Can you start a motorcycle with a battery tender connected？

When It’s Generally Safe:

• If it’s just maintaining the battery (i.e., in float or maintenance mode), a Battery Tender is usually safe to leave connected while starting.

• Battery Tenders are low-amperage chargers, designed more for maintenance than charging a dead battery, so they don’t interfere much with normal starting operation.

Be Cautious If:

1. The Battery Tender is actively charging a low battery — some models may not supply enough power fast enough to support a start and could be damaged or trip a safety feature.

2. You're using a high-output charger (not a typical Battery Tender) — in that case, starting the bike while it's connected could damage the charger or your bike’s electrical system.

3. The Battery Tender uses delicate electronics — a sudden voltage drop from starting could potentially damage sensitive chargers (though most modern ones are protected).

 Best Practice:

To be extra safe, disconnect the Battery Tender before starting — it only takes a few seconds and removes any risk.