It depends almost entirely on how heavily you vape, which is the honest answer. The SlimStick is a prefilled system with a modest battery to keep the size down, so a light user who takes a few draws an hour will comfortably get a day out of it. A moderate user will probably need a charge at lunch or an evening top-up. A heavy user will be looking at mid-afternoon. The genuine strength of the SlimStick is that it is so thin it fits anywhere - into a shirt pocket, a jeans coin pocket, easily forgotten until you need it - so the trade-off is that battery longevity sacrificed some capacity for portability. If you are a moderate to heavy user, honestly the XLIM Go Lite is a better fit because it lasts longer on the same form factor, and the XLIM Go is genuinely all-day if you want real staying power. That said, if you are genuinely light to moderate and the slim form factor is the whole point, a midday charge is not a huge imposition and the device does charge reasonably quickly on USB-C. The best way to judge is to ask yourself whether you would actually use it if the battery lasts exactly 4 hours versus 8 hours. If 4 hours would still be your daily device, then you have your answer right there.

I use mine as a backup device and the pocket size is the whole point. A lunchtime charge is genuinely fine with me because I am only using it when my main device is not with me.

I think moderate use is me, so a midday charge seems like a reasonable ask for something this slim. Good to know it is not a fault if the battery does not last forever on something this small.