The battery fires at ECU sense connector thread

That is the first thing I thought of. What happened to those four modules to set them apart from the rest of the pack?

Brad

 

At the last the last burnt up connector modules 1 to 4 had been drained. This made me realize something. There is 32 volts between pins 22 and 21. Between pins 22 and 11 there is 16 volts. 32 volts is too much for the distance between pins 22 and 21. 16 volts is ok for the distance between pins 22 and 11.

This does not explain why some other pins will randomly grow malachite.

Brad

 

Just to add my 2 cents here...perhaps someone can work this information further to get some explanation.

This evening i had a friend invite me over, and while at it, he went on on how he had just pulled P3000 from using a scan tool. Since it was sub 123 as i checked with my T/S, we went ahead to disassemble the HV battery to reveal the battery ECU in place for observation. We visually inspected the orange connector going into the battery ECU and observed that it was already getting burnt up cos it had some black visible marks around some parts of it.

Next, we tried to get the car ready and got a P0A0D code, i inserted the service grip plug firmer and it got ready after two or three tries, then a P0A84 set. Friend confirmed haven pulled this code (P0A84) a week earlier but code went off by itself after he'd driven for a while.

With P0A84 set, i could not successfully drive the hv battery cooling fan past 2 using T/S, it gave a communication error...long story short following the diagnostic tree, we traced the fault to a failed battery fan fuse.

Will a broken bat fan fuse cause a faulty ground connection?
Why would the P0A84 set intermittently if it can potentially lead to a burnt ECU, i would expect that the ECU monitoring strategy will be frequent for such issues?

 

.......

 

Hey, how do i delete this reduntant post?

 

You can use the report function and ask a moderator to delete it, or edit it and select all and replace all text with a fullstop/period.

 

I do hope that that tiny bit of lubricant will help prevent corrosion and lengthen the health of the battery connections.

I live near Augusta, Georgia where we see some of the same moisture indications (algae, mildew) that I have seen on trips to Florida. Because of the recent changes in global weather patterns surfacing here, I have experienced unusual failures in electrical contacts. In one significant instance, I tried wiping, (91% IPA) alcohol and a q-tip, then finally filing the contacts (this also removes chrome plating!) to get a garage clicker to work. I opted to put a tiny bit of 3-in-1 oil on the exposed brass where I filed away the plating. We'll see how long that lasts.

Next, after putting up with a computer mouse that was becoming unusably erratic that it would literally jam the input (mouse and keyboard) on the computer to the point that even rebooting would not help (but the bleachbit app did), I checked the battery several times. The usual tricks did not work - removing and replacing the batteries failed to help. Wiping the batteries on my jeans failed as well. Spinning the batteries in place to remove corrosion did not work. Finally, on impulse, I sprayed the battery ends and the contacts with my electrical contact cleaner and was shocked that the cleaner DID work!

Since then, I have gone to my TV & internet cable junction on the side of the garage and disassembled the splitter connections, sprayed them and reassembled the lot resulting in a dramatic drop in correctable and uncorrectable errors showing up on the cable modem status page. This led to more low-voltage connection spraying around the house with yet more to do.

All this has appealed to my superstitious/intuitive sense that I now have the hypothesis that these problems associated with failing low-voltage connections are not just connected to moisture and corrosion, but also to species of microbes which thrive on the heat generated by, and may even actively promote, poor connections. The terms electrobes or lectrobes might be appropriate.

Alcohol should work against the electrobes but apparently electrical contact cleaner works better. Time will tell how effective contact cleaner works, but I definitely will be using it when I reassemble my Prius battery.

 

The 32 Volt difference would indicate that there is some shorting happening or perhaps that some sensor wire contacts have been mistakenly placed. The only sure way to determine the cause would be by performing actual forensics on the battery.

An electric potential and a little moisture in the air, especially salt air near the ocean, might over time create copper carbonate deposits. These have certainly been reported as being around the bus bars of some Prius hybrid batteries and the cause attributed to the release of corrosive chemicals by stressed or leaking batteries.

 

The 32 volt potential between pins 21 and 22 is by design. Pin 22 is connected to the most negative battery module. Pin 21 connects to the positive side of the fourth module. Four modules at 8 volts each is 32 volts. When pins 21 and 22 shorted the fire was the result.

Brad

 

My bad. So the pin number has nothing to do with the module number.
Thanks, Brad.

