Battery cooling fan

Here is the TL;DR version copied from below: Is it completely normal for the middle battery sensor to read 116°F and its cooling fan remain on the lowest setting?

Hello all, I have searched the forum and not found an answer to this question. At what battery temperature should the cooling fan activate for each fan level? I was trying to diagnose my GF's issue today. She had the RTD and so on, so I hooked up Techstream and got the following codes: P3000, U0100, U0111, & P0A80. I also noticed that battery block Vol 06 was considerably lower than the rest and assumed I would be refurbing the battery as I had done to my own several times now.

However, I chose to look at that last code first, P0A80 (batt. overheat), assuming it could be the cause of the other codes as well as the cause of the lower voltage on block 06. So I hooked up Techstream and tested the battery cooling fan, I could hear it cycle between all 6 fan speeds as I hit the button. I did not inspect the fan but I did put my hand down in the aux battery compartment where the cooling fan exhaust and felt a significant breeze.

The following day I cleared the codes, and with the car and battery completely cooled, drove around for over an hour with techstream providing live feedback (mountainous roads, about 50 degrees F). I was watching voltage on battery blocks (mainly highest vs lowest) they seemed ok (block 06 was now back in line with the rest). The highest and lowest remained within 0.5v of each other, not sure if that is great but it drove great and no codes were triggered.

I then focused on the battery temp. It took a lot of driving and I even rolled up all windows and blasted max heat into the cabin but the temp of the middle sensor finally climbed as high as 116. Several times as this heat was slowly rising, I left the car running and got out to put my ear to the battery fan vent. Every time it sounded like it was on level 1, 2 at the most, even with the battery temp at 116. A quick google search had provided me with the information that they liked a max temp 110 (did not research this heavily as I was driving) and so I assumed I would be hearing the fan speed step up as it rose above 110 or probably even before. However, at 116, the fan stayed right on the low speed. FYI, the other two sensors stayed within 3 and 5 degrees of the middle one.

I have researched several things I can check into regarding the fan but most seem more an issue of it spinning or not spinning rather than an inability to spin faster when needed. I guess my question is do I need to look at these things or is it completely normal for the middle battery sensor to read 116°F and its cooling fan remain on the lowest setting? Does anyone know the temperature required to put this fan into its highest setting? I hate to root around in there for nothing and I was not able to get any code to trigger again despite my best effort. She says their was nothing blocking the vent when this occurred. I'm inclined to believe that since there is nothing in the backseat at all. Unlikely, but not impossible something from the rear storage area draped over the seat and vent area? But I'm feeling like the fan is not activating a higher blower setting when it should, but don't know why.

 

I probably will do that but what is weird to me is that even if debris is causing it to overheat, why does the fan continue to only spin at the slowest speed, why doesn't it try to cool it? Battery ECU? Fan relay?

 

One of the first things I did, described above in too much detail for some and not enough for others, lol

 

So I'm realizing that part of my confusion is that I confused P0A80 for P0A85. In reading a post I must have scanned over the code too fast to see the subtle difference. I believed my code was battery over heating (P0A85) when it in fact was not. That's what had led me to investigate the cooling fan, and that led to discovering it remained on low with the battery reading 116F. I'm still curious if that is normal, can anyone tell me what the operating temp should be, what temp is the battery ECU attempting to maintain? That is secondary now, as my battery never overheated after all and I have to assume it is operating normally until informed otherwise.

On to the actual issue of P0A80. My initial check showed block 06 at 12.61v with the others ranging from 13.99 to 14.44, an obvious problem that led me to immediately clean out my own Prius so my GF could use it to finish out the work day/week (or possibly several weeks as I well know now). What confuses me is that upon clearing the codes everything seems to pass with flying colors (ok, good enough colors). I have run Techstrem live while driving several longish trips (1.5, .75, and .75 hours) each block has stayed reasonable balanced, never more than .5 volts between highest and lowest and usually less. Furthermore, I kept an eye on which block was currently lowest volts (again, on a currently live updating data readout) and it constantly changed, indicating no block was consistently weaker than the rest while under load. Block 06 has not indicated low voltage since my initial scan. Perhaps of no concern, but temperature also remained pretty solid and I was only able to get up to 116 with considerable effort (coasting, braking, attempting to charge as often as possible, as well as blasting max heat into the cabin), and I'm still unclear as to whether 116 is high, or completely normal and undeserving of a higher fan speed.

