3 ms·

I’m most excited not about the cars, but about all of the battery factories (hopefully) being spun up to meet the demand. 18650s are still relatively pricy and

I’m most excited not about the cars, but about all of the battery factories (hopefully) being spun up to meet the demand. 18650s are still relatively pricy and challenging to get cheaply without risk of a scam. Once the price-per-cell drops we can see all kinds of great innovations with batteries. There’s some really cool easyEDA projects being designed that will let anyone build a power wall for their home. The biggest cost factor is always the batteries.

walrus01 8y ago
As a low quantity benchmark, for building small to mid size UAV battery packs, I am seeing the Panasonic NCR18650GA in small quantities for between $4.50 to $5.00 per cell. From battery vendors I can trust to not be shipping counterfeits. It's a 3500mAh 10A discharge rated cell. https://www.orbtronic.com/content/Datasheet-specs-Sanyo-Panasonic-NCR18650GA-3500mah.pdf https://www.orbtronic.com/content/Datasheet-specs-Sanyo-Pana... I have seen unsubstantiated claims that Tesla now has the cost for the Model 3 battery pack below $100 per kWh. The details of which they're obviously not going to give out for competitive reasons, though some rough estimates might find their way into quarterly and yearly SEC reports, earnings phone calls with investors, etc. The interesting thing for me about electric cars is that a lot of the "car" part is sort of a solved problem. A Tesla Model 3 or a Bolt or equivalent are a totally acceptable small to mid size car. The manufacturers of these don't need to do a lot of further development of the car to make it a good product. What they need, and are counting on, is global economies of scale to bring down the cost of building the battery pack of the car, so that they can incorporate those lower costs (and greater mAh stored per cell) advancements into their product, and then sell it to the consumer. I have no doubt that in ten years from now 21700 format cells will be significantly less costly in $ per kWh stored, and will have a greater Wh per kilogram and Wh per cubic cm/volume ratio.
- baybal2 8y ago
  On that front no small cylindrical cells can beat "brick" prismatic cells, they are the only ones which can be realistically expected to beat $100 without material costs going down, in fact, they do so already. Though... manufacturing of big prismatic cells never took off anywhere except for China.
  - dev_dull 8y ago
    I haven’t seen a hobbyist with a large project use anything other than cylindrical cells. Packs seem more geared towards RC etc. at least from my perspective we’re a long ways away from packs being a better value.
    - walrus01 8y ago
      lipo are pretty much all prismatic/pouch type cells, and used for RC/UAV applications that need high amperage draw. nissan leaf batteries are prismatic flat type. not sure who actually makes them.
- dev_dull 8y ago
  Where do you buy the NCR18650GA cells?
  - walrus01 8y ago
    https://www.imrbatteries.com/sanyo-ncr18650ga-3500mah-10a-flat-top-battery/ https://www.imrbatteries.com/sanyo-ncr18650ga-3500mah-10a-fl... note these are really not the best cells for general use, they're the best for UAV applications where Wh/kg is really important. These have a rather limited cycle life compared to lower capacity batteries in the 3000mAh range, which are rated at 5A to 8A discharge, that will not suffer as much amp-hour-capacity degradation after 400-500 cycles.

walrus01 8y ago

As a low quantity benchmark, for building small to mid size UAV battery packs, I am seeing the Panasonic NCR18650GA in small quantities for between $4.50 to $5.00 per cell. From battery vendors I can trust to not be shipping counterfeits. It's a 3500mAh 10A discharge rated cell. https://www.orbtronic.com/content/Datasheet-specs-Sanyo-Panasonic-NCR18650GA-3500mah.pdf https://www.orbtronic.com/content/Datasheet-specs-Sanyo-Pana... I have seen unsubstantiated claims that Tesla now has the cost for the Model 3 battery pack below $100 per kWh. The details of which they're obviously not going to give out for competitive reasons, though some rough estimates might find their way into quarterly and yearly SEC reports, earnings phone calls with investors, etc. The interesting thing for me about electric cars is that a lot of the "car" part is sort of a solved problem. A Tesla Model 3 or a Bolt or equivalent are a totally acceptable small to mid size car. The manufacturers of these don't need to do a lot of further development of the car to make it a good product. What they need, and are counting on, is global economies of scale to bring down the cost of building the battery pack of the car, so that they can incorporate those lower costs (and greater mAh stored per cell) advancements into their product, and then sell it to the consumer. I have no doubt that in ten years from now 21700 format cells will be significantly less costly in $ per kWh stored, and will have a greater Wh per kilogram and Wh per cubic cm/volume ratio.

baybal2 8y ago
On that front no small cylindrical cells can beat "brick" prismatic cells, they are the only ones which can be realistically expected to beat $100 without material costs going down, in fact, they do so already. Though... manufacturing of big prismatic cells never took off anywhere except for China.
- dev_dull 8y ago
  I haven’t seen a hobbyist with a large project use anything other than cylindrical cells. Packs seem more geared towards RC etc. at least from my perspective we’re a long ways away from packs being a better value.
  - walrus01 8y ago
    lipo are pretty much all prismatic/pouch type cells, and used for RC/UAV applications that need high amperage draw. nissan leaf batteries are prismatic flat type. not sure who actually makes them.
dev_dull 8y ago
Where do you buy the NCR18650GA cells?
- walrus01 8y ago
  https://www.imrbatteries.com/sanyo-ncr18650ga-3500mah-10a-flat-top-battery/ https://www.imrbatteries.com/sanyo-ncr18650ga-3500mah-10a-fl... note these are really not the best cells for general use, they're the best for UAV applications where Wh/kg is really important. These have a rather limited cycle life compared to lower capacity batteries in the 3000mAh range, which are rated at 5A to 8A discharge, that will not suffer as much amp-hour-capacity degradation after 400-500 cycles.