I blew up the inverter????

I would doubt the accuracy of your gauge.

From About.com

Bosch electronic regulators are set to 14.2V, this I know from many years working as a mechanic. If an alternator was charging as high as 14.6 volts I would replace the regulator to avoid battery damage. Of course this is the voltage across the battery not across an open circuit alternator.
My tests were using either a Fluke Meter or a engine diagnostic centre like a Vane 770 or a SnapOn computer based diagnostic center.

This is from Training Manual
I think Prestolite know a thing or 2 about alternators.

 

Your picture is a bit fuzzy, but if this is intended to show voltage produced by a Prius when READY, then I question the accuracy of your meter - I believe it is overstating the true voltage.

What voltage does your meter show after the car has been IG-OFF for a couple of hours? If your battery is in good condition and the meter reads more than 12.6V-12.8V, then this is further evidence that your meter is inaccurate.

See the following Wikipedia link that indicates the following:
Open-circuit (quiescent) at full charge: 12.6 V to 12.8 V (2.10-2.13V per cell)
Continuous-preservation (float) charging: 13.4 V for gelled electrolyte; 13.5 V for AGM (absorbed glass mat) and 13.8 V for flooded cells
After full charge the terminal voltage will drop quickly to 13.2 V and then slowly to 12.6 V.

Lead-acid battery - Wikipedia, the free encyclopedia

I have two Fluke DMMs and have used them to measure the voltage produced by the three Toyota hybrids that I have owned. All produce around 13.8V.

 

That sounds like a good plan. Now I'd already done a good deal of 12VDC testing before:

Prius - UPS Project
​

That data showed a voltage range of 13.75-13.94 VDC at current ranges from 1.1-74 A. But it may be my 2003 Prius is unique and I welcome any excuse to play with our cars.

I just started my wife's Echo and measured 13.88 VDC using a Micronta DVM. I also tried to measure her battery voltage with a $5 cheap DVM bought at Harbor Freight and it never returned a steady voltage while the engine was running but kept following the noise on the battery terminals.

Your photo is a little out of focus. Is that a Vector VEC008 Digital LCD Voltmeter? I sure hope it has better performance than the $5 cheap DVM bought at Harbor Freight.

Bob Wilson

ps. I built a simple microprocessor temperature recorder only to discover the 12-bit, analog-to-digital converter reported unexpected 'noise' using the on-chip thermistor. The only way to get usable data was to apply a seven element, Gaussian filter.

 

Hi Bob,

That looks like a good ID.

Hi problemchild,

If you are interested in accurate measurements, may I suggest that you buy a real digital multimeter, spend $100 or so. I note that this Vector meter is priced at $15 list; you probably cannot expect a cheap meter to accurately measure DC voltage when an AC component is also present, not to mention all the RF noise produced by the Prius electronics.

 

I had one of these same meters, designed to plug into the lighter socket. I used in my VW Westfalia to monitor the battery while camping. It was notoriously inaccurate! The voltage was as much as 1.0 volts off compared to my Fluke. It also had no consistency as to how it was off, sometimes high, sometimes low. Looked cool but useless!

Icarus

 

FYI: For everyone: My scan gauge tells me that my "12volt" battery voltage is straight up 14.0 while driving with a fully charged battery and the lights, radio and heater on.

Icarus

PS I realize this is a parallel post from the how to charge a 12 volt battery thread,,,

 

Since we've been discussing what should be expected regarding 12V auxiliary battery voltage with Prius and other vehicles, I decided to measure the voltages on my three vehicles today. Here are the results per my Fluke Model 87 DMM:

Vehicle IG-OFF IG-ON (not READY) READY
2004 Prius 12.73V 12.03V 13.91V
2006 HiHy 4WD-i 12.13V 11.83V 13.94V
2000 Ford Mustang GT 12.19V 11.79V 14.44V

The IG-OFF voltage on the Prius shows the battery is fully charged which is not surprising since that car is driven the most. The batteries on the other vehicles are partially discharged due to their relative lower usage.

The Fluke measured around 13 mV AC ripple on the Prius when READY, which is good. It also showed that the frequency of the ripple ranges from 460 - 510 Hz. The waveform duty cycle is 57 - 66% (compared to a pure sine wave that measures 50%.)

For comparison, the HiHy showed the same amount of ripple, the frequency was 417 - 430 Hz, and the waveform duty cycle was 15 - 18% (so the waveform is probably some kind of sawtooth.)

The Mustang, being of traditional design, has a higher voltage when the engine is running. The AC ripple showed changes in frequency as engine RPM increased, but interestingly the frequency did not double as the RPM doubled. For example, it was around 200 Hz at 800 RPM idle speed but only around 400 Hz at 3,000 RPM. Not sure why this is the case - maybe there is noise in the signal.

I have an HP two-channel oscilloscope, but at this time am not motivated to drag it out to the garage...

 

Not sure if this was mentioned earlier, but batteries have something called a surface charge which can read a bit higher that normal shortly after taken off of a charger. So, a typical 12v lead acid may read 12.6 or so right after the car is shut down. After putting a load on it for a short time it should return to it's normal state of 12.0

My Prius charging voltage varies between 13.9 and 14.0 according to the scangauge I have. The factory service manual lists charging voltage with ready light on at 14 volts, ready light off at 12 volts. Not really that precise but pretty close to the scangauge data.

