Should I leave the battery charger connected to the battery over the winter or when I’m not using the motorbike?
OK, so it’s the end of the biking season. Your pride and joy is in the garage, shed or garden and you want to keep the battery topped up and ready for next year…..
If you have a motorbike battery charger, even one of the long term battery charger/maintainers it’s not a good idea to leave it connected for long periods while the bikes not being used.
If the motorcycle or scooter is still being used once a week or so (for journeys over 15 miles), you probably won’t need to charge the battery up or keep it connected to a charger as the journey should keep the battery topped up.
If you are planning on leaving the bike for a long period (over a month), the best way to maintain the battery is to disconnect it from the bikes electrical system and charge it once a fortnight for 6 to 12 hours or so.
If the battery has to stay connected to the bike (e.g. to power an alarm etc), charge it every 10 days for about 12 hours to keep it ticking over.
Unfortunately, although most ‘Intelligent battery chargers’ are advertised as fine for being left connected to the battery for long periods this can sometimes damage a motorcycle battery.
The reason damage can occur is because although motorcycle battery optimisers do monitor the charge in the battery and reduce the charge when the battery is fully charged, most battery chargers still charge the battery (although at a much lower rate) and over time this can lead to the battery being overcharged.
Source: Motorcycle battery FAQ’s