v... and I would check this with a reliable Voltmeter.
If your setup is allowing you to, there is a problem.
Lion batteries can continue to absorb power beyond thier rated limit.. but doing so is very dangerous... If this thread hasn't made that apparent

Over Charging
Overcharging Lithium-ion
Lithium-ion operates safely within the designated operating voltages; however, the battery becomes unstable if inadvertently charged to a higher than specified voltage. Prolonged charging above 4.30V on a Li-ion designed for 4.20V/cell will plate metallic lithium on the anode. The cathode material becomes an oxidizing agent, loses stability and produces carbon dioxide (CO2). The cell pressure rises and if the charge is allowed to continue, the current interrupt device (CID) responsible for cell safety disconnects at 1,000–1,380kPa (145–200psi). Should the pressure rise further, the safety membrane on some Li-ion bursts open at about 3,450kPa (500psi) and the cell might eventually vent with flame. (See BU-304b: Making Lithium-ion Safe.)

No problem here !
I always take the bike out immeadeatly after charging, Also the dentrite formation you were eluding to, (not so much plating being the issue) which happens when you keep the lions at full charge over time.
I have studied extensively on this subject and the balancing is what inproves the capasity of the pack.
keeping the cells full over time grows DENTRITES, which short out the cell .

There IS a conflice of information here !

 

[Gionnirocket]

No problem here !
I always take the bike out immeadeatly after charging, Also the dentrite formation you were eluding to, (not so much plating being the issue) which happens when you keep the lions at full charge over time.
I have studied extensively on this subject and the balancing is what inproves the capasity of the pack.
keeping the cells full over time grows DENTRITES, which short out the cell .

There IS a conflice of information here !

Enjoy

 

[JES2020]

It should... So should his charger... But if there is a malfunction... Then there is a malfunction.
.03v isn't very much across multiple cells... But you also don't gain anything, so going beyond the rated limit has way more cons than pros
I would think the bike display or whatever he used to determine the voltage is probably the weak link here and the battery charged properly

MMM, wrong again, the voltage was confirmed across both a watt meter and the display !
The charger does stop at 54.6 (light goes out) but if you leave the charger on it will cycle on again AFTER the low cell are brought into balance theyby producing the extra 03v ( which is the whole point of balancing ) !

 

[Gionnirocket]

That's why this guy left his plugged in overnight... For that .03v extra balance.

 

[Asher]

Solid state batteries are 5-10 years away.

 

[JES2020]

That's why this guy left his plugged in overnight... For that .03v extra balance.

View attachment 82356

Sheesh ! It's not for the extra .03 it's for a balanced healthy battery pack !
I assume you talked to the guy who had the fire, to know the cause????? NOPE !
Your starting to get on my nerves !

 

[Gionnirocket]

Solid state batteries are 5-10 years away.

C'mon... Can't we do an Operation Warp Speed?

 

[JES2020]

Sheesh ! It's not for the extra .03 it's for a balanced healthy battery pack !
I assume you talked to the guy who had the fire, to know the cause????? NOPE !
Your starting to get on my nerves !

Written by Anton Beck​

Why Proper Cell Balancing is Necessary In Battery Packs​

Summary​

Balancing cells is not only important for improving the performance and life cycles of the battery, it adds an element of safety to the battery.
One of the emerging technologies for enhancing battery safety and extending battery life is advanced balancing. Since new cell technologies track the amount of balancing needed by individual cells, the usable life of battery packs is increased, and overall battery safety is enhanced.

 

[Gionnirocket]

Sheesh ! It's not for the extra .03 it's for a balanced healthy battery pack !
I assume you talked to the guy who had the fire, to know the cause????? NOPE !
Your starting to get on my nerves !

Easy Jes... 0.3v is not very much and probably within the allowed margin of error
But just consider a properly operating BMS should never allow the pack to go above 54.6v. If it is malfunctioning you have no way of knowing if one cell group is stuck at 3.9v and another is pushed to 4.5v... or some combination with multiple groups. I'm not trying to give you a hard time.... I want you to be safe so just be careful.
More importantly.. What type of battery pack do you have and who is the manufacturer?
And correction in both our posts... It's 0.3v.... Not 0.03v

 

[McCorby]

Sheesh ! It's not for the extra .03 it's for a balanced healthy battery pack !
I assume you talked to the guy who had the fire, to know the cause????? NOPE !
Your starting to get on my nerves !

No one is arguing that balancing is not important. A quality/properly functioning BMS will balance the cells without charging any of the cells above 4.2V

 

[Gionnirocket]

Never mind, Toyota is already on it.

Report: Toyota set to roll out its revolutionary solid-state battery in 2021

The technology will allow EVs to recharge from zero to full in just 10 minutes

www.topgear.com.ph

Toyota's game-changing solid-state battery en route for 2021 debut

Japan's government to join forces with industry to supercharge development

asia.nikkei.com

Toyota's Solid-State Battery Prototype Is a Potential EV Game Changer

New technology brings electric cars closer to the convenience of their gas-powered counterparts.

www.motortrend.com

You're a Google Master!

 

[reed scott]

Never mind, Toyota is already on it.

Report: Toyota set to roll out its revolutionary solid-state battery in 2021

The technology will allow EVs to recharge from zero to full in just 10 minutes

www.topgear.com.ph

Toyota's game-changing solid-state battery en route for 2021 debut

Japan's government to join forces with industry to supercharge development

asia.nikkei.com

Toyota's Solid-State Battery Prototype Is a Potential EV Game Changer

New technology brings electric cars closer to the convenience of their gas-powered counterparts.

www.motortrend.com

Great news but the bike world will be somewhat behind I figure.

 

[JES2020]

Easy Jes... 0.3v is not very much and probably within the allowed margin of error
But just consider a properly operating BMS should never allow the pack to go above 54.6v. If it is malfunctioning you have no way of knowing if one cell group is stuck at 3.9v and another is pushed to 4.5v... or some combination with multiple groups. I'm not trying to give you a hard time.... I want you to be safe so just be careful.
More importantly.. What type of battery pack do you have and who is the manufacturer?
And correction in both our posts... It's 0.3v.... Not 0.03v

Actually 10% is within the margin of error.
I don't like it when people predict gloom and doom for any reason, much less when they are wrong ! that's just me !

 

[Gionnirocket]

Great news but the bike world will be somewhat behind I figure.

That will probably depend on cost and manufacturing difficulties.
If it's solid state I would ASSume both would be relatively low

 

[Dallant]

Never mind, Toyota is already on it.

Report: Toyota set to roll out its revolutionary solid-state battery in 2021

The technology will allow EVs to recharge from zero to full in just 10 minutes

www.topgear.com.ph

Toyota's game-changing solid-state battery en route for 2021 debut

Japan's government to join forces with industry to supercharge development

asia.nikkei.com

Toyota's Solid-State Battery Prototype Is a Potential EV Game Changer

New technology brings electric cars closer to the convenience of their gas-powered counterparts.

www.motortrend.com

Toyota says and is putting out news releases but where is it? What’s vehicles will it being used in? How much more expensive is it? Not even a prototype? As a 4 time Toyota hybrid owner, I’m less and less likely to believe Toyota about anything as time goes on.