Featherweight USB Battery Charger

Battery Management 

Due to space constraints on the active bulkhead, unlike the 38mm version, the 29mm av-bay does not include a USB port for charging the battery. To charge the LiPo battery used in the av-bay, you will need to provide your own charger, or obtain a Featherweight USB Battery Charger. 

To use the Featherweight USB Battery Charger, plug the battery in to the board, the connect the USB cable to the board, and finally to either a USB port on your computer, or a USB wall wart. The LED on the board will be red while the battery is charging, and will turn orange when charging is complete. The charger takes care of charging the battery, and won't overcharge the cell unless there is a failure in the system. Because of the (remote) possibility of failure, you should take precautions when charging, such as not charging unattended or with flammable material nearby. Never charged a cell that is damaged or that has its cover puffed up. When the charger's LED turns from red to orange, the cell is fully charged. If the cell has been very discharged, it could take 1-2 hours to fully charge it. Usually the cell would start out with a higher state of charge and it would take less time than that.  

Always recharge the battery and/or measure its voltage before flight. If it's less than 4 V, a recharge is recommended. When the charger cuts off the charge and turns the LED from red to orange, the cell's open-circuit voltage should be around 4.1-4.15 V. While the LiPo battery included with the av-bay has a long life, there are limitations. The magnetic switch used to turn the av-bay on and off consumes power, even when the unit is powered down. Because of this, the av-bay should not be assembled with the battery installed for extended periods of time – a few days is fine, but more than a week will noticeably discharge the battery and is not recommended.

For more information visit the Featherweight Users Forum here