Dr Prius Battery Life Expectancy Test

So I finally got my got my OBD bluetooth adapter in the mail.

This adapter works well (it's from the Dr. Prius recommended adapters page): https://www.aliexpress.com/item/32876810879.html?spm=a2g0o.order_list.0.0.57f41802KMyWsp

I paid for Dr. Prius basic edition ($13) and did a Life Expectancy test for my and my parent's Gen 3 Prii.

The results were:
2013 with 49k miles - 70.88 %
2011 with 86k miles - 68.85 %

By the way, Dr Prius recommends force charging the battery by holding the brake and accellerator down together for a minute. It basically won't start the test until the battery is greater than 70% SOC. However it's actually much easier to force charge the battery by coasting down a long hill. I drove up to the top of a nearby hill that's probably 200 - 300 m in elevation. Just by regen braking down it the battery quickly charged from 60 to 80%.

However I don't really know how to interpret this life expectancy test. My battery is basically 10 years old since date of manufacture. Dr. Prius is telling me I have used up half of the capacity (since replacement is necessary if you test < 40%). Has anyone gotten a similar test and how many years of life did you get after that point?

 

Yeah it does sound like it was an accurate number based on your test and a few other forum posts I've read.

My Prius did a lot of it's miles in the high Rockies. So it probably has been forced charged to quite a high level based on what I saw on coasting down even a small local hill. Then for a while during the pandemic all I did was start it and let it idle for a few hours once a week. Probably for 1-2 years it barely moved. So it's had some atypical usage.

Do you think it's worth doing? My issue is that the Prolong system is basically 2/3 the cost of a few year old battery from a wrecked car. I'm thining I'd rather just pay a few hundred more and get some much newer modules.

 

I'm glad it's working for you! My issue is that it's pretty spendy for something that doesn't have a lot of data to back it up. I've heard a few anecdotes from people that started using it at 10 years and are now at 16 or 17 years and battery still going. But these batteries already last 15 +- 2 years without anything special.

I can see that if your pack is throwing codes and you recondition, maybe swap a module or two, it'll buy you a couple more years. But will deep cycling the batteries really add longevity to a battery that already seems to last forever considering it's chemistry? Whenever you look up NiMH the expected lifespan is 3-5 years.. but somehow these Toyota packs last 15..

 

I guess I should search for more anecdotes about it. It doesn't help that there are so few reviews on the Prolong site itself.

My skepticism has been increased due to all the negative reports about Greenbean and other 'reconditioned batteries'. These places basically seem like a Ponzi scheme. You pay $1600 for a lifetime warranty and give them your battery in exchange for someone else's pack that has probably been cycled on a Prolong system. It usually dies, possibly within months or maybe you get a year or two. Either way the company is betting that eventually you sell the car or it gets junked and they stop having to provide you with warranty cores. Their only cost is that of the installation and time to recondition the packs they get for free. People seem to get awful mpg for the rest of the vehicle's life so it's basically just sort of managing to trick the ECU to continue driving on a barely functioning pack.