Electric Start Only Works When Motor is Running?

[marfia]

hi all
my son has a atomic and the elec start dose not work battery is charged but when he kicks it over and then pressers the start button you can hear the elec starter turn over but only when the motor is running

 

[eichkay]

Battery is sulfated, its holding a surface charge but when you go to start it loads up and drops to flat straight away.

 

[marfia]

ok i will try a different battery thanks for that