There are chemistries that are less volatile But they’re less energy dense as well.
The biggest problem I see on most of the Chinese stuff is a lack of safety in the battery packs. They’re just mass-producing cells and shoving them together, It wouldn’t be very expensive to put a small battery management system on every cell. Watch each cell for voltage and temperature. Have them shut down when they’re out of safety margins
LiFePO4 is still superior to traction lead-acid in pretty much every way: energy density, safety, time and cycle life, internal resistance… Yes, they need a BMS but those are very cheap and lots of batteries have them built-in. In fact, I was unable to find 4-cell packs without a BMS inside so I could put two of them in series and balance the 8S cells with each other using an active BMS of my choice, and ended up ordering individual cells and screwing them together.
Also worth mentioning LiFePO4 is like half the weight of lead acid and it’s far less susceptible to voltage sag under load. The only area I think LiFePO4 runs into challenges is the inability to charge below freezing. Lead acid is a real workhorse when it comes to the extremes.
IIRC there is already an e-scooter you can buy that has a sodium ion battery. From a chinese company (ofc) that I forget the name of. It touts fast charging and basically performs just fin down to -20C.
Fun fact: it would not be classified as a e-bike nor a moped in Estonia because it’s less than 1000w and max speed is no more than 25 km/h, but an mini-moped, which doesn’t need a license to drive, but you have to be older than 16 and need to wear at least a bicycle helmet.
This is big news. Why isn’t everyone already talking about SIBs? Also, the 145 Wh/kg sits neatly between LFP and NMC. As long as the other properties are reasonable, it should stand a chance against NMC.
If you need to charge LiFePO4 batteries below freezing, you can add a heater to the pack. There are even some batteries available now with built in heaters that come on automatically below freezing.
Less than half in my experience. I bought two 100ah 12v lifepos and they are under 30 lbs. 23lbs I believe. I have a lead acid deep cycle of the same power and it’s like 80-90.
I mean there are quite many fires in China started by those e-bikes but I thought it was because of bad quality.
There are chemistries that are less volatile But they’re less energy dense as well.
The biggest problem I see on most of the Chinese stuff is a lack of safety in the battery packs. They’re just mass-producing cells and shoving them together, It wouldn’t be very expensive to put a small battery management system on every cell. Watch each cell for voltage and temperature. Have them shut down when they’re out of safety margins
LiFePO4 is still superior to traction lead-acid in pretty much every way: energy density, safety, time and cycle life, internal resistance… Yes, they need a BMS but those are very cheap and lots of batteries have them built-in. In fact, I was unable to find 4-cell packs without a BMS inside so I could put two of them in series and balance the 8S cells with each other using an active BMS of my choice, and ended up ordering individual cells and screwing them together.
Also worth mentioning LiFePO4 is like half the weight of lead acid and it’s far less susceptible to voltage sag under load. The only area I think LiFePO4 runs into challenges is the inability to charge below freezing. Lead acid is a real workhorse when it comes to the extremes.
The article also mentions sodium ion batteries as an alternative. Can’t wait to see how they perform in real life.
IIRC there is already an e-scooter you can buy that has a sodium ion battery. From a chinese company (ofc) that I forget the name of. It touts fast charging and basically performs just fin down to -20C.
This one maybe?
They’re from $450 to $590, so amazingly priced.
Fun fact: it would not be classified as a e-bike nor a moped in Estonia because it’s less than 1000w and max speed is no more than 25 km/h, but an mini-moped, which doesn’t need a license to drive, but you have to be older than 16 and need to wear at least a bicycle helmet.
This is big news. Why isn’t everyone already talking about SIBs? Also, the 145 Wh/kg sits neatly between LFP and NMC. As long as the other properties are reasonable, it should stand a chance against NMC.
Bestonia
If you need to charge LiFePO4 batteries below freezing, you can add a heater to the pack. There are even some batteries available now with built in heaters that come on automatically below freezing.
Less than half in my experience. I bought two 100ah 12v lifepos and they are under 30 lbs. 23lbs I believe. I have a lead acid deep cycle of the same power and it’s like 80-90.
From what i know the issue seems to be too lax safety margins in packaging, to increase density.
Thermal runaway probably shouldn’t be a realistic consequence of bad quality in any consumer product.