I had a older original marcum vx1 that still running with no repairs over 10 years or so and my bud is still running it.. but my newer vx1 pros all went bad,same wih the newer model lx3tc.must of had a bad run of marcums on the newer models.idk.however my old vexilar fl8 is going on 15 years with the same battery and works still.never tried a bird yet.