I am using the Xennon blue tape from Speedtech and so far so good. It's quality is just as good as the famous Tamiya tape (does that say enough about how good it is?). The xennon stuff is wider to cover more battery but is a hair thinner than the tamiya tape. So far I have had no problems with it and a strip will last all day if you prepare it right. When you tape your batteries in, fold over a tiny amount at the ends to create "handles" to pull the tape with. I've used a single piece all day in practice on Monday and kept it for racing on Tuesday. The same piece of tape is still in my car and I'll more than likely use it Saturday
Good stuff and it matches my blue car perfectly...bling bling!