Originally Posted by
hydrocarbon
Trying to add an extra battery can cause a lot of problems if it isn't done right. I normally just carry an second battery when I need extra range and swap out when the first one dies. Less weight for trips where you don't need two, and fewer failure points under all circumstances.
One of my bikes does have the factory-fitted dual battery setup, but it isn't a big deal compared to just keeping it simple and swapping out two batteries with a standard single mount.
Sounds good, but ....to find a (the right!) frame bag to carry that extra battery is a bit of a challenge.