I use to repair TV's for a living when I was young. I hated intermittent problems as they took much longer to find. In the electronics repair business a hair dryer and freezing cold air from a spray would sometimes show the bad part to act up and show it was bad. I would not advise that with the hybrid though.

It sure would be nice if they had a traction battery voltage readout in the instrument panel so we could keep a watch on the traction battery.

If I were you, I would learn to use the Energy monitor screen in the MFD window. Press your display button on the steering wheel till you see the combo engine/battery and wheel. The white area inside the battery indicates your traction battery charge. It will show full at 80% when it's even with the + symbol.

This would be a good comparison to the navigation monitor reading of the traction battery to see if it matched the mfd reading.

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I will keep the energy monitor display in the MFD window on from now on. A quick look at it - it seems to reflect exactly what is shown on the other display. I wonder if they get their data from the same source / input? If so, it will just reflect what I've already seen when this happens again.

Thanks,

Scott

 

Have you checked the voltage on your 12 volt battery when you first shut down, and then after it has sat overnight? The 12 volt is used for control power, and I'm wondering if it is failing, if it could affect your displays, or gas cover operation?

About 3/4 of the way down the page at the link below you will find a chart that relates voltage to battery charge. It is a long shot, but I think worth checking. You could do the same with the HV battery. However, I don't know if there is an easy and safe way to get at the main HV voltage terminals. I have checked my 12 volt but never attempted it with the HV. Others may be able to help you there.

Battery FAQ

 

I'm sure all the 245 dc volt cables are heavily insulated. The traction battery has a special high amp connector that somehow locks the cable onto the battery.

Here is a picture showing the maybe '07 Camry Hybrid battery and cabling.

49960408LUH2jpg_00000007069_zpsf673a668.jpg

 

Just a guess, both should get their battery voltage information from the ECU.

I'm wondering if you ever cycle your traction battery. This would be letting it charge to 80% then drive slow enough (25 to 30 mph) that it drains down to 20% when the engine restarts. Do this only in a safe no traffic area, best to use your flashers. Being your TCH has high miles it might be a good idea to drive it up into some nearby hills. Coming back down would give you a chance to use the brake position selection to allow the battery charge up to a full 100%. Actually it don't take but about a mile of downhill doing the brake position thing to get the 100% charge. The brake position is aimed more at a 10% to 15% downgrade.

On the discharge, I don't think I would recommend going below the 20% minimum charge. This can be done by driving the car in EV for a minute, then sliding the selector to neutral while coasting down a slight hill. Any needed braking you must put the shift lever back into Drive so the regen braking will work properly.

When I very first started driving my brand new '12 TCH. I would drive slow and the traction battery would drain all the way down to 'zero' even with the selector in drive. This went on for a week and I thought this may be why it got the increased gas mileage. After a week it would then only drain down to 20% same as the '07 TCH I had earlier. My thought toyota did this to cycle that week of driving was preparing the new battery for daily use.

Not long later a toyota tech told me the new '12 TCH had the roller rockers, variable oil and coolant pumps. No more serpentine belts to worry with. I can't remember the other few engine improvements.

 

Well, I've seen this problem twice more before hitting the 100,000 mile mark on mu 2007 Camry Hybrid. It happened at 99,200 or so miles where I saw a charge of green, all but the top bar - reflected the same level in the MFD window display - and verified the clock was OFF when I turned off the car. Parked it to go in a store, came back 20 minutes later, the hybrid battery was at 2 bars, in the purple zone, nearly completely drained. The MFD display showed the same low level as well.
Two days later the same thing happened again. Again I verified the MFD display, it matched what the computer monitor display showed both before and after, that is, when I parked the car the value was high, when I got back in it was very low. again it was perhaps 15 or 20 minutes later. I also have been stringently verifying that the dashboard clock is OFF when I turn off the car. So the car is really OFF. No lights on, no warning buzzings for open moonroof or anything like that.
Also, both times, it seems as if the battery refused to charge for several minutes of driving. It remained at the low purple 2 bar level even though the gas engine was running all the time and charging it continually. It acted as if it was continuing to drain as fast as it could charge for about 10 or 15 minutes, then finally it began to behave normally and the bars finally turned blue and began to increase.

