Honda CRF230F 2004 Owner's Manual page 124

Battery
We recommend using a ''trickle'' charger ( ) 1
for home charging. These units can be left
connected for long periods without risking
damage to the battery. However, do not
intentionally leave the charger connected
longer than the time period recommended in
the charger's instructions.
Avoid using an automotive-type battery
charger. An automotive charger can overheat a
motorcycle battery and cause permanent
damage.
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Servicing Your Honda