Toyota Prius 2008 battery upgrade

Hi, we have in the family an older Prius (2008) and I was thinking - is it possible/ have anyone done, an upgrade on the battery on the second generation Prius to extend the range it can travel on electric motor alone? Also this car has a limiter that allows it to travel on electric motor alone only up to 40km/h I believe..

I am thinking of raising this limit up to about 60km/h (would this not damage the motor for extended use?) and also adding extra battery so it can run on electric motor alone for longer distance. What would be the main problems with this idea? Probably the programming I am thinking, would any service in Europe be able to help me with this?

Thanks!

I used to be involved with the "plug in prius" modification scene, but it has been years since that! It is certainly possible and can have good results, but has gotten less popular since there are many more plug-in cars on the market these days.

The Gen 2 prius transmission can run completely electrically up to about 41-43mph at which point MG1 is spinning at its speed limit and it must spin the engine in order to get the RPM down on MG1. It is still possible to drive the car faster than that while burning no fuel in the engine. Some of the more recent plug-in outfits are claiming they can drive 100% electric up to 70mph, but I don't know the details of how they are interfacing with the stock hybrid and engine ECUs to allow that to happen.

Anyhow, there is a lot of great intro info about the prius tech systems: http://techno-fandom.org/~hobbit/#prius

And, like I said I am pretty out of the loop with plug-in prius systems these days but I have heard of some pretty nice stuff going on there, I think your research into those things would be as effective as mine!