 

Assuming it is still under warranty, I would do everything you can to document what is happening. Take photographs of the display, etc. Report it to your dealer, and get it documented. Write a letter to Toyota and describe the problem.

They may not immediately do something, but it would seem if it is really discharging that fast then something is going to happen, and you want to have the documentation to make a warranty claim based on the failure having started before the warranty expired.

 

It would be nice if you had a nearby mountain or very long hill to go down using the brakes or maybe in the Brake position which slows you to 35 to 40 mph. This way it would charge your traction battery up to the 100% mark.

I have found when this happens that top 20% is used rather fast compared to the usual 20% to 80% part of the battery.

If the battery seems to be draining intermittently a good tech can check the main supply fuses to see if it's some device in the car pulling down the traction battery.

All I can think of is the 12 volt battery is auto charged from the traction battery. The AC compressor is operated from the traction battery. Possibly the electric steering although I have not confirmed that.

The slow start recharge from 15% to 20% may indicate some problem, which may take a few miles diving before you can see it charging back up.

 

Ummm, yes it will. You simply need to configure the xgauges correctly. I borrowed one could get the voltages. In the end, ended up getting a bluetooth OBD2 reader and used torque on android which gives you individual cell voltages.

 

An update to this 2007 TCH saga.
A couple of months ago I experienced a very strange problem at about 101,000 miles with this car. I had been getting about 38 to 39 MPG regularly over the past few tankfulls of gas. One day I pulled out into traffic and immediately realized that the person in my lane was going quite a bit over the speed limit, so I had to floor it to try to accelerate to stay ahead of them. Of course, with a hybrid pressing the gas petal and accelerating are two completely different events separated by an incredible amount of computer processing, so the car sat very sluggishly for a couple of seconds before starting to move, which made me have to try to accelerate even more. This is normal behavior for a hybrid I am guessing. Finally the car "caught" and started moving and i kept the gas pressed down hard until I was up to about 50 MPH, thankfully avoiding an accident with the speeding motorist in my lane.
On the 5 mile drive home after this incident, I noticed two things: 1) my gas mileage continued to creep down and 2) my hybrid battery would not charge above the "blue" indication - around 6 bars or so.
For the following week, the car only got about 31 MPG - and the hybrid battery indicator on the nav display never went into the green. I started to be concerned, but there were no warning panel indicators anywhere. The car drove okay, but it was like the top 30% of the hybrid battery just wasn't there - the hybrid battery indicator never showed the top 3 bars charging.
Then, as mysteriously as it had started, one day about a week after this began and I was about to contact the dealer to have them look at the car, the hybrid battery started showing green again and began to fully charge and my gas mileage went back up to about 38 MPG!
I still have no idea what happened. Did my flooring the accelerator somehow cause the computer of the car to recalibrate? Did it cause one of the cells of the hybrid battery to short for a time? It all seems unlikely, especially because there were no dashboard warnings of any sort. I knew at this point that taking it to the dealer would be a waste of time, since last time I took it in they saw no scan codes and the hybrid battery had checked out fine for each individual cell. Surely if there was a battery problem, wouldn't there also be some dashboard display indication?

Now, move forward two months. Yesterday my wife took the car for a short trip to stay with a friend overnight. On the way there the car started acting odd, sluggish, and the gas mileage went down. The "service engine soon" warning came on on the dashboard display. The card had just turned over the 105,000 mile mark.
After sitting overnight (temperature low of around 45 degrees F), she got in to drive home and the dashboard lit up like a Christmas tree! She got hybrid battery failure warnings on the dash display, and the car would not accelerate properly, so she did not want to drive it home. Thankfully, she was located about 2 or 3 miles from the Toyota dealer, so she called me and I told her to bring it to the dealer, which she did.
The Toyota dealer head mechanic looked at the car and told her he had seen this problem on a TCH just last week. He said that the heater fan for the car was om high when the car was started, and that this (somehow?) causes the hybrid battery sensors to get confused and show a hybrid battery failure. He said that the car manual has a warning about making sure that you do not start the vehicle with the heater fan on high because of this issue. They went in, reset the scan codes, and charged her $95 for an hour labor (with tax). She drove the car home (about 40 miles) with no further incidence.

Okay, anyone every heard of this heater fan on high causing the hybrid battery sensors to give false readings thing? Did I miss that in the manual? What is going on here?

Thanks!