SonOfAnakin,
I've have recently come across the same issue. The problem is that the charge tank will only hold the battery contactor closed for a short period of time (less than an hour, I think) when it detects no current being delivered from the level 2 charger. At this point, the bike will go back to the "key off" position, and will not come back on, even when power is delivered from the level 2 charger. I believe one of the smart charger companies in the UK had the same issue with the MG ZS SUV, and their solution was to "trickle charge" the MG at approximately 6 Amps, thus keeping the MG awake until the night rate kicked in, and then switching to the full 32 Amps.
Unfortunately, this is not really viable with the Zero, as it would probably be well through the charge cycle before the lower night rate started. I have, however, been experimenting with another solution, and it is possible to use the on-board charger to "kick start" the level 2 charger, by the use of a charge lead which provides power to both the charge tank and the OBC simultaneously.
In this case, all you have to do is key on the bike, plug in the level 2 charge lead to both the charge tank and the OBC, and connect it to the charge point. The charge point will detect the presence of the bike, allowing it to schedule the smart charge. The bike can then be keyed off as normal. The charge tank will eventually open the battery contactor, and put the bike back "to sleep", however, when the smart charger starts the charging cycle, it will trigger the OBC, which will in turn activate the charge tank. With both chargers operating you will also be charging at over 7kW!
I believe it should also be possible to make up a special charging cable which won't require the bike to be keyed on initially, and which will only run the OBC for a few minutes (just long enough to kick start the charge tank), but so far, I haven't located the correct relay/contactor which would allow this to work...
Ulster Zero