Prius Battery Replacement (GenII) Like you've never seen - NEW Cylindrical Cells

ROFLMAO!!! The Ideal gas LAW has absolutely NOTHING WHAT-SO-EVER to do with airflow..... OMG! Time to educate yourself.

Hmm, the more you draw from a pack and the more you replenish has nothing to do with temperature? I thought you posted that current flow increases temperature - suddenly it does not?

Again, go educate yourself. Look at the OPs packaging and then that of a Gen2 HV pack and try to tell us that placing the OEM cells ACCROSS the direction of airflow, thereby blocking it, is better. Oh, since you are so keen on the speculation idea, where is your data that it is better.

BTW, if you took time to read the plainly worded reply of mine above, you could have understood that I clearly indicated that the BMS Toyota designed (due to the very infrequent fan use most experience) is THE primary differentiator. Oh, that also dispels your theories.

Again, educate yourself, comprehension should be goal #1. I posted that I understood how it would be possible for the pack to run cooler. Apparently you feel that tighter spacing and restricted airflow will transfer heat better, in the real world it does not.

IMA: Fan mounted UNDER the electronics package, SUCKS air across the HV pack with limited ducting. Obviously you know zip about how fans and airflow work, or you would have noticed these important differences.

I understand completely. Convection DEPENDS upon conduction, DUH.

Actually, go back to Physics 101 please. Conduction occurs between ANY two materials in contact. Believe it or not, air is a material.

Um, forced or not, convection occurs due to differences in the density between hot and cold air. This is why the earth has weather and radiators of old did not need fluid pumps or fans.

 

Now block that cool photo of airflow with 28 flat plates and tell us the flow mass-flow of the air is better and of course therefore the cooling of the plate type cells.

When you are confused by that, put a piece of cardboard in front of your radiator, so the air must flow around it. Then report back how much better the mas flow was and cooler the engine ran.

 

I thought it was established that the Cali experiment was recycling old modules and the rebuild was being done by a third party in partnership with Toyota CA. I may be wrong, but that's my recall.

 

Heat transfer improves when the hot air from the heat source is mixed with the cold air. What you want is turbulent airflow to break apart the surface hot air skin (which insulates) and mix it with the incoming cooler air. Streamlining by making the surfaces flat does not increase turbulence. This is why the airflow ventilating Toyota's battery is in a downward direction. The cold intake air moving down against the hot rising air off the battery modules boosts turbulence. That's one reason why computer CPUs have a fan AND a heatsink. That perfect flat metal surface on the CPU doesn't transfer heat too well.

And another thing that helps is by breaking apart one heat source into three. This should increase the mixing of hot and cold air.

And by increasing surface area. I have seen and studied many CPU heatsinks - the ones with the most fins dump the most heat.

The problem with water boiler systems is the steam bubbles that form on the bottom can combine into larger bubbles that are slower to rise out of a kettle. These large steam bubbles are the cause of boiler system malfunctions and inefficiencies because they insulate the kettle bottom and cause hot spots. A bleeding edge solution is to line the bottom of the kettle with hydrophobic material that encourages tiny steam bubbles to form and release - thus improving the mixing of hot and cold.

Pixel XL ?

 

Holy christ has this thread gone stupid.

 

This.

 

Now your are being rude again. Using a thermal camera after you have taken time to stop remove the seats and cover is a pretty poor thermal test.

 

Corrections:
1) Yesterday, I shopped for genuine Toyota packs and quickly found several dealers have online prices for $2070 or less. It is very easy to google this fact.
2) Used Prius cells are currently selling for $27, not $40. Max potential for months of extra effort of advertising, packing, ebay monitoring etc, is $750. Wise owners will save their old packs just in case this new experiment fails (just like the Enginer's experiment failed).
3) So the simple, more likely math choice remains even at $2050 for a genuine Toyota warranty vs $2000 for an untested, early stage experiment with giant questions about reliability and NO WARRANTY.

 

I provided you with the textbook definition of conduction. You can't redefine an entire engineering principle to make an invalid argument work.

I'm sorry you don't get it.

I absolutely read that, and it's primarily why I have so strong an opinion. If you believe that a FLIR is sufficient instrumentation, you've confirmed my assertions. You have not collected any meaningful temperature data on your cylindrical pack.

I am arguing because you are making MULTIPLE false claims of superiority. Many of which are completely unjustifiable on any grounds, and the others are based on extremely limited testing and a LOT of extrapolation based purely on whim.

Please look up the word "plenum". The Prius pack cooling works by pressurizing the upper plenum and allowing 29 uniform exit passages. The airflow through a Prius pack is amazingly uniform. I have personally tested this by pressurizing the lower plenum via the exit duct and allowing airflow to flow upwards. it will float a piece of paper anywhere you put it with the fan running at 9V. Put a full 12V into the fan, and the paper goes flying.

Your comment about a piece of cardboard and a radiator makes it clear you lack a fundamental understanding of the Prius cooling system.

Ultimately, time will tell. When packs are dropping off like flies in hotter regions of the country, hopefully, this will still be around as a lesson for 2k1Toaster.

 

Again, thermal data from the sensors is meaningless when you have changed pressure, velocity, surface area, flow characteristics and section thickness. Lab ovens give you nothing meaningful about the cooling system.

I really would like you to succeed if this is a viable option. Unfortunately, all you're providing is lots of hype without any substance.

 

Your tests are crap! Thermal tests without all the covers and seats (aka insulation and air sealing) are pointless.

 

A few questions.

1. How long is install time?
2. Is it really just take out the old battery, take out the old cells, put your new ones in, and put the battery back in the car? No balancing modules or anything like that?
3. If I have questions or am having trouble with installation would you be willing to talk through PM or something like that? I am an engineer and my dad works on hotrods in his spare time, so it's not like we're grandmas. Based on the cell-replacement tutorials I've seen on YouTube, it looks easy enough, but I would want that peace of mind that I won't be entirely on my own here.
4. How much of a discount are we looking at?

 

correct, i had to go back and read a few pages of that thread. it's too bad we don't have more info and history on these reman batteries and pilot program, haven't seen too many posts here.

 

Testing for real world heat loss happens to be MY area of professional expertise. I infrared cams are great, but heat loss/gain is best measured under stress loads with all insulation and air sealing in place. Your theoretical "superior" design needs to be tested DURING real-world driving. Removing seats and covers is not a real test. After the car has stopped is not a complete test. Asking $2000 for an untested automobile product and claiming is superior, is quite possibly criminal. Please be more careful (and polite).