So I was thinking that the ideal way to modify an existing Prius to be more EV like is to add extra junkyard Prius batteries, with quick disconnect on them. That way you could charge it, and put it in for use. Then when you want normal factory Hybrid use, you disconnect. That would help not to exceed the GVW (gross vehicle weight), as set by the manufacturer. Thus no worries about stopping power, or handling. Someone has thought of this before? Right? Also would want to try out the junkyard battery for testing for a day or two. Just to make sure that the junkyard battery has not already had the capacity reduced, due to sitting uncharged for days/weeks/months. Would like to return it if it is only a 60% normal, compared to new battery.
offroad1994, Welcome to PriusChat. There has been much discussion here of different ways to get more mileage out of the electric side of the Hybrid Synergy Drive (HSD). It is by no means a simple thing as the control algorythms are extremely complex and the built-in monitory systems have very narrow safety margins. Use the search function with PHEV as the search term. Settle back and be prepared for an education... there goes the three day weekend!
Just thought some smart engineer had already invented this DO-IT-YOURSELF modification of the computer, and posted it in a FAQ somewhere. Yes, most likely I would need to search this out and filter through too much false information, over a few days. Yes, the algorythms are complex for monitoring and working the battery physics; but nothing impossible for the folks that reprogram computer chips on cars across the nation, for performance improvements (that void warrentys all the time). I think CALCARS.COM did this, but their focus seems to be on a LITHIUM-ION battery solution, and fulltime PHEV. I like modification to PART-TIME PHEV with used junkyard Prius batteries.
Here is a great PHEV discussion http://priuschat.com/forums/prius-modifications/26092-my-official-prius-plus-mods-thread.html