Prius Gen2 battery replacement and conversion


10 W
Nov 24, 2020
I have a 2008 gen 2 Prius with an original NiMH battery.

The battery is aging and milage is not what it used to be. Has anyone had experience replacing these batteries with lithium cells, or perhaps running a lithium battery in parallel with the existing battery?

I'm also looking at options to convert to a plug in hybrid.

I've done some research, there are a few off the shelf solutions, but these seem to be put of stock or don't ship to Australia.

Has anyone done a diy replacement for the prius battery? Keen to understand how difficult it would be, any information is appreciated.
That post is shows replacement of OEM battery with another NIMH.

Has anyone replaced with a larger Lithium battery with its own BMS, and made it a plug in hybrid? Im wondering if this can be done, or if the car will reject a different battery and BMS.

In other words, does the prius battery management happen within the cars computer, or is the bms mounted on the battery itself? Can I just build a 200V lithium battery with BMS and plug in via two wires, or is it far more complex?
The BMS communicates with the car so you need it. I've seen some people hack the inverter to drive the electric motors from any battery, you do lose original functionality though.

Look up Prius inverter hacking on Google, you'll find quite a few forums with tons of information.
Whooo it's been a while since I've been around these parts but just noticed your question and thought I might suggest next Gen. They make an odd the shelf drop in replacement lithium iron phosphate replacement for $2300. It's the only replacement I would consider really. The development this guy has done is probably worth the cost of admission. Many in service and reliable.
Thanks for your post. I'm assuming you mean Nex Power ( "Next Gen" lithium is also a company but seems to only offer PV and home power batteries?

Nex Power do offer prius replacement batteries, but the price I see is $3221 (USD), and shipping to Australia is probably epic. Also, the product has been listed as "Sold Out" for over a year now. Id be interested to hear if anyone has bought from there recently.

Prius Gen2, Gen3, CT200h Lithium upgrade battery pack - 14 blocks