[AlanHo]

I have been under the mistaken impression that the starter motor generator was powered from the small 12V battery in the boot. However, after accessing the KIA service manual on the internet – I can see I was wrong. It is powered via a small invertor from the high voltage hybrid battery. This is the link to the website

Kia Niro 2017 (DE HEV) Service Manual

The website has a link to download the complete pdf version but my anti-malware software flags up a warning that it is not advisable – so I have only browsed it via the safe website.

This is a diagram taken from the service manual that shows the various power flows. The HSG in the diagram is the hybrid starter generator.