yes it is, the circuit can handle the voltage.
(the heads of 2T and 1T are the same, input voltage from 0.9 to 4 V)
BUT
MY L1T and MY 14500 did not fit together. The batt was too long and I had to insert a small copper ring into the body to make them work together.
You can look for previous threads on the same subject matter and see what experiences others had using it their L1T/L2T. As for me, there was no difference between the low and high levels, so I just use cr123s (small form factor).
