how do you read dr. prius app

Take a look at the videos on the app's website.
Hybrid battery diagnostic and repair tool for Toyota and Lexus

When battery is under load it is easiest to see issues. Sitting at rest is not as helpful to look at.

Voltage difference
Basically want diff between highest and lowest to be very small. All similar is good. A couple's of tenths difference maximum would be nice.
A volt or more is terrible.
It's sometimes hard to watch this since the graph is constantly rescaling.

IR will never be 0.
Basically best if all similar.

Better to have a battery where all the modules are crappy, but equally crappy, than a battery with mix of excellent modules and marginal modules. Too much difference between modules will make the car freak out.

 

Call me and I'll walk you through it.

If you feel like it, you could document it for yourself or others.

608-729-4082

 

I have the same question ~ what am I looking at here???
2014 prius V 5

 

The same reply.
Call me.
Then you can write it up and document it if you like.

 

You want the voltage difference between individual cells to be low. If it was 0.4v-1.5v it might be closer to end of life. You also want the individual cell resistances to be almost equal. Yours looks reasonable.

The rest is just realtime data that is not useful unless the battery is not working at all, typically if it sat in a junkyard for years.

The clearer screen is the full battery test. Some believe this load test is a decent method to test the battery. However reduced mpg by 10% or more and a rapid discharge in a couple of minutes is a good indication the battery is old even if the error codes have not come up yet.

Honestly all of this is meaningless unless you have the battery fail codes. Detailed cell by cell data is of questionable utility from a repair standpoint unless you were a refurb company swapping modules. Even then a simple voltmeter would be the tool of choice.

The following pic is a good battery with a couple of years use. Typically you should get at least 8-10 years. Voltage difference is low and the cell individual resistances are equal. However even these numbers will fluctuate when the battery is loaded.


On the first screenshot from post 3, you can see a higher voltage difference and a resistance difference that Dr Prius believes is out of range.

 

Even if it means matching weaker modules with better modules to average out the blocks????

 

Hello Eric May I request a 2008 Prius Battery consult?
423-526-132eight
kennethwinter65@gmail

 

I called you a little bit ago but got voicemail call me at 608-729-4082

 

Hey Eric.
I wanted to seek your opinion on what did not work on my 2008 battery rebuild..

Attached are my testing and Dr prius results

 

In that picture it seems like block 11 is quite bad / low, you might want to replace the 2 cells on it.

 

Does the Dr Prius app give any indication of the health of the 12v battery? I can't find it if it does.

 

No. A load test at an auto supply is the best way. Requires removing the battery. Some try pseudo load tests using headlights or measured voltage differences overnight but those techniques are less reliable.

 

Would anyone be able to tell me if these numbers from my Dr Prius app are showing if my traction battery is good or bad?

Vol#1 Vol#2 Vol#3 Vol#4 Vol#5 Vol#6 Vol#7 Vol#8 Vol#9 Vol#10 Vol#11 Vol#12 Vol#13 Vol#14
16.06 16.01 16.06 16.06 15.88 15.87 15.94 15.94 16.01 16.01 15.99 15.96 15.92 15.94

IR#1 IR#2 IR#3 IR#4 IR#5 IR#6 IR#7 IR#8 IR#9 IR#10 IR#11 IR#12 IR#13 IR#14
23 22 22 21 21 21 21 21 22 22 22 22 23 24
22 22 21 21 21 21 21 21 21 21 21 21 22 23

SOC(%)
58.4378
58.4378

 

The real question is what makes you think the battery is weak or failing? Symptoms are more important than rapidly changing data points from an app.

A fairly new battery looks something like this with the important numbers highlighted.

The closer each cell is to each other judged by voltage difference and internal resistance, the better. Yours are probably just ok. You also don't want the battery temps very high, ideally around ambient temps on a hot day.

But all this is insignificant and misleading if the battery charge is lost quickly in a couple of minutes waiting at a stoplight with the ac on. That is a symptom. The state of charge is not all that important if it stays above 40% and shows close to full bars on your dash when driving normally, eg not in stop and go traffic. Discharging fast is an important symptom to recognize.

There are a few things like corroded bus bars that could reduce capacity and make the numbers look worse. If the battery is original at ten years or a "reconditioned, refurbished, repainted" or just plain mix and match used replacement, new cells are the answer - especially if you are getting a battery code, the worst symptom. Knowing what the codes are is more important than any of these data points. No codes or symptoms? You are good for now.

 

Thanks for that info. The battery does empty out quicker than it did in stop and go traffic, within 10 minutes it is recharging for sure. I have noticed my Liters/ 100kl has gone from a pretty consistent 4.5 up to 4.9 -5.0. Wondering if that could be evidence of the EGR valve? The car is 2012 and has 260,000 Klm with no real maintenance except oil changes.

 

Ten minutes is ok, you will notice it does not charge much under those conditions, creating more frequent cycles. A two minute discharge is the real warning sign before battery codes appear. A weak hv battery will lower gas mileage as well. These engines tend to build up carbon in the egr, head and valve passages and accumulate pcv liquids in the intake manifold. Cleaning all the carbon is difficult in the head and intake passages but egr cleaning is a tax exempt religion around here.

 

Hi Eric, this is an old thread I know, but I'm wondering if you're still helping people figure out what they're seeing on there and Dr. Prius results? Thank you