Project Lithium customer review

And its conductive metal - I took an ohm meter to the pack. My guess is the nipples and ribs create a space between adjacent cells which allows convective airflow which is augmented by the forced air blower. The Panasonic Prismatic Pack is 94V0 - it says so on their datasheet. Of course NiMH packs do outgas a bit during operation which is what the rubber tubbing that goes to the nipples on the top is all about. That tube goes off to the exhaust vent. You can read about the chemistry venting at the battery university website, great resource.

 

I really have no prejudice against any innovation that comes along or from where. The question is legit as it raises a safety concern. There is no such thing as a chemical battery charge/discharge process that is not exothermic. That temperature delta will vary with the chemistry and is mitigated with design augmentation to evacuate the heat when it occurs. As noted Tesla has to do this with their three battery chemistries. In fact if you look at the new 4680 battery the design is heavily modified to move heat out of the cell as fast as possible. This will allow faster charge times. The pack, again, has a liquid cooling loop and the radiator fans operate during charge to move that heat away. So lithium does not have a pass on thermal management - not by a long shot.
The second aspect about the upgrade is there is no firmware change to the BMS module (battery management system) as far as I can tell. The BMS is fine tuned to monitor the temperature/charge[discharge] current curves to mitigate danger. This is why your Prius "runs" when the battery pack gets to full green on the display. Its adding a "dummy" load to the system. If you look at off the shelf BMS' they have specific tables to use with specific battery chemistry. So that is curious.

 

Thanks. I've used DrPrius - which is fine for battery SOC monitoring. I use Torque Plus - with the Prius PIDs downloaded - to be able to chart some interesting things. For example you can monitor your Catalytic degradation which is useful. When I line graph the temps of the inverter and the battery temp sensors (3) I can see a direct relation between the peaking of the temps. You have to go into a non-motor charging state to really see the worst case. For example if you take your foot off the gas and roll (in B) down a very steep long hill you will watch the charge cycle and the heat rise dramatically. Going up the same hill, obviously with gas, at a very slow speed (not normal driving unless you are in a traffic jam) with do the same. This prolonged sustained "stress" will peak the temperatures. And that is the fundamental question. How badly? Because regardless of how badly the system must work and it must protect itself with on demand cooling. For eample in Dr Prius you can force the fans to turn on at a lower temp. That's fine - but not stock obviously.

And FYI for those who have not heard. Here in California Prius' are prized for their mileage and longevity with low cost of maintenance. Taxi companies use them alot. I asked a cabbie, when I was taking a run to the airport, what sort of mileage they are seeing. He said 500,000 miles is doable with a single battery swap and the engine, being a true timing chain is bullet proof. Most original batteries lose the peak economy (46 to 52 MPG) by 320,000. Note that cabbies run all day with lots of charge discharge cycles keeping that battery young. I asked one of the battery swap companies what they are seeing and the answer was that the center NIMH cells tend to go out first because of heat stress. And the guy noted that deep cycling can bring a battery back to life for a couple more years. Note Toyota runs the batteries extremely conservatively between 20 and 80% charge to specifically reduce peak heat events.

 

Not sure what you’re talking about. I don’t make anything in China, never have. Never will. I’ve just dealt with them long enough to know how they work.
We need to bring manufacturing back to the USA.

 

I finished my NexCel install yesterday, I've only driven about 100 miles so far. I can tell the ICE does not kick in as much, and when at a stop the A/C runs on the battery much more. I'm going to get a kit for my other Prius when the stock battery goes out.
I'm very happy with the purchase. $2379.

 

How bad was your old battery? Did you need to replace it or just replaced it for other reasons? What was the trigger?

 

Does anyone have any first hand information on how long a Prius with the installed Project Lithium battery can sit unused so long as the 12v battery is charged? Seems like everyone that installs one uses the car daily. Does PL offer any guidance?

 

I know for fact a brand new Toyota NiMH battery can sit on the shelf for 2 years and still be installed in a car and it will fire right up.

I'd like to think a new Lithium could do the same or better.

 

The self discharge rate of the cells in a brand new battery should be very closely matched. So even though it might self discharge down to quite a low voltage in that time, it would still be balanced. That sort of symmetry will generally not be present in a battery with a lot of miles/age. If such a battery sits for several weeks some cells may have voltages substantially less than others, which can potentially result in damage to those cells when the car starts up. This is I think the reason why most hybrids have a warning in the users' manual stating that these cars should not sit unused for more than a couple of weeks.

As a matter of personal observation, in the two battery failures I had with an IMA pack on our old Honda Civic Hybrid both followed shortly after being parked for an extended period. The first one was when it was parked at the airport during a trip, and the other was when it was having transmission work. (The HCH I CVT transmission was a fragile POS.)

 

Why does your car show 0.0mpg? Does the lithium battery prevent accurate readings? Or did you just clear?

 

He is stationary, presumably, so he can safely take the photos. Notice that there are no energy lines on the Energy Monitor screen.

 

Hey how's the project lithium battery doing now? Researching it for when my $800 rebuild goes bad but so far so good according to Dr Prius (from Hybrid Geek).

Owner of 2004 Prius bought new looking forward to making the 29 year mark and then some .