Bat-Pak
I have a bat-pak on my CT70HK0. With the key in the first ignition position, it will operate the brake light and the horn when the revs are up. In the second position (headlight), it only operates the headlight. All said and done, it works fine for just running around.
Instead of splicing the device into my wiring harness, I cut the connector off of the old battery and spliced that onto the bat-pak and plugged it in the harness. That way, if I want to use a battery again, I'm all set.