dr prius lithuim modules problems

in response to priuscamper's post:
i do not have a lot of specific knowledge of the prius drive train as i never had to replace and rebuild parts of it like i have had to with that damn 1st gen honda civic hybrid, but i cannot see how slipping would cause the electric motor to output more torque and damage the dampener as you say .other hybrids don't have traction control and don't self destruct when you spin the wheels. however it does seem plausible to cut power to prevent getting rpms too high and damaging components and tires that way but even then i think it is self limiting unless your wheels are off the ground and have absolutely no friction resistance and a simpler rpm limiter would solve that. what am i missing?

 

thank you chapmanf and rjparker for the useful information i will be studying up soon one way or another as even though my gen2 prius is in good shape except a deer head butted the side as i was going to work at 4am while driving on a rural road. it has about 250000 miles on it and eats some oil and it is only a matter of time until something critical wears out or breaks.
on a side note it got down below freezing the last few days and into the low twenties today a and my back up car , the 1st gen honda civic hybrid was throwing battery trouble codes at me , the battery pack was replaced by the dealership where the previous owner had it serviced the several years he owned it ,and the paperwork checks out , new cells of oem hydrides, about 60000 miles in 4 to 5 years. fairly mew , only 1/4 of their life span , and they do not like the cold either. it runs fine , just reduced power or on engine only until the battery pack warms up , but it has never tried to do charge / discharge cycles that brake and accelerate the car like the prius, of course that may happen later on as the pack ages or if the cells don't warm up fast enough. also the honda only has about a 15 or 17 hp electric assist motor the prius i believe has 50 or 60 hp. so if the honda was doing it i would be much less noticeable.
also another side note and comparison to the honda about braking drivetrain components , before i knew anything about the honda hybrids particular problems the cvt started slipping at high torque and rpms and had signature "judder" on take off and i actually tried a "burnishing the clutch" procedure that dealerships performed at the official recommendation of honda. which was their attempt to ( push off total failure till after the 80 000 mile warranty expired ) avoid replacing a cvt and drive train components that were designed for the honda insight not the heavier civic and so were over torqued in normal operation and wore out and broke components way faster than normal . the procedure consisted of jacking up the front wheels off the ground and goosing it up to about 35mph then slamming the brake ,and doing this a few times , and apparently this worked for a few thousand miles or so until it would start slipping again and then they would do the procedure again , then after the warranty expired honda told them to buy a new transmission. metal powder and flakes were a common occurrence in the cvt fluid. honda and the dealers had been misrepresenting the problem as a clutch slipping problem and all sorts of other problems , but iT became obvious when i tore my original cvt apart to rebuild it , that the steel belt spline segments were wearing down and slipping on the steel angled pulley halves and that the "burnishing the clutch " procedure was to cause a jolting severe friction to cause the belt segments to bite into the angled pulley halves in the low end range (where take off torque causes most of the slipping) and rough it up to increase friction for later normal operation. the 2nd gen cvt beefed up all the weak parts and added 20% more lower pulley range to solve the problems. i usually drive the honda in really bad conditions because it is more reliable in some ways and does not have the traction control problems and has less side wind drag and lower center of gravity and handles better ,and if it wrecks i have more steel around me and i don't have to deal with it's problems anymore . i got my use out of it , i only paid about $3000 for it and $ 700 for 2 parts cars. after that i think i probably would get another prius gen2 to replace it. better gas mileage and power and hauling room , higher ground clearance, etc ..

 

i just got home at 3 pm and it is still below freezing and amazon dropped of my new not so cheappo elm obd2 dongle thats works with the doctor prius app and played with it some and it started off with the prius battery pack restricted to about 14 hp charge and discharge maximum restrictions by the prius computer and all three battery temp sensors at 31 degrees f. because the prius had been sitting outside overnight . i cranked the heat up full fan and temp ,recycle air vented mid vents, to help warm the pack up as fast as possible, since the prius was not running under load but only idling enough to charge the pack at a max of 12 amps it did not get very hot . i started off into its charge and discharge cycles max 12 amp and avg 8amp charge and max 10amp and avg 6amp discharge. i let it do this for about ten minutes recording on the prius app and periodically taking screen shots. as the pack temperature rose the computer raised the max resrictions on charge and discharge to about 17hp at the end at about 40 degrees f.

 

tried to upload screenshots of the excell output of the dr prius app but it got fouled up , will have to figure it out later

 

prius ran fine in mid to high twenties temps but at reduced power on the way to work , a little under an hour drive got trouble codes towards the end . on the way back home battery temps got into the 90's when cabin temp was 70 , and charged to 100% and past according to the computer, and ended up pending a replace battery pack code.

