HV battery output comparison (new OEM vs. 12 year old, 170K)

I did a battery comparison on a new OEM HV battery in a 2005 Prius vs. an original OEM HV battery in a 2004 Prius. I tested both under hard acceleration and braking situations.

2004 Prius original OEM HV battery (170K miles on the car and the battery)
graph: click here
average = 17.2v, standard deviation = 0.9v, min = 14.3v, maximum = 18.3v, delta volts = 4.0v
min = -72.2A, max = 98.0A, delta amps = 170.2A
peak power output: 20.16 kW @ 66% SOC

2005 Prius brand new OEM HV battery (108K miles on the car, ~ 100 miles on the battery)
graph: click here
average = 15.3v, standard deviation = 2.1v, min = 12.7v, max = 18.6v, delta volts = 6.0v
min = -98.8A, max = 149.0A, delta amps = 247.8A
peak power output: 26.99 kW @ 66.5% SOC

I compared the new OEM 2005 HV battery power at peak (26.99 kW at 66.5% state of charge) vs. the old working 2004 HV battery at peak (20.16 kW at 66% state of charge). The old 2004 HV battery is showing a 41% degradation in power output vs. the new 2005 HV battery. This test was by no means scientific (two different cars, different acceleration and deceleration characteristics, and slightly different SOCs). I just gunned each car and then braked as hard as I could without tripping the hydraulic brakes.

I read some where that the gen 2 HV battery outputs 20kW at 50% SOC. So this makes me wonder if my old battery is still performing fairly well (@ 20kW @ 66% SOC, not 50% SOC) and the new battery has design improvements that has boosted output (@ 66.5% SOC, not 50% SOC)? Thoughts anyone?

As long as the 2004 HV battery modules are performing more or less the same on the voltage swings, no DTCs will be set.

(Note I updated this section to more properly compare the two batteries based on peak power.)

 

Too early to tell. I need to get through several tanks of gas before I can say for sure. My off the cuff is that I think they are going to be similar since I rarely do hard acceleration.

 

Yes I used Techstream. I modified my comparison in the original post to compare peak power, not amperage. Based on that comparison, the old battery is down 41% from peak power of the new battery. This test was by no means scientific (two different cars, different acceleration and deceleration characteristics, and slightly different SOCs). I just gunned each car and then braked as hard as I could without tripping the hydraulic brakes.

"I compared the new OEM 2005 HV battery power at peak (26.99 KW at 66.5% state of charge) vs. the old working 2004 HV battery (20.16 KW at 66% state of charge). The old 2004 battery is showing a 41% degradation in power output vs. the new 2005."

 

There are sensors in the car that controls when hydraulic brakes kick in (the yaw rate and deceleration sensors). If everything is normal the car switches to hydraulic brakes when stopping at speeds below 7 mph (if I remember correctly). I was able to determine the switching point by monitoring at the regeneration current going to the battery. I am sure there is a direct way to do this by monitoring the output of the yaw rate and deceleration sensors.