dr prius lithuim modules problems

back to winter again and having problems again , after about 18000 miles and perfect performance with no problems on the new gen 2 li battery packs . from using scanning tools streaming live data while i drive i have learned a lot about why these packs are failing , and it appears not to be the fault of the manufacture of the packs themselves . it appears to be limitations of the chemistry of the li cells changing function with low and high temperature being severely different from that of the metal hydride batteries they replace and how the prius gen 2 computer handles it and does its diagnostic tests , which can prove seriously dangerous as it slams the electric motor into heavy regen then into heavy power assist essentially stomping on the brake then the accelerator back and forth for several minutes regardless if you are going around corners or maneuvering on ice etc. all without warning or requiring permission , it just starts doing it . that stupidity is on the toyota programmers and management. this of course starts happening at about freezing temperatures the li packs are designated by the prius computer as only being able to accept a charge or discharge at about 14kw even though the pack has close to normal voltages , ( i have seen charge and discharge rates at 60kw during normal operation ) , thus it surmises the pack cells are going bad and starts the test charge and discharge cycles to evaluate the extent of damage and if it needs to further restrict the packs use and turn on the red triangle of death and trouble codes. if the battery pack warms up enough it may decide the pack is still ok to use for now , if not , you get the codes. aside from the dangers of the prius oscillating slamming brakes and acceleration in icy conditions possibly while on curves or in problematic circumstances the rapid cycles of charge and discharge while the li cells are cold may damage the cells and thus later in summer when it gets hot , especially if your car was sitting out in the sun all day while you were at work and may get over 100 degrees ,and you try to drive home and end up going down a long steep hill overcharging an already damaged li battery pack it will then further be degraded to the point of actual cell failure ,
in summary the prius computer needs to re programmed also for various other issues , ( i hate the traction control , it causes problems in wet weather ,and ice/ snow and on gravel and mud .) and the battery pack and controller needs to be tailored to mesh well with the prius programming and what it expects the battery data to be in any given situation if you for example put another pack in parallel you would in theory double the capacity and safe charge and discharge rate at any given temperature which would allow normal operation in more extreme temperatures but may not be the best solution especially considering cost and how much more temperature range that would give you .the probably most practical path is to add a 12v hair dryer ( or resistor heat pads between or in the modules ) into the battery cooling system with diffusers and sensors and a programmable microcontroller to coordinate it all to keep the battery pack within acceptable operating temperatures for the li chemistry and accept in winter you would have to wait a few minutes for it to warm the pack before turning on the car. summer is a bigger problem , possibly running multiple hoses from air conditioner to battery cooling system might work to cool the pack after car sitting in sun and when outside air temps over 100 degrees , but that may be a lot of work and expense and you would have to wait for it to cool before yo could drive. if the modules had aluminum around the cells and part of the case the time to heat and cool would be less and a 12v mini fridge could be rigged to cool it in summer necessitating less modding of the prius itself . but increased 12v use means a bigger 12v battery and charger. probably a modest increase in pack capacity with some of the other toned down optimized options may work well enough for most without too much cost or labor making it possibly doable and cost effective but that is a whole lot of a mess of things to figure out and test to be able to push out a reliable plug and play product to sell to consumers. thus the last i heard jack of dr. prius is exploring sodium batteries which are cheaper and their chemistry is better in extreme temperatures but the pack will be bulkier and weigh more then the li cells. i wish him luck and hope he gets it figured out soon .

 

