The Cellpro charges through the balancing taps up to 4 amps, beyond that it requires the main leads to be plugged in. In this case I was charging several things at once and didn't want to pull more than 4 amps from the power supply anyways so I wasn't using the main leads. Guess this is a good reason to use them anyways!

BTW, after this occurred I found a couple of old TP taps from another application, removed the wires and inserted the bare taps in the 4s socket so this won't happen again. My point here is to warn others.

Keith