A battery tender, also known as a trickle charger, is designed to provide a slow and steady charge to a motorcycle battery to keep it charged over an extended period. It is generally safe to leave a battery tender connected to a motorcycle battery for an extended period, such as weeks or even months.
Modern battery tenders are typically designed to be left connected for long durations without causing any harm to the battery. They employ sophisticated charging algorithms that monitor the battery's charge level and adjust the charging rate accordingly. Once the battery reaches its full charge, the tender will enter a maintenance mode, delivering a very low current to keep the battery topped up without overcharging it.
Different models may have slightly different specifications and recommended usage times. Be sure to read the manual that came with your battery tender to understand its limitations and usage recommendations.
If you are unsure or have any concerns, it is always a good idea to consult the manufacturer or seek advice from a qualified professional, such as a motorcycle mechanic or battery expert. They can provide specific guidance based on your motorcycle's battery type and the battery tender you are using.