Sabimaru is an incredibly knowledgeable person, but a not so sociable one, being incredibly shy and often mumbling or speaking far too quietly for anyone to hear.

This requires him to depend on Isaac to do the talking for him, who is Sabimaru's AI who happens to have the same voice as him, bound to a tablet, talking in a sassy attitude and communicating what's on Sabimaru's mind loud and clear. So, when Isaac's out of battery, Sabimaru turns to panic very quickly.