 

Sorry, but your are wrong. a 12 volt battery at 12 volts is a "dead" 12 volt battery. A normal flooded lead acid battery fully charge should be ~ 12.7-12.7vdc.

I suggest that everyone read the following:Car and Deep Cycle Battery FAQ

Or : http://www.batteryfaq.org/

Or : Deep Cycle Battery FAQ

Icarus

 

Sorry, but your are wrong. a 12 volt battery at 12 volts is a "dead" 12 volt battery. A normal flooded lead acid battery fully charge should be ~ 12.6-12.7vdc.

You are right however about surface charge, that could be in excess of 13vdc.

I suggest that everyone read the following:Car and Deep Cycle Battery FAQ

Or : http://www.batteryfaq.org/

Or : Deep Cycle Battery FAQ

Icarus

 

Our boat has a large deep-cycle 12V lead-acid gel cell battery which is used for house power and engine starting. Being large and expensive, and used for deep cycles, we try to give it every advantage by using a smart charging system, both for shore power charging and alternator charging. Our charger is programmed for the batteries characteristics and monitors current, voltage, and battery temperature, providing an optimized charging profile. The charging process is broken into three stages:

1) Bulk. In this stage charging is limited by the capacity of the charger and the temperature of the battery. Ours is a 100 Amp charger, so in this stage it shoves 100 Amps continuously into the battery. The voltage a the battery rises to around 14.4 V during bulk charging.

2) Acceptance. As the surface of the battery plates charge, the current has to penetrate into the plates to continue charging. This causes the battery voltage to rise. Once the voltage has reached its maximum safe level, the charger starts backing off the current to keep the voltage at the safe level. This is about 14.4 V for our battery. During the acceptance phase the voltage remains constant and the current tapers off as the plates become more deeply charged.

3) Float. Eventually the tapering current becomes asymptotic, at which point it has reached the level of diminished returns. When this threshold is reached, the charger stops regulating current and holds the battery at a fixed "float" voltage. For our battery this is 13.8 V. This voltage is maintained anytime the battery is charged and power is being supplied by the charger or alternator.

If we had a flooded plate battery, we would occasionally run an "equalization" cycle, where the battery would be charged at a higher voltage to reduce sulfation. The sealed gel cell battery that we have does not benefit from equalization.

We never run our battery down past the 50% point. The voltage as the 50% point is about 12.8 V. Just as with the Prius, keeping the battery above a minimum level of charge greatly increases battery life. Our current battery has been happily powering our boat for a decade. Being nice to batteries pays in the long run.

Tom

 

In the solar world, we try to keep the discharge rates such that the battery almost never drops below 80%, with the occasional 50% being acceptable.

If you read the above battery links about "cycles" you will realize that the life of batteries depends on the depth of discharge and the number of cycles.

Icarus

 

If the OP is still around, and you decide to go ahead with repairs you may want to talk to Steve at:
04 and newer Prius Parts Cars

He's rebuilding 2004+ inverters now, looks from his website like you can get a rebuilt one for $895 with exchange. You'd still need someone to pull it and reinstall though. and you'd want to be confident that a) you really need an inverter and b) there is nothing else wrong. You might still have to have the work done at the dealer, but should save you quite a bit.

BTW, what are the specs on your charger? If you usually use it to charge an RV I'd be a little worried that its way over sized for the Prius?

Rob

 

Here is what happened to Ginny's car. (and the four others at the dealership with the same problem)

1. The car was brought to the dealer.
2. Service tech tried to start it and it would not start.
3. Told the new kid with the summer job at the service department to try and jump the Prius.
4. New kid reverses polarity when trying to jump the car.
5. New kid tells service tech that the car still won't start.
6. Service tech determines that the customer must have reversed polartity when trying to jump Prius.
7. Service writer calls customer to get authorization for $4800 repair.
8. This same kid destroys the inverters on three more Prii' while the service writers go on to joke about all of the stupid Prius owners who keep frying their Inverters!

 

WHAT!!!! Man that has got to be one expensive 'summer job' employee!!!!

Was this written up in the paper or something ... via the grapevine?

WOW!!! :blink::blink:

Bob Wilson

 

Did you mean Fuse rather than defuser?
The fusable links on most cars are usually located as near the battery as possible to provide isolation in the event of an accident.

If you jumped the car from under the hood the dead battery would have had to draw 100 amps to open the fuse, whether reversed or not.

I would get a wiring diagram and find the location of the fusable links. If they are near the battery then I'd suggest to dealer he blew the inverter when he attempted to jump from battery.

I'm real surprised that power circuit doesn't have a crowbar rectifier in circuit to protect from reverse voltage.

I'm still learning about hybrids but why would Low voltage 12vdc battery be connected to inverter with large fuse? 12vdc battery is for powering control electronics and start motor.

 

Proof?

Also, not wishing in the slightest to make light of this situation because I am certain it is incredibly frustrating, but the thread title should be changed to "Honey, I blew up the inverter".

 

Hi Patrick,

Well, yeah. But the inverter is runing at what 20 KHz? That takes a tiny capacitor and inductor to filter.

The engine driven alternator on the Jump Starter probably has 400 Hz ripple on it. Without the battery, the available filter caps in the car might not provide much ripple reduction.

 

My guess is that Winston was trying to be funny...

 

I'm not sure - I thought the inverter was running at 5 kHz. What is interesting is that the Fluke DMM shows the ripple around 400 - 500 Hz; perhaps there are multiple signals present that an oscilloscope would display.