Hey, I don’t know a whole lot about batteries, but Tesla has bought Maxwell some time ago and is speculated to be far along in the process of building their own batteries with a new technology providing a higher energy density.
Battery day has been postponed to mid-may and I was wondering if something like that might be good news for electric paramotors in terms of flight time? (Would such batteries even be available to buy?)
1 Like
It is sort of good news, but not really.
Musk said that the batteries shown there would blow our minds which is good. Another good thing is that Tesla allows many of the other companies to use their parents to help technology to develop faster.
The bad news is that Tesla builds batteries for cars. Because of this the cells are rated for around 3c. For a paramotor we need batteries rated at least 6c and 10c is even better.
My prediction is that this technology will impact the electric car world quite a bit but I don’t think it will impact electric paramotors very much until comparable battery technologys are developed with a higher C rating. Also Tesla doesn’t sell any of their batteries so even if the batteries would be compatible with paramotors it could still take years before another company makes comparable battery that we could get our hands on.
Had to google what the c rating is.
As I understand it, a higher C-rating means higher output voltage, but also less time of continuous discharge. So why is a higher c-rating better, when you can just get a battery with bigger capacity, to provide higher voltage, while simultaniously having a longer duration of continuous discharge due to the low c rating?
These motors suck a lot of juice fast.
Our requirement is for a fairly high energy draw at launch and for a good climb rate. Probably compares to a model S in ludicrous mode in terms of energy draw/vehicle mass.
However this is constant whereas the C rating of a battery is a ratio and depends on the capacity of the battery. With 12-14 LiPo cells we need 240 amps peak and 150-160 continuous amp draw. With a battery capacity of 40 amphours (2 Bonkas in parallel is 44 amphours) the peak draw is 6X capacity or 6C. However if we had an 80 amphour battery that was about the same weight as the current 40amphour battery it would only need to be capable of 3C to meet out peak demand. You need to look at the total capacity divided by the C rate.
Yes, I hope Tesla’s new battery tech blows our minds. Even if it’s the same mass energy density in a more robust and way cheaper cell.
here is a very good video, speculating on what improvements might be made to battery life, energy density and discharge rate.
Might be worthwhile.
When designing a battery there will almost always be a trade off between power and energy density. If they can get a higher energy density it is fairly safe to assume that it will have a lower C rating then their current batteries but have a comparable amp rating. They will do this so they can get as much energy density as possible.
For sure. But we are hoping for a big improvement here not just a new trade off. Power, energy density, cycle life, cost, safety, … All must be considered for a given application.
There are used Tesla batteries sold on secondary markets.
At some point these new mind blowing batteries will be available too.
Not holding my breath…