I recently overhauled and cleaned the traction batteries on both my two 2007 Prii, and my wife's car is still having issues with the traction battery running hot, like 120-130F range. She was also complaining the car is gutless, couldn't maintain 70 MPH for more than a minute. The battery cooling fan and ducts are clean and it seems to be flowing pretty decent airflow, but the fan doesn't go to maximum speed soon enough in my opinion. While rebalancing and charging the cells (replaced two cells)then grid charging the whole pack after reassembly, I silver-plated (much better conductivity than nickel) all the busbars and also had to replace the Battery Control Module and its associated harness to the cells due to corrosion of the BCM plug and subsequent loss of several of its connector pins. After replacing the Bosch Iridium sparkplugs, one of which was burned round to 0.050+ gap with new Denso Iridium SK16R11 directly from NAPA Auto Parts store, took the car out to warm up on a test drive and ran Dr. Prius Life Expectancy tests, which showed the "Battery pack has estimated 87.53% capacity left, it is in good condition", and Full Battery Test which also showed pretty good. First test was the Full Battery Test, good, but in red, "Warning! Poor balance block #13, #14" then the Life expectancy test, 87.53%, then another Full Battery Test, which showed "Battery running warm" (Dr. Prius Battery monitor at that point said approximately 120F or so across the board, to be expected after testing, I think). I guess we will find out tomorrow on a trip to the big city of Portland OR, 90 miles each way, whether the tune-up consisting of new plugs, MAF/ throttle body / filter / <edit PCV> (not EGR) cleaning (none particularly dirty besides the plugs) helps. This car had also dropped MPG's into the low 30's also. Wondering what else to check? Oh, while plugs were out, did compression test, 150-155 across the board, which seems pretty good. Wife says check fuel pressure, but is there a place in Techstream, Torque or other app to see fuel pressure? Or do I have to glom together a pressure gauge somewhere in the fuel line like I read about online last night? I'm thinking of pulling the injector rail and drilling/tapping a schrader valve into it like so many other cars already have from the factory. And why did Toyota make the fuel filter part of the stupid fuel bladder tank?? Non-serviceable?! Really???
i would get oem plugs from a dealer because of the proliferation of chinese fakes. the battery is likely weak and in need of replacement because of all the old cells
According to Dr. Prius, the battery is at I think 87%, which is very good. I just installed last night Denso Iridium plugs purchased at my local NAPA, which should be reputable parts. That's why I didn't go Amazon, I was really worried about the proliferation of so many counterfeit things currently on Amazon.
Is 120° seriously warm for the traction battery that many sales that many amp hours battery chemistry and all that I'm just asking it seems awfully low 120 that's like just above the temperature of outside in a lot of places in the USA It just seems to me like it would be more like 1:30 140ish I mean anything can run at those temperatures that's nothing I mean it might be to a human being but the plastics and battery and electricity I would think $140° wouldn't be squat what is my big fancy wire for my hot tub rated 90° C what is that I don't know the conversion that quick that's like 180° or something? I don't know It just seems awfully low 120 seems really I don't know like I wouldn't be worried about it when I touch my battery pack every so often in the back of the car it's a tad warmer than I am or I wouldn't feel the heat right But nothing that makes me think anything no smells nothing happening that's what I go by when things don't smell right electricity gets warm enough you start getting that ozone smell
It wouldn't hurt to verify that the duct work around the HV battery is put together correctly. Maybe pull off the very last piece, the one that goes in front of the auxiliary battery to the side of the car and verify that it is blowing hot air out at a reasonable rate. Poke the little flaps in the side of the car which are suppose to blow open to verify that nothing has glued them shut. Do you have a laser thermometer? It might be interesting to pull everything out of the trunk, drive the car around until the HV reads hot, then take a quick set of temperature readings down the side of the battery. If something inside is heating up abnormally then you might see a hot spot which is averaging out to "too hot" as the heat spreads across the battery, but is actually a bigger problem (as in, way too hot at that location.) The laser thermometer can be done safely with the car running. If you don't have one turn the car off and I guess just use your hand to quickly feel along the side of the battery. But if there really is something way too hot burning yourself is a possibility with that method.
I once logged the HV battery fan speed and battery temperatures while driving over a few mountain passes, and this is what I came up with: HV Battery Fan Speed Transition Temperatures 2007 Toyota Prius Extrapolated from OBD logger data Approximate reading of highest temperature sensor 0 to 1 @ 36° C 1 to 0 @ 34° C 1 to 2 @ 39° C 2 to 1 @ 37° C 2 to 3 @ 42 °C 3 to 2 @ 40 °C 3 to 4 @ 50° C 4 to 3 @ 48° C 4 to 5 @ 52° C (reduced battery current limit) 5 to 4 @ 50° C 5 to 6 @ 56° C 6 to 5 @ 54° C Note that the fan speed is reduced when the battery temperature drops back down to 54°C (129°F), implying that Toyota engineers considered that temperature to be safe enough that maximum fan speed is no longer necessary.
