2006 Battery internal resistance

What part of the graph makes you uncomfortable? The IR range? Most are 28-31 (pretty normal for a used battery) with block 10 being an outlier at 33?

If memory serves, I'm pretty sure block 10 is where the safety disconnect plug taps into the circuit. I don't think a mohm or 2 is out of the norm for that extra path.

 

If you are talking about the "Manhatten" graph of the voltages, that looks worse than it is because of the way the app dynamically sets the Y-axis range. There is only a 0.07 V difference** between the highest value and the lowest value on that chart. If the Y-axis values were set to 10 V to 20 V the tops of those bars would almost level right across and you wouldn't give it a second thought.

Having said that your screenshot shows no current either in or out so it is not really telling you a lot. You need to screenshot when it is drawing 20 A (or more) out (accelerating) and then another one with the same with 20 A or more going in (decelerating/braking) to get a useful picture of your battery.


** Interestingly when I calculate the difference I get 0.15 V between the highest to lowest. Even so, it is nothing relatively speaking.

 

What specifically do you notice that makes you think "the battery's no good"?

Posted via the PriusChat mobile app.

 

You have an app that was developed by an enthusiast/app developer, not a Toyota engineer. I don't know that I would get too worried about the color coding he decided to use and assign to various IR values. Your numbers are not out of the norm. If you had the numbers you have and an outlier at 36-38 or something, I would say worry.