Get a new battery, Auto parts stores sell them.
As long as the battery in the lawnmower is a 12 Volt battery you will be fine.
Loss of power and hard to start.
Not on a push mower that has no electric start. On a riding mower, yes there is an ignition key.
i guess because it won/t start again
Dead battery and/or alternator.
If the car won't start it is usually the battery, starter or could be the altenator. What are the symptoms when you try to start it, is there any power?
The engine floods and you have to wait for the lawnmower to drain before you start it up again or it might start smoking.
Are your battery cable connections clean and tight ?
plug it in and push the on button
bad battery, and bad alternator not keeping it charged - also bad connections to the battery or loose wire connections on the alternator.
Test battery with a load tester. If battery passes you have a problem with connections or cables.
The security light has a faulty fuse and needs replaced. The vehicle not starting unless boosted means the battery has a dead cell in it .