Why owners do it
Small parasitic drains and unsealed wiring can flatten a battery between jobs. A key isolator also makes electrical work safer.
What is involved
- Fit the isolator in the battery negative or positive lead, close to the battery.
- Mount it where it can be reached without opening the engine cover.
Typical parts
- Rotary or key battery isolator
- Battery cable and lugs
- Heat-shrink
Check before you start
- Size the isolator and cable for starter motor current.
- Some engines need a few seconds of power after shut-down; check before switching off immediately.