Ways to protect MMM when used with subpar batts

[BrianG]

The long and short of it:

Extra caps will help reduce the ripple current. However, more capacitance creates a bigger hookup spark, which eats away at the connectors each time it arcs.

Extra TVS devices are to clamp the braking voltages to a safe value.

So, both of these will help when using subpar batteries. But IMO, it's better to use those cells in a smaller/lighter/less demanding setup instead.