@macgajster to ten model. Czyli albo źle rozumiałem, albo na YT wprowadzili w błąd:
"The circuit inside the battery works as a solenoid to get direkt power to the electric starter when you press the starter switch. The "solenoid" inside the battery only opens for a short time and the engine cant start. The starter only clicks for several minutes and suddenly it gives sufficient power to start the engine. It works like that for a period and after some month it wont start anymore. It will just continue clicking. This seems to be a very common problem with Instart. My brother have the same problem with his Instart clipper after using it for about one season. A new battery costs about 100€. Its too much. I have disassembled the battery case and found out that it is still possible to use the battery and direct start with it without using the start button. I solded a short cable between + and BV+. They are situated about 10 mm from each other. You can also link a cable to a press button outside the battery pack. I found out that it was best to take away the locking mekanism on the battery to get space for the cable. If you just solded between the + and BV+ you must take away the looking mekanism because the engine will start directly when you put in the battery, so you must take the battery away at once when it has started. Good luck"
https://www.youtube.com/watch?v=End-uEZEEAg&lc=UgxDkUzM916-n4CAZ_x4AaABAg