In many cases when a power tool battery fails you can use a battery from another power tool use a power tool as long as it is a similar (lower) voltage. In this case this Flymo strimmer battery has died and will no longer work, here I have taken a Milwaukee 18v battery and taped it to the strimmer then used two simple wires with spade connectors on the end. The strimmer now works like new and has saved me £65 for a new battery.