Gruntled,
I'm using an A123 4600 2S2P
http://www.electrodynam.com/store/product270.html for my Rhino with the igniter. Works great! I've never experienced the problem that you've described.
Also, I tried moving the ground strap as Eric described and it did not ground. I'm not sure why it didn't ground, but I had to move the strap back to the igniter.