Ok..I did a simple experiment to test the difference between M401 and M402 batteries. Not an elaborate one but should serve the purpose well.
I prepared 2 fully charged batteries of M401/402. I made sure i puffed on each one of them alternately. Meaning that i took one puff on one and the next puff on another and so on. This makes it easier as I only wanted to know how much longer does the M401 battery lasts compared to the M402. This will also be fair on both batteries as I will not be spending more time on one battery compared to the other. Not to mention that its easier to keep count. It took a toll on me mentally though but can't blame anyone since I'm lame enough to do this....
Sure enough, the M402 started to blink first (meaning that it needs to recharge). But the real result is how much longer did the M401 battery last?
Now for some details,
Both batteries lasted me the entire day. I actually had to vape much more than usual just in case the batteries lasts till the next day and affects my calculations (i'm just bad at math). And I also wanted to get it over with sooner.
**Both batteries was vaped constantly with any breaks in between rarely lasting for more than 15-20 minutes. (Don't worry, I used low nic juice)
I started vaping at around 7.30am and the M402 started to blink at around 7.00pm. I changed a new battery for the M402 and continued the experiment. The M401 battery started to blink right after 9pm.
The results for this experiment:
M402 (7.30am to 7.00pm) = 11.5 hours divided by 2 = 5.75 hours*
M401 (7.30am to 9.00pm) = 13.5 hours divided by 2 = 6.75 hours*
Conclusion: The M401 battery lasts 14.81% longer than the M402 battery.
*Normal use can yield better usage time. I just wanted to get the whole thing over with asap.
I'm no scientist. Neither am i good with numbers. Hope this experiment helps and let me know if there are any mistakes. Again, this is meant to be as simple as possible and is not meant to be an official figure of any kind.