In EU, '18 came fitted with li ion battery, skyrich, made in china. Brand can also be bought as original spare part for KTM.
'19 model came fitted with larger capacity skyrich, model HJTZ7S-FPZ - 240A.
If in doubt, replace wires with 10mm2.
Also replace bendix cover with rieju unit with bearings.
While at it, weld bendix and gear as per that video.
https://www.youtube.com/watch?v=CXXjFw9ghDE
If starter goes south, freely use KTM replica from aliexpress, reverse polarity.
Do all those mods, not just few. It is a best bet for longevity.
Always kick cold bike, and e start when hot. Manual says so too for a reason.
24V system, for my liking too much complication and not addressing primary issues, unless mods are carried out.
With all mods and correct battery, bike starts like crazy.