Yes, removing the battery does require a complete tear down.
Even removing the HDD required this, because there is no easy access to the motherboard, or any other components like you see on some laptops. To access the HDD on this model, you have to remove all screws from the bottom, pry off two panels from above the keyboard, remove the keyboard, take out some more screws, then remove the rest of the casing around the keyboard. Once this is done, you have to remove the motherboard from the bottom plate ( more screws ) and then flip it over. It was a pain. And the battery removal trick had no impact.
There were no other connectors, and no other HDD bays either.
I didn't take note of what chipset was used on the motherboard, but I suppose I could find out and see if I can cobble something together with that chipset and the hdd with a different BIOS. Maybe use that mobo and chipset as a surrogate while troubleshooting.