I've had the same three LG H2 3000mAh 18650s in a DNA200 Wismic Reuleaux since I got it in July 2016, so about 17 months! FYI, I rotated them only once but that was after about a year of purposely not rotating them because I wanted to test their voltages to make sure the DNA board was indeed perfectly balance charging them for safety = I tested with a ~$500 analog meter and a cheap digital meter and they were all the same voltages. (what helps make it sort of unnecessary to rotate them though is that I don't vape at high wattage, I do like .12 coils at 55-65 watts. I heard if you vape high wattage, the "first" battery may take the brunt of the force and need rotating, otherwise you may end up with unbalanced, unsafe difference in voltages). anyway, just wanted to note that when it works, the DNA is really good at balance charging, possibly better than the "safest" external chargers like Xtar and nitecore, both of which I've had problems with! I definitely noticed the past month or so it doesn't hold a charge for long at all. I charged it overnight last night and noticed today it says only %14 battery life instead of %100 and the Amps being supplied by the USB wall adapter is showing 0.00Amps which is something I set in escribe to show on the main screen while charging. The DNA200 board can charge a 1.00A with a 1A+ wall adapter, so usually it'll say around 0.90A when the battery % is as low as %14, and then it tapers down to a lower Amps being supplied as the battery fills up. I tried multiple adapters and usb cords and wall outlets and car chargers, all which work with cell phone but show 0.00A being fed to charge the MOD. I took all the batteries out to clean and it was already clean. I connect to escibe and it finds the mod as DNA200, so the USB isn't totally fried, but maybe just the charging circuit. I successfully did charge these three cells in an external and then put in MOD and it says %100 and have been vaping it for hours no problem except it still shows like %85 but 0.00A. I have escribe set to charge them to only 4.1 instead of 4.2 which the external does. I have two brand new fully charged (used an external) VTC6s for a dual 18650 DNA250 MOD that's arriving any day now and also a new fully charged LG H2 for a single 18650 DNA75 arriving any day now. Would it be a terrible idea to put these miss match cells in the MOD to check for charging? I can wait though because I just ordered three new Samsung 30Q 18650s just to test this MOD. When I get those Samsung 30Q, should I fully charge them first in an external or just put them in the MOD and USB charge check? So if all fails, then I guess the charging part of the chip fried. Is it safe to still use it if I use an external charger? What do you think caused this? Just bad luck, or was it caused by the batteries being used for 17 months? I figured I can just keep using them as long as they charged somewhat even if the charge doesn't hold for long. Thanks in advance.