Charging the battery should always be your first step when you are building or troubleshooting your saber. There are any number of issues that can occur when your battery is low. Many new builders are quick to assume something is broken when their newly constructed saber seems to be malfunctioning. There are, of course, plenty of things that can go wrong, but the heart of your saber is it's power source and your electronics need a properly functioning battery to behave properly.
Common issues from a low battery:
- crackling from the speaker
- constantly rebooting saber
- blade won't ignite
- blade ignites, but color is wrong/dim/"brown"
- blade ignites, but saber immediately shuts off
These issues are especially pronounced in power hungry pixel blades.
Keep in mind, it is possible that your charger is malfunctioning. An inexpensive multimeter is your best friend, you easily read the power level of your battery by setting it to DC Voltmeter and connecting the +/POS and -/COM/GND probes to the appropriate side of the battery.
Compared to the cost of building your wonderful noisy flashlight, the cost difference between the best 18650 you can buy and some cheap junk is truly insignificant. The battery is not the place where you should cut corners. Buy a protected cell that can output the current required by your saber. For most Star LED type sabers a 3A cell will suffice. For pixel blades you'll want a cell from a trusted brand that can output 10A.
Trusted battery brands include: The Custom Saber Shop (TCSS) and Orbtroic
Please feel free to suggest other battery related issues and trusted brands to be included here.