I just bought a 2003 Prius used from a local dealer, and the HV battery is worn out (according to the Toyota dealership that inspected it). Now the dealer wants 3400 for the new battery and installation, but I found cheaper battery online from a second generation Prius. My question is, will the second or third generation HV batteries fit in a Gen 1 prius?
The battery cells/packs will, but the Gen 1 uses a different number of packs (17?) and different control electronics and ECU, but people often swap out the bad Gen 1 cells with Gen 2 then charge them so they are balanced.
No, but the links at Failed traction (HV) battery, what to do? - Prius Wiki might help. The total pack voltage and # of cells are definitely different between Gen 1 and Gen 2. You can see that if you look at the ERGs at the bottom of https://techinfo.toyota.com/public/main/erg.html. But yes, people have been able to rebuild/repair Gen 1 packs using Gen 2 cells. Hope you didn't pay too much for that Gen 1 or can return it you don't want to spend the $ to fix it.
A site with some good images, Tim Jannello started the switch but had problems with a cracked cell in the replacement , possibly "overcharged due to lack of initialization of the ecu" , but repaired/replaced the positive bus bars and fixed his original battery. http://opensiuc.lib.siu.edu/cgi/viewcontent.cgi?article=1028&context=auto_pres
The NHW11 uses 38 modules in 19 pairs. The NHW20 uses 28 modules in 14 pairs. You can replace all NHW11 modules with NHW20 modules and IF you pay attention to charge and capacity, it will run cooler and a long time. You might contact ReInVolt in North Carolina. They sell fully rebuilt packs which I switched to in Nov. 2009. GOOD LUCK! Bob Wilson
