2004 Prius Dead Hybrid Battery

Hi folks! I've just started lurking around here. Bought a 2004 Prius back in 2019 and left it with my dad at the end of the year as I'm living internationally. At some point in 2020 it stopped working. I don't remember the details of the story, but basically he tested the voltages on the hybrid cells, found one or two that were lower, tried replacing those with some I got on eBay, but if the car recovered, it was only for a brief while. I am visiting home and want to revive it, but it was left untended for a year, and the first thing I found was that both batteries were completely dead. I got a new 12V, and ordered a 28 pack of refurbished and conditioned cells that should arrive in a few days. I'm going to install the cells, and if I'm really lucky, she'll start right up. But if I'm not so lucky, I'm thinking I'll want to be able to read all the proprietary Toyota codes. I've been looking around here, and getting a rough sense of how these knockoff techstream interfaces work. I went ahead and ordered a bluetooth OBD2 adapter so I could try Dr. Prius and maybe this Torque app to get useful battery information, and I'd like to get a decent techstream setup, but so far I haven't found anyone talking about specific recommendations. I see a few $40-ish Chinese options on eBay right now. Is there anyone with recent experience who can recommend a model that they know works?

 

Thanks bisco, exactly what I needed! Would be awesome to have more active members grabbing current models of these things, so I could just follow in some fella's footsteps, but that discussion still helps to build some confidence.