Since the holidays we have seen a few ZZ MTs returned to the RS where i work, so I have a growing parts collection, including batteries.
(This is just ZZ MTs mind you, I already have a ton of original ZZ/MS/Bit/Clone parts from back in the day.)
My "MH" crawler goes through even a double-charge pretty quickly as it's geared down and has an upgraded steering motor.
I really want to crawl some rocks with this thing, or at least attempt it, so I want it to run longer...I think.
My thought was to simply add a second complete battery pack, but connect them in parallel for twice the running time.
It also keeps things simple by allowing a non-modified charger to be used. (okay four charges, but still...
)