Traction Battery SOC "Meta-States"

It's to my understanding though that grid charging only charges the battery to 100%, but doesn't drain it. Correct me if I'm wrong. But from what I've read, I though to restore capacity, that the pack would be drained, then charged full once or twice. Again, I could be totally wrong.

I live in WV, so a full (76-80.5%) charge is seen daily unfortunetly. But when it does that SOC drop from 6 bars, then a few seconds later down to 5, then 4, then 3, it gets kind of annoying. The engine starts to race, MPG goes down cause it's trying to charge it back up to it's normal state. But once it gets there, it's all fine and dandy.

I did use Torque to monitor the 14 block voltages, and they all stayed the same under load and charging. Played very well together. So I know it's not an imbalance issue. I guess it's just age. Even with only 50,000 miles. I thought it may be the 12v battery going bad, because it's the original battery, but I did all the 12v testing and it acts healthy. I plan to change it anyway.

 

I also wonder if corroded buss bars could cause this?

 

i don't see why not.

 

You are correct. For best results on a Toyota battery, we recommend the charger and discharger as a set. This allows for unlimited in car battery refurbishments to be performed. The "Discharge Ready" is required but by itself does not by itself allow the hybrid battery to be discharged. It replaces the standard diode on the car harness with a ceramic fuse assembly. This allows current to be drawn by the battery by a discharger. We are developing an advanced discharger that is not released yet, and we offer a simple discharger on our website now:

This is called a negative recalibration, and is the first sign of poor battery health (and impending failure). By performing an in-car battery refurbishment with our products, you can eliminate the recalibrations typically for several months. By performing a refurbishment a few times a year and charging every 6-18 weeks in between, you can extend the life of the battery for years. If you wait until one of the cells experiences a hard failure, even a refurbishment treatment with our products will not help and you will need to replace the module or the entire pack.

 

I have a generation 3 prius at 78000 km and i am also experiencing this behaviour. Charging would be initiated when the SOC falls to around 39.6% from full, but it would sometime fall all the way down to 30% SOC before the SOC starts increasing again.

 

i didn`t read inaf
but as far as i know battery SOC is usually measured by Volt
V and SOC is effected by Temp
the battery Temp goes up wen in use/charged
this can explain the drop in SOC at the beginning of recharge
recharging heats (makes it hot) the battery more then using it did, and the increase in T drops the V
making it look as a drop in SOC

edit: fixed spelling
wen ill be on a computer whit a spell checker ill try to fix this post

 

some data from torque

Block Highest Volt(Volt), Block Lowest Volt(Volt),SOC(%), # with Max V(Num), # with Min V(Num),Battery power (kW)

15.04 14.91 52.0 0 5 -3.03876
15.08 14.91 51.5 0 11 -2.34951
14.94 14.79 51.0 0 11 -3.28355
15.08 14.92 51.0 0 11 -3.28355
15.21 15.09 50.5 13 11 -3.25591
15.24 15.11 50.5 0 5 -3.51087
15.37 15.26 50.0 0 5 -4.28722
15.59 15.36 49.5 0 11 -5.5827
15.50 15.42 49.5 10 1 -4.51083
15.60 15.41 49.5 0 8 -4.51083
15.59 15.49 49.5 0 5 -4.9631
15.67 15.57 49.5 0 11 -4.06144
15.70 15.56 49.5 0 11 -4.06144
15.75 15.57 49.5 13 7 -2.80207
15.71 15.56 50.0 0 7 -3.45246
15.65 15.53 50.0 0 5 -2.77983
15.67 15.57 50.0 0 5 -2.59904

in this data you can see that even wily KW is going in to the Battery all the time
and the min and max V are going up
SOC is going down

 

Recently I've experienced a big swing in my SOC readings. Many of it actually seems like it's not even a correct reading from what I see on my MFD. When it's really hot out 90+ degrees, the car would show 5 or 6 blue bars but when the AC is running, the engine would kick in when the car is down to 4 or 5 blue bars. It doesn't even reach the bottom of the SOC meter before the engine kicks on. I'm not sure if this is showing weakness in the battery, where the readings that you can see are actually not the correct readings of the ECU that controls when the engine has to kick in to charge the battery.

My car is reaching it's 150k miles warranty limit, it's at 145k miles now. I'm hoping if this is a sign of imminent failure to come, it would come before I drive my next 5000 miles.

 

I have also experienced this in Gen 3 Prius with 90k km, it's not that obvious but enough that I noticed it even before I read this thread.

 

That_prius_car how is your battery doing since your last post concerning the rapid drop in SOC? Any signs of trouble with your hv battery or did you get the hybrid battery charger?

 

I cleaned the corrosion on the bus bar today but coming from a full SOC I still see a rapid fall off in SOC from about 5 or 6 bars down to 2 bars.

 

Yep. I see this on a daily basis. 6 bars would last in EV mode at 35mph for a mile or more before dropping to 5 bars. Then from 5 to 4 within 15s and the engine kicks in to recharge. Sometimes it drops to 3 bars even while charging.