szczur333 said:
li ion is best choice - LTO has zero advantages -
It's not for everyone, but to say it has zero advantages is throwing the baby out with the bathwater.
I have a 48v 4Ah pack for my eBike. It's tiny, and just enough to get me to work 18km away, as long as I pedal.
I have a 144v 28Ah pack for my electric motorcycle project, estimating 70-100km depending on speed. Could I have fit triple the capacity using LiPo? Almost certainly. Year 1 performance would also have been much better than LTO. My cells are 10C constant, 20C burst, so triple LiPo capacity, and even a conservative 30C rating would mean that LiPo can deliver 9x more power.
Year 2+ performance though... LiPo degrades faster when packed into large batteries that don't get proper cooling. And introducing proper cooling loses only a small percentage of the weight advantages, but starts killing off the volume advantages.
There's also less of a fire risk with LTO, it has a more stable performance over a range of temps, and if your bike is a daily rider, your LTO will still be going strong after you've retired your third, fourth, fifth LiPo pack. It's not even capacity loss. LiPo suffers power density loss pretty quickly too.
If I was aiming for a 3 year life and had enough room. 18650 or 21700 with adequate cooling would be my choice. Anything longer than that, I'm using LTO.