I wonder if the transitions are purely triggered by the temperature or if there is also a time component. That is, it drops down a speed instantaneously at 50C, but if it then sits there (like at 49.5C) for so many minutes maybe it goes back up again? 50C might be fine for 2 or 3 minutes, maybe not so much for 30 minutes.
The fuel filter never clogs. Some of the fuel pumps are known to seize. The fuel pump filter and sensor assembly is about $800 as a kit. The only way you can replace the parts separately is to read the part number off the Mitsubishi fuel pump and order it on eBay and then change the connectors. But this is not your problem that you are experiencing. The pressure is fine if you don't have any codes. You are running techstream to perform all diagnostics right? Aside: I need a new OBD dongle. Which do you guys recommend?
The traction battery fan is venting at the right rear corner by the 12 volt accessory battery. I guess they didn't want to recirculate that into the cabin. There are noxious gases from it so running the fan at high speed does waste air conditioning. I can kind of see their point. However I would like to see the fan speed slightly higher to allow full region braking. Is that the best balance given this concern?
There is probably a way to crank up the fan, but keep in mind that the faster it spins, the faster it is going to wear out. One from a junk yard will be just as old (more or less) as the one you would be replacing. A new OEM one has an MSRP of $444 (but is available for $333 at a dealer near me.) Not cheap. Dorman sells one for $228, maybe it is OK? Not a huge fan (joke!) of that brand - OK for chunks of plastic, metal, and rubber, don't trust them much for anything more complicated. Can't just change the motor on the fan because the cage is more or less permanently attached to the shaft. Molded on or pressed on, I can't tell which.
Yes, I have a laser thermometer, and access to a high end FLIR camera that I could borrow. I often use Techstream, Dr. Prius, and Hybrid Assistant, which has an easy fan speed control function. I also have Torque Pro, but use that more for just engine-related stuff, not battery stuff. Techstream is on a dedicated small laptop, the others run on my phone and a tablet I have set up with those apps, along with both OBDLink MX or KonnweiOBD, depending on which Prius I happen to be driving. Both bluetooth obd2 devices work well with those apps. I may pull the carpet and floor hatch cover off before my drive to work this week so I can get a better shot at the battery in my wife's car which I'm going to drive for a day or two to figure this temperature thing out. Today's drive took the battery to about 120F. Interestingly, Dr Prius rated the car with the hotter battery higher healthwise. I'll have to take Pasadena's advice and reinspect the ductwork, especially the exhaust side by the 12v battery. I did check this weekend if the fan had a blockage by momentarily putting a piece of paper over the inlet in the back seat, and it sucked in place quickly, so there's at least pretty good airflow from the inlet to the fan motor. I would have thought the weaker battery in the other car would have been the one to be getting hotter. BTW, in my day job, I work on extreme high voltage equipment, as in 500kV to 1MV (big M, not little m) AC/DC, and we have some station batteries that weigh considerably more than both my cars combined that I work on annually, so I know my way around sparky stuff . I'm thinking that FLIR camera might be the better option.
Attempted to use Dr Prius today in the cheap Chinese crap that I plugged into my car made the car throw codes. As if I already didn't have any faith in cheap Chinese crap already this really put icing on the cake. So I took a sledgehammer to the Chinese crap and put it in its place. It's probably spyware from the government of China Just like tick tock anyway
For basic stuff like Dr Prius I use the BAFX products device (bluetooth version with my android phone). Posted via the PriusChat mobile app.
Absolutely. I didn't bring that up as a possibility because hardly anybody has access to that technology. (Just looked and these devices have come down quite a bit in price. Still, the least expensive ones are still around $200, and who knows how good those are.)
From what I can tell from my logs, which I usually set to record every ten seconds, the fan speed transitions are within a few seconds of reaching the battery temperature transition points. When the fan transitions to the next higher speed, it continues to run at that speed until it cools two degrees Celsius below the temperature where it sped up. So for all practical purposes, the transitions are purely triggered by the temperature and there is no time component. At 50°C the fan speeds up from speed 3 to speed 4, and doesn't go back down to speed 3 until the temperature goes back down to 48°C. Then the fan speed will not go up to 4 again until the temperature goes back up to 50°C again.
I think it's probably the best balance for the average driving profile and average climate. But, if under your specific conditions, you are missing out on a considerable amount of regen braking due to high battery temperatures, then a higher fan speed might be the better balance for you.
