I agree with your point about the chemistry, Pale Rider, barely differing in 10 years, but something must have changed to allow the very tidy in-frame systems* nowadays. Either the batteries are getting smaller, or the packaging/electronics is shrinking, otherwise we would have had in-frame systems in 2010 in
Halfords. Or maybe it's the frames that have changed?
Thoughts?
*Fazua and ebikemotion in particular
Both Fazua and ebikemotion have 250wh capacity batteries.
They are approximately half the physical size and weight of the 500wh batteries fitted to Bosch and most other ebikes.
In other words, there are half the number of penlight cells in Fazua and ebikemotion batteries, making them easier to blend into a frame.
Both those systems can manage on a smaller battery because they use lower power motors, which are aimed at fitter and lighter riders.
The key measure is energy density - the amount of grunt you can get out of a given volume of battery material.
That has improved in 10 years, but only marginally so.
In other words, a 500wh pack produced in 2010 would be ever so slightly bigger and heavier than one produced in 2020, but you would need a scale measuring grams to notice the difference.
As with the weather, past performance is a good guide to the future, so it's reasonable to predict density for lithium ion will continue to improve at a glacial pace.
Did you watch Tesla's battery announcement in September. Tab-less terminal batteries, million mile life expectancy and bonded cell to body instead of separate battery packs. Tesla are ahead in battery tech to everyone else
current-ly
Any announcement from Tesla must come with a Musk warning.
He was deliberately sketchy but encouraging about battery plans in order to keep the stock price of Tesla high - they lose money on car sales as I'm sure you know.
I'm not having a go at the bloke, there are fewer more skilled entrepreneurs, but what does Tesla actually have for sale to customers?
Electric cars powered by lithium ion Panasonic cells, which you or I could buy (you did, if memory serves).
Musk is building a cell factory, which last I heard was up and running, albeit at a low capacity.
Its focus is on lithium ion, although Musk has made a few non-specific remarks about incorporating graphene, leading (no doubt deliberately) to more excited rumours and hikes in the share price.