To be honest Im not very impressed with the manual batts. I bought them a couple weeks a go and switched back to the autos. first prob is when I take a long puff they switch off. I tried double clicking the button to make it last longer. it works but its a pain in the ass. Second prob is im so used to puffing with no hands a lot of the time and you cant do that with them. If I could design them I would first have no cut off time and second have a switch to go from auto to manual. Just my two cents