After you take the battery out of the car you then disassemble the busbars that connects each individual small battery in the battery pack.
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With the individual cells now exposed you’ve got a whole shit load of 7.2 V nickel metal hydride batteries.
You arbitrarily pick an end and you write a number on each individual battery until you get the 34 in this case.
Then you take your digital voltmeter and grab the current voltage on each of the batteries can write it down.
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The easiest way to isolate the bad cell is to take 100 W headlight or 65 W headlight, run it on each cell for two minutes and document the voltage drop.
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after you run the headlight on the individual cell, you test again with a voltmeter and write down the voltage.
What you’ll see is that the batteries in the battery pack all are very similar in that they all drop the same amount and generally have the same starting voltage before you ran the load.
The individual cells that had more voltage dropping percentagewise than the other cells are bad.
Typically they’ll have approximately 6.5 or lower volts.
With the Toyota Camry or Prius, The batteries are rated at 7.2 V and typically have about 8 V of charge.
The biggest issue with the battery pack is getting it out without getting yourself fried… There is 1000 V capacitor that you have to verify no longer has a charge before you disconnect start disconnecting the main cables.
Oh, one other thing was that all of the bus bars were horribly corroded, which required quite a bit of work on my part to attempt to clean them because some of them were actually that bad:
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You can still see pitting in some of them were the acid didn’t quite get everything out. I literally had to take a wire brush wheel the most of these to get them mostly clean but there are pits deep enough that not at all of them will got all the way clean.
While this is a 2007 Camry it only has 77,000 miles on it. And it was wild how much corrosion was on those little busbars and the bolts.