I now own three K2's...
Long term review:
Of the cables I have had made everyone is the right size, but, are loose at the K2 port. Conversely, the OEM supplied cables are tighter...very strange.
I think I've got noise in the power on rare occasion from the above loose connection...from the internal battery kicking in and out to cover for the dropped power. That said, it appears to be associated with only one of the three batteries. I've taken to gaff taping the RA connector/power cable down on the unit and that appears to have fixed that issue.
Why three when one will run 2-3 days of a festival...running two stages...phone charger...running a laptop for backup at festival campsite. I'm looking for a nice 12v DC powered Desktop speaker setup for camp music...
What I miss is the security of connections, even the old Tekkeon Kycon DC Power Connector feels loads more secure. Strongly considering going V-Mount 14.4 v batteries with a DTap. Similar battery meter...voltage coming right off the battery cells (no noise from voltage step down an loss of efficiency associated with it). Some V-Mount Batteries have USB outputs too. Downside is more expensive when compared to K2 for same or less capacity and no 12v output, but, that is not an issue with my current recorder that takes up to 16v.