Yes, that's correct. The 20C rating of the battery is its max discharge rate and that will double when you add another battery in parallel.
Example:
2200mAh battery x 20C = 44A current draw
Add another 2200mAh battery in series and you get this:
4400mAh battery x 20C = 88A current draw
Make sure both batteries have the same charge level when connecting them to avoid any damage to the batteries!
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