Yihi used to be good.. slightly behind DNA IMHO... but, recently I bought the IPV8.. OMG, terrible... I donno how to explain. But, the power seems very weak, unlike previous IPV especially when we do TC... I tuned around the TCR setting. Same. At the end, gave up and sold off after three days of frustration. Frankly, I think my pico and pico dual much better than the IPV8 despite the facts that IPV8 looks so cool on surface 

so, the problems perhaps lies with the YiHi SX330-F8 chip on IPV8... 
But, sometimes we can't compares the SX Mini G with IPV8.. pricing wise, both are from different planet. So, the only thing I can conclude is .. don't buy YIHI's cheap stuff. 

SS316L dual coils, spaced single strand + Kendo cotton. Juice is Naked 100, which is particularly clean for something that's not unflavoured. 50w,  480-500f.

And yeah, seems that spaced coils DO help keep things running slightly longer. Also slightly bigger surface area and more even heating IMHO vs contact coils.

Myself my builds are all spaced, even the exotic wire ones. Props to andyng38 for suggesting spaced coils to me almost a year ago, even if I was kinda sorta sceptical myself back then. 

Haven't been running contact coils ever since lol.

You can file an appeal...but it'll probably be futile. Once nicotine-laced juices r in the pharma dept, they're as good as gone. Sorry for your loss

Since u r in sg, surf to https://sg.carousell.com/ , type in the search box a mod manufacturer's name (ijoy/wismec/smok etc). It may take several tries over a few days, but eventually a seller will pop up. Chat with the guy for e-juice supply. They have runners bringing the stuff in from indon and JB. Prices are high, and u will be checked out at meetups before any product is shown...very cloak n dagger.

1) It's called a Variable Wattage Mod so that you can vary the wattage to your needs / tastes. If you like 45, stick with 45. More power = more heat most of the time.

Recommended wattage is actually more like "this coil goes to about this high" (aka "max" wattage).

2) Like I said before, today's Efest batts (Metallics) are mostly just LG/Sony/Sammy rewraps anyway (with largely bogus max amp/cap claims). The key word here being "LG/Sony/Sammy rewraps", which means that for the most part, they should be fine up to 20A (as per Abam Mooch's tests anyway).

The only issue is that most of the time they're sold as "premium" batteries DUE to the bogus amp/cap claims and are thus inappropriately more expensive then Ori LG/Sony/Sammy batts. That's all.

Solotech, I'm not so sure but I think they're ALSO rewraps. They're not in my edition of Abam Mooch's charts though. Do check to confirm.

3) This part is much more complicated, but IINM that 17A is being drawn from both batts (20A+20A limit). Do read the manual to confirm though, as whatever is displayed on your screen is mod-specific.

Do read here if you're interested in the details though: https://goo.gl/poIE1Q

Finally, yeah, it sounds like you're doing just fine. Just remember to keep your batteries married (keep cells in matched pairs), to carry spares in the proper containers AND to charge them appropriately.

If your mod has balanced charging (again, read the manual - but AFAIK all newer Smok devices have BC built in, but please do re-confirm), it's fine to charge through USB. Otherwise, charge externally in married pairs ALWAYS (as this is WHY you "marry" batteries for multi-cell Mods in the first place).

So yeah. Keep safe and vape on!