my 01 prius is weird but good

Crazy is right! 70-80 mpg on the highway? Something doesn't sound right. Hopfully all goes well for you, good luck in diagnosing the battery issue.

 

So you are rolling around on two or four donut spares or smaller diameter tires? That would provide indicated or similar performance metrics if not corrected for actual tire size. Being lower to the ground would also reduce drag.

Bob Wilson

 

<div class='quotetop'>QUOTE(statultra @ Aug 22 2007, 04:29 PM) [snapback]500555[/snapback]</div>

The voltage between contacts would be about 2.4 volts. This is way too low for arcing across contacts. However, corrosion on the contacts could raise the contact resistance causing heating of the contact. However, that would be localized heating.

The battery is not disconnected anytime the "ready" indication is on, but charging and disharging are limited based on battery temperature. I do not know the specifics.

 

I would also be concerned by the HV battery case feeling hot. If you are up for it, please dismount the battery, open the case, and safely inspect the interconnects for corrosion.

If all sensors are performing correctly, charge and discharge of the HV battery are reduced at both temperature extremes.

One possible benign explanation of both the temperature and high fan speed is that the battery ventilation system is physically blocked in some way.

 

The controler under the bonnet must be doing something strange. If the battery had high resistance you would have poor acceleration and the battery wouldn't get hot but the high resistance connector would.
If the controler was putting too much power to the motors and allowing too fast charging that might explain the problem.
Have it sorted, it will kill your battery.

 

As a general rule, one tends not to look a 'gift horse in the mouth.' However, assuming the vehicle appears to be ordinary, there is a radical thought. Has the transaxle oil leaked out?

There was one report of a New Jersey Prius that had lost all or most of the transaxle oil. The owner claimed they went 20,000 miles and then drained and replaced the oil. The lower half of the differential gears are in the oil bath and the oil provides some viscosity losses. Since this is a 'salvage' vehicle, there may be merit in checking the oil level at the transaxle filler port.

It would be interesting to see the fill-up mileage. It is possible this vehicle is failing in someway that causes excessive battery usage in some modes only to be replaced by higher battery charging loads at other times. If the total mileage measured at the pump remains the same, then it would make sense. Due to guage inaccuracies, the fuel recepts and trip-meter mileage is a better indication.

Bob Wilson

 

Just another thought. With the Toyota charger, the Battery ECU is also connected to monitor the SOC during charging. The HV Battery is also not fully charged, just about 40~50% so that it is enough to start MG1 and then ICE to take over the charging process.

For your case, you have charged the HV Battery offline so the Battery ECU wasn't aware that the actual SOC has changed. Although the Battery ECU still thinks the SOC is low (SOC kept in it's memory), but with the higher voltages and amperage after your offline charging, MG1 can still be controlled to start ICE. Once ICE started, the Battery ECU will request HV ECU to keep charging the HV Battery until its SOC in memory reaches the target SOC of about 60%. But since your actual SOC is much higher than the SOC in memory, the HV Battery may have been overcharged pass the 80% upper limit. This overcharging will generate a lot of heat so the blower has to be turned on at HIGH speed to try to cool down the HV Battery. At the same time, the Battery ECU may inhibit further charging due to the high Battery temperature until its temperature drops to the chargeable temperature. Once it has dropped to the chargeable temperature, the SOC in memory may have fallen below the lower limit and the charging cycle will repeat itself so your HV Battery is always at high temperature.

If the above is what I think is happening, my advice is to bring it to the dealer asap. Overcharging not only shorten its life, worst still it may catch fire!

 

Just to clarify... are you charging the aux battery or the "traction" battery?

Just a random thought, no idea if it will work as I think it will but: You might want to "reset" the computer's settings by disconnecting the aux battery... hopefully it can reset the battery ECU?