Here is my Kanthal wire coil hot air vape tool. This is about 5.3V 2.5A run through some kanthal wire. I chose to hack apart an old broken battery-powered soldering iron and use the infrastructure as a stand-in for most battery packs you find from radioshack, as they cannot handle the high current that NiMH batteries can put out. I have found it works very well on finely-ground bud, like what you would put in an MFLB. Smaller one for mobile: