Factory Sealed Maintenance Free batteries are very convenient to the point that all that needs to be done is put the battery into your vehicle and you are ready to ride. The only downside of this type of battery is that all batteries once activated have a shelf life, and if this battery is not going to be used right away, or be put in a vehicle that is not going to ridden on a regular basis, the battery will need to be kept charged on a battery maintainer. Power Sonic Maintenance Free Factory Activated Batteries have been filled with acid and charged at the factory. We recommend you charge these batteries prior to first use. Best battery for those who dont want to worry about adding acid. Just replace and start riding. Tough. Reliable. Whether you ride daily, seasonally, or just on weekends, you'll get more enjoyment out of your motorcycle, ATV, PWC or snowmobile with a Power Sonic battery.