Booster/Jumper cable procedure from Yamaha

[BumbleBee255]

Has anyone read the dead battery jumping procedure in a yamaha owners manual? Seems a little crazy to me. It states to use both a booster battery AND jumper cables. Is this all in an attempt to prevent a spark?? Most booster packs have an on/off switch that prevents any sparks when attaching. Am I reading too much into this?

 

[Neutron]

Has anyone read the dead battery jumping procedure in a yamaha owners manual? Seems a little crazy to me. It states to use both a booster battery AND jumper cables. Is this all in an attempt to prevent a spark?? Most booster packs have an on/off switch that prevents any sparks when attaching. Am I reading too much into this?

I wouldn't worry about it much, just make sure you open the engine compartment and battery compartment for a bit to ventilate