Mazda MX-5 Owner's Manual page 515

If Trouble Arises
Battery Runs Out
CAUTION
Use only a 12 V booster system. You can damage a 12 V starter, ignition system, and other
electrical parts beyond repair with a 24 V power supply (two 12 V batteries in series or a
24 V motor generator set).
Jumper leads
Discharged battery
Booster battery
7–21