Featured Dr. Prius Packs Less Than A Year Away?

Here's pack #1 and #2 of the final pre-production test batch of Dr. Prius' aka: @jacktheripper's lithium packs for Prius.

It took 1/2 dozen years to get the right lithium chemistry and packet size to get to this point. And though the module cases were 3D printed, which took an exhausting amount of time per module, the weaknesses of 3D printing accuracy won't be an issue in the production version which will be a much more precise and quick to make injection molded plastic.

Above are the two initial test vehicles for these packs. On the left is a Prius modified for fastest lap times at the race track and it belongs to Rice Prius and on the right is my tired old 1/4 million mile Prius that's never needed any work other than basic engine and battery maintenance and is still all original parts in every possible way.

Our job is to torture these packs to death and hopefully they don't die and the design has no flaws so the investment in a full production order will be a viable investment that will keep older Prius on the road for decades to come. Once the decision is made to place the order roughly 6 months later you will be able to buy and put these modules in your own car and the price will be competitive with other existing options.

Initial impressions from Rice Prius and I is that we got triple the amount of miles in EV mode. Gen2 in US models wired out the EV mode, but it's fairly easy to wire it back in. I used to get less than a mile in EV mode before my charge level dropped down to 2 bars with even the best NiMH packs I've had. That made EV mode worthless because it made the engine waste lots of gas working hard to recharge the pack.

But when I tried it with this lithium pack I went triple that distance and didn't go below 4 bars of remaining charge and a few miles later pack was back up to green bars, and that was mostly with the heater on because it was cold out that night.

Because these packs don't modify the ECU it has to follow the NiMH power curve, so no huge boost in power at low speeds, but when you floor the gas pedal at 40mph there's much, much more available power compared to a regular Prius.

Also on long hard accelerations to freeway speed there's a noticeable draining out and gradual decline of power in NiMH packs that this pack doesn't have.

Rice Prius in a first reaction reply to Dr. Prius said: "I just got it installed, haven't tested it out yet but I'm already seeing much faster charging! I have a feeling that's going to translate into better MPG!"

@jacktheripper replied to say that the charge rates for this lithium type is at near 97% efficiency, compared to NiMH that only takes 70% of the charge with 30% lost to heat.

And if you live on the west coast and want to swap packs with me so you can help with torture testing get in touch with me.

And follow this thread as it develops and if you have questions or ideas about how to torture these packs in ways to ensure they have no design flaws please let us know?

in the meantime here's the spreadsheet where we'll be tracking module health:

 

One research question my buddy Joe, who's taken a bunch of classes and is investing heavily in lithium car battery maintenance and repair came up with is:

Are there any possible ways a lithium module can fail in a way that can not be detected by a Prius NiMH Battery Management System (BMS)? And if there was a way how could we create a situation like that to test it?

 

Production of packs will take 6 months and latest update is he's going to make the phone call to start production soon as winter testing is complete. Retail price likely just over $2K and hopefully price will go down as production ramps up and investment shows signs of success/pays for initial costs involved.

 

@jacktheripper is still kicking around price ideas.

I'm sure if you and others share your thoughts on here of what you think the best price should be he will take it into consideration. I don't get the impression that cost of production forces him into having to charge in $2200 range but there's more to a sound business plan than just how cheap you can sell it for, such as how price can be a way to limit demand so it doesn't exceed production rate, or vice versa.

I've been meaning to reply to his request for thoughts on pricing and haven't gotten around to it so I'll just do it right now:

My recommendation would be setting retail price at $2200, but only sell it at that price when supply is extremely limited and demand is extremely high. In general I'd align price breaks with shipments coming in and be willing to sell as low as $1600 if supply ever starts significantly outpacing demand.

What would you suggest for pricing?

 

Originally was planning to swap packs and test it in different types of use cases but Dr. Prius said he'd rather not add too many variables to the testing process, so for now I can't do that.

But I do rebuild regular NiMH packs periodically and am occasionally looking for a car to test a pack for a week or so to make sure it's without issue.

 

These days their isn't much difficulty in self distribution... Or at least at first when you're selling packs by the hundreds and then eventually up into the thousands. The distribution you're referring to is more for once you get up into tens or even hundreds of thousands of pack sold and I'm not thinking it's going to get to that level. I mean if you were selling a beverage, than a distributor like Coca-cola or Pepsi can expand your market reach a hundred-fold. Not so much with expensive hybrid car parts.

 

Dorman also is an IPO on Wall Street with $3.2 BIllion dollar market capitalization number: Dorman Products Market Cap | DORM

Dr. Prius is a start up app maker who has made only 1 app and has spent past 1/2 dozen years re-investing all existing revenue into marketing & research for a Lithium pack that runs in Prius and best case scenario won't sell it's first battery pack until Q4 of 2021.

Clearly there's a little bit of difference between the two...