If you like the 650 mAh size and if you can figure wattage without a readout, then there's no better battery than the Joyetech eGo-c upgrade batt for the longest whole life of the battery. I have several that I've had over a year. I've had Vision Spinners and knockoffs that have lasted 3-5 months.
The Joye eGo-c upgrade has the 5 click on/off, a 10 second cutoff that is actually around 13-14 seconds (Visions are usually below 8 and I had one that was closer to 6). The button led changes from white to light blue to dark blue at the end of the charge, so if you're at 'white' going out - you'll have a good 4-6 hours - ymmv depending on power vaping vs. regular use. I have around 6 pairs - two for each flavor I use, going for over a year. Two of the most used are on their last legs - I reported this earlier but they're still working - the charge cycles are now shorter than they were a few months ago.
I personally have never had a Joye batt 'lemon', but it's possible. There have been some reports on this forum of them and some reports that they were Joyes when they weren't. It happens. No eGo batts will do 'sub-ohm' well. Anything below 1.3 ohms is asking for trouble with eGo's even Joye eGos. And you can get below 1.3 ohms by using a 1.5 ohm coil and letting it get gunked up. I stay above 1.8ohm on my clearos but have used 1.5 lr Joye or cisco (also Joyes to start) attys and they work fine, but I don't use non-Joye LR attys on eGos. And I don't dry burn eGos. Not saying you couldn't, just that I don't and I don't have "battery problems". And many vendors purport to have Joyes or their blurbs invoke "Joye" in some manner but you have to make sure they're a genuine Joye vendor to be certain.
With the upgrade batt you have the best short and charge protection in the eGo style batt, and two modes -
regulated at a constant voltage for the full charge 3.4V - good for strong flavors with the 1.8 ohm Aspire or T3, evod, mini protank, and good with the 2.2 ohm coils for lighter flavors. Also has the '
unregulated mode' which runs like any unregulated 3.7V batt - 4.1-4.2V off the charger, 3.6-3.7V for most of the charge and 3.2-3.3V at the end of the charge. Turn the battery off and hold button for 8 seconds, turn back on to change modes. the 'unregulated - they call it vv because the voltage varies in that mode, but it's not true vv like the Twist - the button is orange and doesn't change colors like in the regulated mode. I use this mode occasionally if the draw tightens on darker eliquids mainly, but a coil needs cleaning or changed usually. The extra voltage helps in that case. Or sometimes I'll use that mode for a coffee flavor that likes more heat. Espresso needs the voltage of a Twist usually.
For maintenance I take a Qtip to the well of the battery connection and the charger before charging - on every charge. And I don't put a PV in the back pocket of my jeans
The threading on Joyes are the best in China, imo. And you have to get them at genuine Joye vendors - cignot, heaven gifts, are my go to shops but there are others - check the Joyetech website for vendors/partners and also check the 'copycat' listings. $17 each - get two.
https://www.cignot.com/product_p/egc-ubt-all.htm
