Dr. Prius App - Prius Gen1 beta testers wanted !

Hi Ken, most people can't understand the real-time graph and that's totally normal.

That's what the "full battery diagnostic page" and "life expectancy test page" for, you basically just need to follow the instruction and App will perform all the calculation in the background and tell you which block is getting weak, which block is not working properly and what's the remaining capacity of the battery.

just FYI you can also visit Toyota dealership to perform a life expectancy test, however they usually charge 350 USD minimum for that service. You can also buy Techstream from Toyota or from eBay(Pirate) and learn and try to figure things out but that will also cost you way over $8

 

The biggest challenging being the Prius battery ECU doesn't stop charging at 16V, it often over charge the NiMH battery module to 19v or higher depend on the "max charge/charge control" parameter at that moment, that's why you can see my prototype have this big resistor to help dissipated the extra energy from the over charge, another challenge being the cost as LTO battery is super durable but also pricey, solid state sounds like a perfect candidate but it will experience the same challenge ahead.

 

Thanks Mavi, I currently have 6 different LTO battery samples from 3 different manufactures, it's gonna be fun!

 

Yes, this project have been going on for more than 3 years now and lucky only one fire with the Lithium NMC battery at the early stage of the experiment, that lead me to the safer LiFePO4 and now the Lithium Titanate. I test different chemistry battery on my two Prius on daily basis hence creating this Dr. Prius App to help, glad it also helps other DIYer + repair shop and earn some seed money in the process.

 

I have tried Toshiba LTO, as a matter of fact I have couple boxes of them, however unfortunately their voltage curve is too flat (too stable) means the voltage stay the same most of the time and then just suddenly empty and drop to 0 v, it cause error code at the end.

I found another LTO factory in China with much linear voltage curve, however their cost is higher and they only accept large quantity, still trying to figure this whole thing out.

 

Hi there, sorry for the late respond, was on a business trip for the past few weeks.

Yup, if you are interested in the Toshiba cell I can sell them to you for a steal price, they are designed to last forever as long as you don't overcharge them, I am in Los Angeles, PM me.

Jack

 

nice seeing you and hope you likes the LTO cells, let us know what your applications are and how they hold up to their reputation !!

 

Thanks for sharing Todd, OBDLink LX is the best but a bit pricey, there are other more affordable alternative can be found on my comparison blog: Hybrid battery diagnostic and repair tool for Toyota and Lexus , my new favorite is the Carista OBD adapter. FYI.

 

Yup, that's correct, looks like you have the Prius Gen4 one or two Eco where Toyota cheap out on the amount of sensors they put into the battery to reduce the production cost, even myself was shocked/puzzled when I first seeing this weird number, and later found out Toyota has so much confidence with their latest NiMH battery technology/safety that they have decided to put 4 blades into one block, compare to the normal 2 blades into one block approach.

With that being said, Dr. Prius App is fully compensated for that so you don't need to worry. Yellow and Red means the voltage is outside the comfort zone of the battery chemistry but a short period of exposure is fine, this is non-lithium after all.

hope this helps.
Jack