 

i response to black_jmyntrn 's post
thank you for the information , i have several different kinds the wifi ones usually only work with proprietary software ,the blue tooth ones work with torque and dr.prius , i bought a panglong which claims to work with dr.prius but it kept cutting out and having communication errors so i am returning it . i bought a veepeek as well and so far it works pretty good for a generic semi cheapie . each one and software i have all have some trade of or another , some of the software has options others do not and some are a pain to customize to display what you want etc , so i use various ones for different things or situations,

 

speaking of wiring harness issues the slip control loosing coms with steering wheel angle sensor and other s completely stopped after i wiggled all its harness connectors .
when cold and heat cycles happen such as below freezing when i start the car in the morning then blasting the defroster for an hour on the way to work bringing everything up to 70 , then refreezing in the parking lot at work and then heating on the way home then freezing in the driveway over night , the plastic and metal contract and expand at different rates and thins move as well a condensation forms and corrodes stuff. which definitely affects electrical connections. when i was swapping out the two battery packs back and forth subbing in refurb modules i replaced the busbars in one with new nickel coated ones cleaned contacts , new nuts , and solderer flux cleaned wires and crimped connections ect the other one i wire brushed the copper bus bars and wire lugs clean and reused them, i checked connection pins and cleaned them later on and on one packs bus bars and contacts i applied an electrically conductive grease specifically designed to improve conduction and prevent corrosion in contacts . in the year and a half doing that i did not notice any additional degradation or corrosion , and performance and voltages etc did not change since i did all that . one pack was fairly pristine to begin with ( other than corrosion on the bus bars) the other had issues and that one if i had let it get much worse would have ended up causing problems.
i know from experience , electrical contacts and wires can be an intermittent or constant source of problems from working on sailboats and yachts decades ago , wires can crack and contacts corrode and things move with vibrations etc . that is one of the reasons why i am hesitant to lay blame on the manufacturer of the li cells , many things could be going on . however there are a lot of recurring data that is consistent with the cells not performing well with the cold , and the pack not meshing well with the prius programming and then the prius causing damage to the cells as a result of these compatibility issues . it is hard to get much more conclusive than that as i only have the data the prius computer spits out and how the car performs to go by , so far, i do not know the specifics of the li cells electric or electronic controller or protections etc. nor any of the programming of the prius . i will probably get some info about the cells when i finally pull the current pack with the li cells/module out ,probably to replace one that looks like it is possibly going bad , it seems its resistance and voltage fluctuations are moving out of step from the rest of the pack , it may be very slight now and may not develop into a bad module , but it might.
the prius was running semi normal after work except it was always trying to chare the battery to a higher level than before repeatedly going past 100% , then after i stopped for gas and shut it off and turned it back on it started behaving more normal yet. i want to not mess with the pack until this summer unless it fails before then , i want to see if it goes back to normal when the weather improves etc. and gather data until then .

 

on the way home it started in with its charge and discharge cycles , i used the dr. prius app for the first 60 % of the trip







then after a stop at the store used the x tool dongle and app




i also while parked at the store switched between the two
there appears to be many things going on at once and or one cascading into another . there are discrepancies , sometimes quite large 50 % or more in state of charge between what is graphically represented on the prius dash display of battery charge ( 8 horizontal bars i think ) and what the prius computer reports as state of charge ,granted there is a rounding up issue with only 8 bars to represent 0 to 100 , and of course the prius app i cant remember if it asked me if i was using the lithium replacement cells or not , i think it did , may be taking into account the lithium's chemistry and performance and different cells capacity etc and be reporting it's refigured estimation of pack, actual state of charge . and the prius computer i believe graphically is only displaying the range of the packs capacity it will allow to be used so as to never fully charge or discharge the pack , which would damage it i do not know if the reported obd2 % is raw capacity or this restricted down capacity . also it appears the prius in the morning when it is freezing out reduces allowable charge and discharge power but runs more or less normal with less performance then some time after i start driving home it decides that there is a problem with the pack then starts doing the charge and discharge cycles and it seems the pack cant hold a charge or the capacity is restricted to a quarter or less of the normal pack capacity , and then it just keeps trying to charge the pack all the time even when almost flooring it going up a steep hill . then the prius computer reporting of state of charge and the dash bars graphically representing it , jumps around , out of sink with each other (the graphical may just be lagging several seconds ) state of charge say change from 50% to 90% or 100% to 40%. , or be at 100% and continue to charge quite a bit . it seems like it may be part of some sort of test to figure out what the actual available capacity of the pack is , but it is getting conflicting data it cannot reconcile, and usually around this time i clear the trouble codes and history but unless i use my professional obd2 tool i cannot get the subcodes or more specific trouble codes and wipe all its history data it seems because some times it will not return to normal operation until i stop and turn the car off . then on the rest of the trip home it runs fine , just seems to allow itself to charge the pack a little higher than normal .
i need to research all i can on the battey management specifics of the prius computer and performance profile of the oem hydrides , to maybe figure out what is setting off the computer. it's going to turn into a lot of work to figure this out probably.

 

in response to black_jmyntrn post about making an all wheel drive prius , sounds cool . i once entertained the idea of getting 2 prius with rear end damage or complementary damage so they would be really cheap and take the front drive train out of one and put it in the back end of the better one so you could also steer the rear wheels as well as having double the power and and independent drive system providing redundancy , and you could crab walk it ! i figured out how to solve a lot of the control problems , but some things would require quite a few trade offs such as a lot of extra weight killing fuel economy and decreasing range , greatly reducing cargo room and having to create a firewall and extra reinforcing and fitting all the extra control stuff around the driver not in the way but fairly accessible . and not to mention would take a massive amount of time to accomplish , just to make a cool toy . your mod is probably far more practical .