Supernova, a French company about to be launched in December 2019, has tested and opted for a ground braking battery technology called LTO (Lithium Titanate Oxyde) or lithium titanate. Here we can talk about the pros and cons of such batteries that look really promising.
More info: https://en.wikipedia.org/wiki/Lithium-titanate_battery - Toshiba LTO technology is called SCiB.
A good information site (2015 though): https://www.eetimes.com/author.asp?section_id=36&doc_id=1325358. This article in its comment area introduces the ‘burn rate’ definition that is completely underestimated today for current batteries:
- Li-Ion batteries have a charge cycle number commonly admitted at 300 cycles before reaching 80% of initial capacity. Cost of a charge cycle for LIFT = 3500USD retail price / 300 charge cycles= 12USD + electricity
- LiFePo batteries have a charge cycle commonly admitted at 900-1000 cycles
- LTO batteries, 5000 to 20.000 cycles depending on manufacturer figures (Leclanché 20k cycles)
The low weight / burn rate (cost of ownership) / charge time seems to make those batteries the most suited for any efoil owner especially rentals.