I'd be comfortable with the 2 Amp charger. I routinely hook my iStick TC40Ws (and my iStick 20s before that) to a 2.6 Amp charger and (according to my pass-through Ammeter) they only draw a bit under 1 Amp. The iSticks can evidently regulate their rate of charge from a heavy-duty charger just fine.https://www.amazon.com/gp/product/B00J3JSEG6/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 ($10)This is the one I use. Actually I use six of them on a six output, 2.6 Amp per output charger, so I have a bank of charging ports available with different charging cables on each. Being able to see what each device is drawing lets me be ready to "pull the plug" on any device that looks like misbehaving. (So far only one device - I forget what it was, but I tossed it immediately - has misbehaved. I'm not even sure it was vaping-related.)In fact, if your mod wants to draw 1.5 Amps and the charger can only deliver 1 Amp, it might be over-straining the charger (not good). Again, this is what the pass-through Ammeters are good for - telling you what is actually going on. Of course, it may well be that your iStick can get along on 1 Amp just fine and maybe it would be better for battery life to charge the battery at the slower rate.