Honda HSM1590i Manuel De L'utilisateur page 107

When disconnecting the battery cable, be sure to disconnect at the
battery negative ( ) terminal first. To connect, connect at the positive −
( ) terminal first, then at the negative ( ) terminal. Never disconnect ＋ −
the battery cable in the reverse order, or you may cause a short circuit
if a tool contacts the positive terminal.
When you replace the battery, do it in pairs.
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