Rog, I'd suspect the voltwatcher as well. If you have one back check it with a digital voltmenter on the pack at the same time as the VW. It may be that there's a fault in the VW or that it may be sucking too much current for the smaller pack so it's pulling down the voltage. If you've got a voltmeter in parallel that'll double check the reading. Also if you can setup the multimeter to current readings and check how much current the VW is pulling.

If you're after a cycler then there's a lot of options these days. I've recently bought two field chargers for quite cheap that do Nicds, Nimh, lead acid and Lipo's across a wide range of voltages and capacities. It also will discharge/cycle the packs and give you a time reading at the end of the run so you can figure out the MaH capacity with a bit of simple math. It fully takes the place of the previously excellent Digipace or similar.

The second one I got is a Hyperion EOS 5i. It was only $60 at our local trade show. So I'm guessing you can get them online for about the same money. The other one I got is the Triton Jr for a lot more money but it was Canada so we expect that. Still, it was good value for the money given they wide range of capability.