lose power when trying to start

[dommerz75]

When i put the key to on position gas needles moves and lights come on, as soon as squeeze the break to hit the start button gas needle drops and lights go off. Sometimes when let go of break goes back up and lights on, other times no changes. If give moment will power back on and wil start. Couple times if kick started fixed right away. Is it a battery issue? Loose connection? Want idea before take to shop.

Thank you