 

Found the AMP receptacle part number for the orange battery sense harness.
316836-1 tin, gold is available but 6k min. digikey has inventory

 

Okay, this is a VERY interesting thread for vintage Prius owners (like me).
On the green crud, here is a link to some contact chemistry discussions:
What is the green corrosion on battery terminals? | Hearth.com Forums Home

Now, the fact that certain terminals are (a) corroding and (b) subsequently burning the plastic pin housing indicates that current is being drawn through the pin-with-corrosion, AND the comment in the thread (linked above) that "green crud" / copper sulfate is a fair conductor when cold but a poorer conductor when warm suggests that these failure should be more common in the North American summer than other times of year. That the pin housings are burning indicates that a significant amount of heat is being generated at the pin male-to-female interfaces. I suspect (will investigate) that the char and burn temperature of the orange plastic (which probably contains flame inhibitor compounds, like bromine) is about 400C.

In all the pictures, I see NO signs of arcing. (background: I used to work in the high voltage/low current business, and arcs leave characteristic marks when they occur. ) Just burned plastic and corroded contacts. The breakdown potential of dry air is 10v/micron, so it's about 10kv necessary to draw an arc over a 1mm gap. Even derating for damp/ion-infested air, the maximum battery voltage is 1/30th the air breakdown potential... plenty of safety factor, there.

So I would conclude that the contacts got fairly hot, but below the ignition temperature (or ignition was frustrated by chemistry of flame retardants), and stayed there for a significant length of time. What I see is charred (blackened) plastic. What I conclude is the contacts were conductive enough to appear (to the system) to be performing normally, but in fact were carrying enough current for a period of time to let ohmic heating (P=R*I^2) char the plastic.

Comments from anyone with fire investigation experience would be helpful.

Preventive maintenance: cleaning the contacts BEFORE there is a problem is presumed helpful.
Here is a link to one contact cleaner spray. Not an advert or recommendation, but a helpful link.
Electronic Contact Cleaner - WD-40 Specialist
This page has links to the MSDS and technical performance data of the contact cleaner, so you have an idea what you're dealing with.

I actually am working on a 14 year old Gen I Prius (inverter pump replacement), so when that job is done, I will inspect and report the Battery ECU plug condition. Come to think about it, the traction battery was replaced on this car about 4 years ago... but I will see, anyway.

 

Chapman. Wanna thank you for starting this thread.

I have also wondered y would those connectors to the ECU get that terribly damaged, and even result into a fire?

Here's an experience I had sometimes ago.
I had this Camry, 2009, with about 145000mikes on em.

Here were the symptoms when it came to my place:

1. Intermittently stops while driving

2. Starts only when the engine is cold. That suggests to me, some kind of electrical/electronic circuitry issue, or even a shirted battery maybe.

3. Techstreamed it, discovered a whole a lot of codes, including replace hybrid pack, and so on.

4. What amzed me during the live data analysis was that on a particular block, the voltages were flucting from a positive 15.., to negative 15....as Texas hybrid batteries stated.

5. Removed the battery pack, gradually tested them(open circuit test), then under load, using a 55W headlight bulb. I had thought it could ne one of the modules. But after the load tests, delta V between modules were just almost 0.00-0.01V.

That made me realised that thus isn't a module proby, but something to do with the voltage sensing wires.

Committed looked at the wirings, they were OK. Then decided OK, check the connector to the ECU. Lo and behold, about two of the ECU pinouts were kind of like burnt/corroded.

Decided to open up the PCB, and solder the pinouts and clean them with dielectric grease.

Car works perfectly now, without erratic readings on tech stream.

Have being thinking what on earth could cause this?

My conclusion kinda tells me might be a design flaw.

PS: Buss bars were corroded though. Cleaned them up with emery cloth, greases them lightly, and coupled them.

***Flooded battery compartments can also cause this problem.


Dxta

 

Aha! Isopropyl alcohol. That's something I'd consider using next time too. I normally use dielectric grease. Maybe, would use the dielectric grease, then wile them off with the alcohol.

Well, I'm kinda scares what impact that might have, seeing one using both.

 

Wao! It just seems like you and I did the same job. I don't replaced part just for the sake; it must be broken before I replace.

Same thing with my friend's Camry. Dealership wanted to replace the complete pack

 

My orange plug shorted out also.
Build 2003 November Gen 2.
Brought 2nd hand "working, and starts every time I'm not there". Battery ecu works just fine other than the vapourised pins giving it miss leading information such as negative voltages either side of module and 24 plus volts on one module. Once open up tested all cells were within 0.3 volt open circuit voltage.
Heavy corrosion on bus bars too. They have been all cleaned up up and silver plated, waiting on return of busbars for install. New sense wire harness and 2 new battery computers to test. One from 2005 same part number, the other from a 2009 with the latest firmware.
error code for those interest
P3000 ( sub code 123) battery ECU is producing an abnormal signal
P3030 - High Voltage Line Snapped”
C1259
C1310

C1259 and C1310 are just information codes passed from the HV battery ECU to tell the other respective ECUs there is a battery problem. (This is so they can modify their behavior to further protect the car, driver and battery.)