What battery pack that I can buy right now is 300Wh/kg? Sincerely curious because that's 50Wh/kg above what people are using in some very expensive UAVs.
The design of a battery for a phone is nowhere near the capability of C rate and discharge amperage needed to power multi hundred watt load electric motors. Totally different thing.
Battery people keep comparing apples, and oranges.
Battery pack energy density, battery, single cell, cathode, and their rated, nominal, and absolute capacity are all different things.
A single cell will always have > absolute capacity than the capacity at which the safety limiter will cut-off charging, and that will be > than the capacity to which BMS will charge/discharge the cell in daily use.
It may well be possible for a cathode material to excel in a small pouch cell, but have terrible thermals preventing its use in larger cells.
Very expensive UAVs use lithium polymer battery packs with continuous discharge rates on the order of 80C and above. To get higher energy density, look for lithium ion battery packs or lipo packs that reduce discharge rates to trade off for long-term storage capacity.
Compare to the discharge rate vs. energy density tradeoffs of plug-in hybrid EVs versus battery-only EVs: A Chevy Volt PHeV has a 16 kWh pack and 87 kW motor, a Chevy Bolt has a 65 kWh pack and not a 65/16x87=350 kW motor but 149 kW.
UAVs also have higher current requirement, and that means more weight "wasted" for chonkier electrodes Car batteries aren't pulling 50C worth of current
Traditional ICE starter batteries are optimized for this cold-cranking power rating, but they only have to deliver this for a matter of seconds before being recharged. They are not designed to deliver this continuously nor to ever be operated at low states of charge.
Conversely, a BEV traction battery has to support a wider range of loads at any charge state between its minimum and maximum charge levels, in order to have decent driving range. Like a starter motor, the BEV is not going to sustain high power output for very long, since a car only takes seconds to accelerate to legal road speeds. After that, it requires continuous output at lower power levels to maintain a cruising speed.
Even with lead-acid batteries, there are regular starter batteries and then there are deep-cycle batteries which have far less cold cranking amps but more durability when depleted to low charge states before being recharged.
The low density of lead-acid batteries is what makes them unsuitable for mobile applications. They might have 30-50 Wh/kg while various lithium ions might be 100-300 Wh/kg. And now this announcement is talking about 500 Wh/kg so 10x the best lead-acid batteries...
Most batteries that run starters are not energy dense, they're typically standard lead acid batteries.
FWIW, to provide the 225 amps (for a V8 starter motor) a Tesla car battery would only need a discharge capability of 3C (1C being around 80 amps), which is within its rated capabilities. This is also for batteries which provide higher voltages, so I'm vastly overestimating the C rate required.
C is the unit for charge/discharge rates, and is based off the capacity of the battery.
No, it is referring to what the starter motor in an ICE vehicle does. It was most likely a misunderstanding, but it is more similar in that it pulls very high loads like a drone battery does.
This person seems to be getting downvoted but they aren't totally wrong, electric car batteries are massively paralleled so that the amperage draw per cell is kept to a reasonable figure. They are confused about cranking amps to turn over an ICE vs. batteries used in all-electric cars.
The 18650 Panasonic cells used in an older Tesla model S for instance are rated at only 10A draw per cell as their nominal 1S voltage (4.20V when full).
It'll take time (maybe significant) before these batteries are available for direct purchase. The problem is demand current outstrips supply. Every high capacity battery already claimed, in tesla's case for their cars and grid storage applications.
CATL pushing this sort of capacity, though, is great news. It certainly will accelerate availability.
Read what I wrote again, I said 300Wh/kg is 50Wh/kg above what's used in expensive UAVs. There are setups out there using high amperage Panasonic cells at 250Wh/kg for 12S systems. You build a pack with 12S strings of high amperage rated Panasonic 18650 or 20700 and then parallel multiple of those strings together for large capacity (such as for something the size of a freefly alta X).
A small quadcopter that uses a gensace/Tattu 1200 mAh lipo pack is not an expensive uav. I think everyone who uses hobby size lipo knows their specs around 135-160Wh/kg.
