Proper Wiring for 2 - 5S packs into 1- 10S pack
Sample of 2 -5S packs into 1 - 10S pack with proper balancer identification
Wiring 2 - 5S packs into 1 - 10S pack can be done permanently or with connectors. This is an example of a hard wired assembly. A series connection has the black wire from one pack connected to the red wire from the 2nd pack. The remaining longer wires go to the pack's main connector that plugs into the speed controller. It does not matter which battery is on the left or right side, what matters is which leads go to the main power connector.
"A" side or "channel 1" has the negative lead going to your output connector. "B" side or "channel 2 has the positive lead going to the main power connector. - Always
Close up of completed pack. Note small balsa spacers for airflow between the packs
Another example. This setup has the "A" battery on top and the "B" battery below but the setup is correct since the "A" pack has the BLACK lead going to the power connector and the "B" pack has the RED lead going to the power connector.
(drawing courtesy of Marvin Marozas)
Summary:
Thunder Power "Group A" and CellPro "Channel 1" both use the pack with the black main power output lead
Thunder Power "Group B" and CellPro "Channel 2" both use the pack with the red main power output lead.