That’s not how it works. The 10A rating for the GA is the maximum safe continuous discharge current for the battery as rated by the manufacturer. It’s a safe operating limit, not the maximum possible current. A dead short would produce many times that current, probably until the cell got hot enough to be limited by its internal PTC thermistor, or until gas is produced, triggering the current interrupt device and permanently disabling the cell. If you’re unlucky, neither happens and it enters thermal runaway and explodes.
Current through a FET driver light is determined by three things:
- The forward voltage curve of the LED. Here’s a test of the 219B R9080 with a forward voltage plot. Note the peak output of 700 lumens occurs at 4.0A, well in excess of the rated maximum, which requires 3.3V.
- The resistance of the circuit, including any springs, leads, traces, and the FET itself.
- The internal resistance and resulting voltage sag of the battery.
If the actual current is 10A or less, which seems likely with 219Bs and a GA in this light based on my experience with other FET driver lights, it will be fine. Most LEDs can take far more current than they’re rated for without acute damage, but with more than 3.0A per 219B, almost all the energy goes in to producing heat rather than light.