I look forward to any advice, I see now that I began down the wrong path. For the time being, unless someone informs me that 116 is too high, I will assume the cooling fan is working as it should. I will continue driving my GF's car, and she mine, so I can keep an eye on things, but I don't see any action I can take until a code reappears.

UPDATE: I hooked up techstream, put it on live data for the HV battery and watched the voltages again. This time however, I did not drive around but instead put it in neutral (with the car running/ready mode) and turned on every power drain I could think of (AC, high beams, rear defrost, etc.). With no charging, and only drain, I watched the battery block voltages. Once the bars where in the red, block 6 did became and remain the lowest voltage, tho only by a fraction of what it had been upon the initial scan. I continued draining til the car warned me to put it in park so the battery could charge. At this point there was only a 0.73V difference between the weakest block (block 06) and the highest block. No codes were triggered. I'll attach screen shots of Techstream, all but one will be from the intitial scan within minutes of the RTD and all codes still active. The other will be the most recent HV data while I was just doing the drain test. It was taken prior to block 06 becoming and remaining the weakest however.

Is a 0.73v difference indicative of a bad cell? Obviously when it read 12.6v and others being 14v that would trigger a code and be cause for alarm, but I can't get it to do that again even with pushing the car much further than it would naturally go in regular driving. Would a 24 hour grid charge be advisable or just briefly prolong how long I'll need to wait to see the code again? It seems a few of my codes are related to ECU communication, could the battery ECU be intermittently faulty?

Thanks to all!

 

There are three sensors, they seem to be working fine. I misread a post a now realize my battery never actually overheated.

 

Good point, I will probably do that. But first, here is something to consider (see video). I did some searching of my browser history yesterday to see what led me down the wrong path. Here is a compelling video involving a P0A80 code that was a result of a clogged fan and overheated battery and the battery was fine in the end. I know my fan is not clogged, but if it is not speeding up when it should... same result.

In this video, the owner drove the car with the issue for some time before bringing it in to the mechanic and yet battery was fine. Seems very similar to my issue except I caught and am addressing mine immediately. I'm not convinced cooling fan is completely ruled out.

 

I must confess, I do not know how to change the title This is far from my first time but it's crazy how far we will go to convince ourselves it's anything else, lol!. Going to look for corroded connectors at the battery ECU and wire harness (still trying I guess), but I am resigned to most likely refurbing the battery.

Mr Guy Mann, does this statement mean "cycling a few drains and grid charges to refurbish my current modules or just replace the bad module(s)" or do you mean "refurbish the battery by replacing bad module(s) or replace with entirely new battery".

Thanks everyone for bringing me back down to earth!

 

First, can someone please explain to me how to change the title of this thread? I definitely got it wrong.

Second, I have done all the testing of the modules and collected data. I did three charge/discharge cycles. 1st to 134v, 2nd to 101v and last discharge to 84v. I took individual voltage readings at specific intervals with each discharge. Data got a little less complete by the final discharge, hopefully the first two will paint a clear enough picture. I then used a battery analyzer to retrieve more data from each module. I was attempting to drain each module to 6v while analyzing but a few got away from me and drained lower (it was so erratic)! I have to admit, this last set of data means very little to me (due to my lack of knowledge). The discharge data is a little more understandable to me, but I still would like some opinions on which modules to replace. Its pretty clear to me that #11 is bad and is in the battery block that was originally indicated by Techstream to be the weak block, there is a chance that I ruined #27 (after the first three pages of data were collected, in the battery analyzer procedure). #14 is suspect. Are there more?

I'm wondering if anyone can look over this data and give me their opinion on which modules need to replace, as well as their opinion of the overall health of the remaining modules. I have a suspicion about this battery. We bought a Prius (our second) at a used lot and it came with a fairly new refurb battery with most of a year left on the warranty. Well a few months later it died and they were quick to give us another with the few months remaining on the original warranty, which is standard I believe. My suspicion is that they put together packs with the weakest left over modules that they figure will last just long enough to finish out the warranties left on returned batteries. Because that is exactly how long this "fresh" refurbed battery lasted, a few months, within weeks of the warranty of the original warranties end date. I would not be surprised if all or most the modules look to have little longevity left to them but I do not understand the battery analyzer data well enough to make any determinations, so I will refrain from naming the company at this point.

Thanks in advance. If anyone knows someone who would be able to perform this data reading I would be grateful if you called their attention to this post.