Hybrid fan running at full blast

Hello! Have you noticed any signs of decreased performance? Is it getting you good mileage? Does it seem like it discharges rapidly or takes longer than normal to charge? So, after an hour of driving, the fan comes on. What type of driving for that hour? Are you primarily using the hybrid battery (discharging and charging) at speed less than 46MPH? Or is it an hour of highway use? Sorry for all the questions. There are times that the hybrid battery generates heat and I can't (or shouldn't speculate) on the reconditioned battery and it's overall state, but it is possible there is nothing wrong with the battery. Toyota determines what conditions dictate when the fan comes on and at what speed it runs at, although these conditions can be changed through modifications made with Techstream. It is even possible that the reconditioned battery technician changed the way the fan behaves to run 100% when required. It also may be possible you have a thermocouple that is bad for the battery pack. If the battery does not seem to be suffering in performance and works okay, I would try to gather more information - ie. weather conditions, temperature of the cabin when it happens, etc. If you have access to Techstream, you can connect to the car and access the hybrid battery info. You can check to see if all three thermocouples are close to one another, or if one shows a higher than expected value.
If you don't have Techstream, you won't have access to information that may help you diagnose the problem. You could try to contact whoever installed the battery, explain how happy you were to get a reconditioned battery, but now have something going on. You kind of really have to be gentle here. If the technician has a scan tool that will let him see all the vital info with the battery and will help investigate, that's great. If you have another means of gaining access to the ECU's, then maybe go that route. It might not be a bad idea to contact the company that installed the battery and see if they changed any parameters on how the hybrid fan operates. There is a mod out there that runs the fan at 100% speed anytime it turns on. Maybe they did that?
Sorry to ramble on... Just trying to help. Without more info, it's hard to know what's going on. Hopefully, this helps. Good luck and post back with updates please. Thanks!

 

Try dr Prius app, to see where your battery is at, you'll need a Bluetooth OBD dongle too, Carsista works.

 

Strange how many variations there are. Some don't look so good...

 

The graph appears to show large variances between the blocks, but when I blow up the images to read the values they are not that far off from one another. I wonder if the scale on the graph has been changed from the default values.

In any event, Block #5 appears to be the weakest and if any of them will throw an error message, that would be my guess. An overheating module is caused by a high Internal Resistance in one or more of the 6 battery cells that make up a module. Perhaps only one of the 2 modules in Block #5 is weak. You will note that the IR on Block #5 is higher than all the others, although possibly still within an acceptable range. It is typical to see the innermost modules becoming the weakest because they are the least able to dissipate heat that is generating during charging and discharging, because of their location in the pack. This lack of proper cooling causes even more deterioration and higher IR as time goes by, a vicious cycle.

What kind of warranty do you have on your refurbished battery? As @AtkinsonCycle suggested, perhaps you should contact whoever did the work and ask them if they can perform a re-balancing. Failing that, I see Hybrid Automotive sells a Prolong Battery Charger kit for the Prius C. You may consider ordering that and performing a balancing yourself. There are many members of this forum who have used a similar kit to periodically perform a balancing and have kept their cars on the road for many years after the battery modules began to become unbalanced. You may need to replace a module from time to time, but at least with the kit you can get the most out of the ones you have.

 

An actual temperature reading needs to be taken on the battery itself with an external thermometer to be sure. The hand-held infrared ones are usually quite good.

While it is possible that the temperature sensor(s) have failed, I think it is more likely that you chose the wrong place to get your "new" battery.
If they are reputable, THEY will help you figure it out.

 

Operating temperature of 130 Degrees Fahrenheit is certainly higher than would be optimal for the life of your battery, but apparently these batteries can survive an occasional foray into that neighborhood. My post from 3 years ago appears below. Our battery is still going without any intervention on my part (balancing or anything else), although of course I don't know for sure how long it will be before it decides enough is enough.

58.4 C (137 F) Temp on HV Battery per Torque Pro | PriusChat

 

Yeah I'm with Sam on this one. Verify the actual temperature, make sure the computer isn't being lied to and running the fan in a false response.

Then get up with your battery rebuilder and get them to straighten this out; this is on them to the limits of your agreement with them.

 

Oof! I don’t like the 0.49 voltage difference. I’m honestly surprised it hasn’t tripped a hybrid battery code.

At least on the older Prii, I think the .40-.50 range was the threshold to throw p0a80 code?

Ive got a 13 year old battery with 240k that has less voltage difference even under load. I don’t mean to be a Debbie Downer, but I hope you have warranty on the rebuilt battery.