So I've been using my new eLeaf iStick pico for a few days now and, so far, I love it. It works great. I have two separate 18650s that I charge in an external charger and drop into the mod. As of last night, I've noticed that, even when the batteries are fully charged, the mod will give a weak battery warning when firing. I also noticed that the vapor production seems fairly less significant than what it was when I first started using the mod. I have been using .1 ohm Ni200 coils for TC. When the device is in TC mode, it just goes to 75 watts, the max. But with the weak battery, it just adjusts down. According to bypass mode on the mod, the battery voltage is 4.09 volts. This specific battery is 3200 mAh and 40 amps. And both this battery and my other battery (2500 mAh, 35 amps) have this issue. What's going on here? How can I get that full power back?