Mazda MX-30 2020 Owner's Manual page 505

If Trouble Arises
Depleted Lead-acid Battery
Keep all flames and sparks away from open lead-acid battery cells because
hydrogen gas is produced from open lead-acid battery cells while charging the
lead-acid battery or adding lead-acid battery fluid:
Flames and sparks near open lead-acid battery cells are dangerous. Hydrogen gas,
produced during normal lead-acid battery operation, could ignite and cause the
lead-acid battery to explode. An exploding lead-acid battery can cause serious burns
and injuries. Keep all flames including cigarettes and sparks away from open
lead-acid battery cells.
Do not jump-start a frozen lead-acid battery or one with a low fluid level:
Jump-starting a frozen lead-acid battery or one with a low fluid level is dangerous. It
may rupture or explode, causing serious injury.
Connect the negative lead to a good ground point away from the lead-acid
battery:
Connecting the end of the second jumper lead to the negative (–) terminal of the
depleted lead-acid battery is dangerous.
A spark could cause the gas around the lead-acid battery to explode and injure
someone.
Route the jumper leads away from parts that will be moving:
Connecting a jumper lead near or to moving part (cooling fans) is dangerous. The
lead could get caught when the EV system starts and cause serious injury.
CAUTION
Connect the booster leads with extreme care.
Do not jump-start the vehicle with the charging lead connected to your vehicle.
Otherwise, the vehicle could be damaged.
Do not use your vehicle as a booster vehicle.
NOTE
If your lead-acid battery is depleted, make sure that the booster vehicle's battery is
a lead-acid battery.
1. Move the booster vehicle so that its lead-acid battery is as close as possible to
your vehicle's lead-acid battery.
2. Make sure that the power switch is switched OFF.
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