Hello Friends I have a 2010 Prius , the HV battery had some issues and i replaced 4 cells in it , while monitoring the battery I found out that block 5 resistance is higher than the remaining blocks ( for Example Block 5 is 28milliohm while all the remaining blocks are in the range of 22-23 milliohm using Dr.prius App and these values reach the 34 milliohm for block 5 while the remaining block never exceeds the 28milliohm value) i thought there is an issue with the cells it self since i already cleaned the busbars properly , so i changed the cell with different ones however the values for the same block are still higher than the remaining blocks , thus i changed the position of 2 blocks (block 5 and 6) to check the issue however even after the changing block 5 still reads the highest values (Cells in Block 6 was 22 milliohm before the change and it reached 29 milliohm after i installed them on block 5) so i was wondering what might be the causes for the high resistance values only on block 5 ? how does the system read the milliohm values ? and what can i do to rectify this issue ? thank you in advance
It computes the block's internal resistance by observing the block's voltage when no current is flowing, and then observing how much that voltage drops when a known current flows. The voltage drop divided by the current is the resistance. By looking at the voltage drop as soon as practical after the no-current voltage, the ECU tries to get just the drop due to internal resistance, and not due to discharge of the block.
thank you for these information's , so it detects the internal resistance when i start accelerating the car right ? and does it keep detecting it regularly ? or only one time ?
My assumption is that it updates the values regularly while driving. But the battery ECU firmware is not published.
