Definitely doable.
After you do the swap and are done with your trip.
- - - - - - - -
I recommend testing the 'dead' pack for yourself.
Doing each one of the 20 sub-pack 6 cell sticks with one of the RC battery analyzers.
Batteries can fail for a lot of reasons ... some are non-treatable issues ... But , some of the the failure modes can be treated ... and can allow for more useful life to be extracted from the pack after treatment.
If you test the each of the 20 sticks in the pack you will be able to get an ideal of what type of issue there is ... and what might be involved in servicing / treating that issue.
The things I would recommend testing on each of the 20 sticks include:
- Discharge capacity ... Ah or Wh
- Internal Resistance ( separately for charging & discharging )
- Can be reasonably estimated from the change in voltage ( dV ) of a rested stick under a known current rate of charging or discharging.