The Hybrid battery level appears to be higher on my 2007's MFD, when compared to my Scangauge ll. For instance, the MFD will show the pack almost full, yet the Scangauge says it's only 67%. Not sure why this is happening. All I know, is that both gauges used to provide very similar data years ago.
That sounds accurate to me. Note that the graphic on the MFD has a significant amount of hysteresis w.r.t. SOC. Here is the relationship between SOC and the MFD display (not my graph, I got it from some other thread), notice the overlap in SOC % for a given pair of MFD "bars". For instance, the MFD will change from six blue bars to 7 green when the SOC goes above 66.5%, but will not go back to 6 blue until the SOC drops to 63.5%.
That's the way it is supposed to be. Not good to charge the battery to extreme, so the computer just keeps it in the middle of 0-100%. The bar gauge shows the operating range, not the charge per se. X
I find it hard to believe that one bar short of showing a full charge on the MFD, when the Scangauge shows it at 67% is normal. In that instance, the Scangauge used to show it around 90%. At the very least it should be showing 80%.
No, that is correct. The SOC operating range of the hybrid battery is 40%-80%. At 80%, it starts aggressively trying to discharge the battery (by spinning the dead ICE if needed). 67% is indeed a relatively high SOC. 60% is the target value the ECU tries to maintain. It does this to prolong the service life of the NiMH battery.
But again, it used to show just about the same SOC as the Scangauge. Even with the MFD showing the battery level at 50%, the Scangauge shows it much much less.
The Prius system and MFD display assumes the battery is at full charge at an actual figure of 80% charge. It is never charged higher than this. The discharge limit is 40% and this would be represented by no bars displayed or zero charge on the MFD again the maximum discharge the system will allow. John (Britprius)
The limits set by Toyota in my previous post greatly improve the cycle life of the HV battery. If the battery was fully charged and discharged it's cycle life would likely be around 1000. John (Britprius)