thank you rjparker for the info on turning off traction control , i have tried to turn it off though the dr.prius app several times and it either turned back on later or it seems to have just turned it down a notch or two.
from the some of the comments some people seem to react off first impressions or preconceptions instead of thuroughly reading the posts and dispassionately evaluating it considering the the various possibilities of what someone is trying to convey etc. as some have completely misconstrued what i posted and one essentially implied i am a liar . ridiculous .
i say its toyotas fault for the stupidity of not making its test or hv battery reconditioning cycles of regen/braking and discharge/acceleration , only happen on direct authorization by the driver or at least after adequate warning and time for the driver to be in a good situation , prepared for it , not as happened to me twice , going around a corner in the rain and Changning lanes in the rain where an off ramp is right after an on ramp where cars are constantly criss crossing each others path and many accidents normally occur and more warning signs keep getting added because of that fact. i did not blame toyota for lithium ion aftermarket problems.
i also was merely saying i did not blame the manufacturer of the lithium ion pouch cells or nexcell or jack or dr.prius for bad or defective manufacture of the physical products of the battery components themselves, Because the cells and the modules have worked perfectly well when they are within a mild temperature range and live up to the performance claims . the 2nd generation of the li modules seems to have solved prior overcharging problems to better protect the cells. therefore performance and quality of the components are good and not the problem. with the little tinkering and experience i have so far it seems to me there was not enough understanding and experimentation with how the prius programming manages the hv battery and how that would affect battery performance in freezing and hot temperatures and how the prius computer would deal with it and in turn what the computer would do affects battery cells. if you live in a relatively mild climate and flat driving conditions you would never see a problem and not expect to see one by using li cells by looking at data sheets of performance claims from cell manufacturers etc. and since toyota does not share programming code and details of what the prius battery management computer does exactly, it would be hard to be expected to know in advance how the programming would affect performance or cell health of li cells. however this is where experience tells you to play devils advocate and rigorously test all relevant extremes of variables involved that prospective customers would reasonably experience, so as to know for a fact the end results of operation in all the combination of reasonable circumstances. thus having the relevant data on hand to be able to competently decide if it is worth using li cells . this would also involve testing fixes for problems discovered during these real world tests, such as a way to heat the cells in cold weather and cool them in summer when your car has been baking in the parking lot all day. then of course testing those fixes. then designing efficient manufactured product that is economical and plug and play as possible. however to do all the real world testing and refining of all that is expensive and time consuming which would mean people in mild climates and driving conditions that will not have problems would not see these li cells for several additional years and at greater expense. so basically we went in on a beta product and are the real testers and the product has and hopefully will evolve to cover more extreme conditions that some of us experience.
as to the comment about the bus bars , they are definitely not the problem , i have a fair amount of electrical experience and refurbished the original hydride pack and its components and got a second one and refurbished it and bought replacement hydride modules and installed them in place of bad ones . so when the pack in the prius became unusable due to bad modules i swapped in the ready to go back up then swapped out bad modules in the on that failed. this worked quite well but was an extreme pain in the but as i had to swap modules out every 3 months because i did not just get all new cells to begin with, went the cheap rout with good shape used cells to replace the packs original ones dying of at the end of their life span, i should have at least just replaced all the original cells with the good refurb ones. so. at the time i was trying to decide between all new cells and good refurbs i saw the initial nexcell replacements and went in on it. now i am considering new hydrides or refurb hydrides , if i cannot hillbilly rig a heater for the pack.
the problem started when freezing temps hit long enough to drop pack temps in the core of the pouches and because i was monitoring live data i saw the computer throw trouble codes noting pack possibly bad and it was pending decision of triangle of death on an evaluation period ( during which the pack was restricted to 14kw charge and discharge and performance changed ) , then it did the test/reconditioning attempt , then declared the pack bad and red triangle of death appeared. then i used the obd2 tool to clear the codes and history . which made it run normally on the 2nd half hour of my drive home without problems. i also noted the battery temps increased , possibly enough to restore performance. and most importantly i noticed the charge/discharge test/reconditioning allowed the hv battery to charge to 100% and probably well past as i was monitoring live charge data , volts and amps going in as well as the displayed estimated state of charge.

 

in response to rjparkers last post , i agree totally . however i was explaining i sympathize with the entrepreneur's situation in trying to start a business on a helpful and worthwhile product that will help a lot of people with less than ideal financial backing and logistics and everything necessary to really do it right in the first gen of the product ,and thus having to make less than ideal development decisions.

 

in response to chapmanf's latest post the first video was watchable the two below were just pictures, but i think i know what you are getting at , however i have a 1st gen honda civic hybrid without traction control and an f450 4x4 diesel dually and i skid steer and a kawasaki mule utv and a quad and drove various other vehicles and i rarely spin the tires but most of the times in the prius usually in the rain ,the traction control is a detriment , it would be much better with an off button and you should be able to adjust the settings so it doesnt cut and then pour power back on so suddenly and give you a power bar representation of where the slipping point is occurring . in winter i run studded deep lug snow tires and carry chains in both my daily drivers . i do not like spinning tires especially with studs in snow tires that get destroyed fast, and then i have to pull them off and pull studs and put new ones in if the pockets are not destroyed. however there are some situations on wet gravel and mud going up the rear road to park the cars to clear the driveway i cannot get the prius up the hill but the honda with its 1st gen slippy cvt does using momentum and at the end spinning tires . the prius cuts out and causes premature slipping and losing momentum. and there have been many other instances where the traction control has proved less than helpful.