Acceptable hybrid cell voltage

Welcome to Prius Chat .

What I would do before performing anything else is get a proper code reader as the red triangle does not always mean replace the hybrid battery .

The voltages look ok from what you posted above, the end modules typically are lower as they do not have a module on the end and each is not 1.2 volts low.

Some questions:

• How much corrosion was on the bus bars?
• What torque did you use upon reconnecting?
• Was there any signs of fluid leaks?
• How’s your mpg?
• What’s the 12 volt battery voltage?

Good luck and keep us posted .

 

You should read the codes, you probably have another problem, not the battery.

If I had to guess, it's probably a failed inverter pump. With this failure, usually the AC will not blow cold air when the red triangle is lit.

You should take this opportunity to check all your engine fluid levels too

 

I believe 48 inch/pounds is the correct torque. I don't often bother with a torque wrench, but would always use one on those nuts.

Maybe. But I've read a ton of reports of Auto Zone's readers not catching the hybrid system codes. If you're getting into battery repair, you really should get one of the mini vci dongles with techstream. Not expensive, but a little involved to install. Lots of threads here about that.

With the car in READY, remove the cap from the inverter coolant tank and look inside for motion. If the pump is running, you should see some swirling on the surface. It's not vigorous, but it's there.

 

By fluid leaks, I meant any signs of module solution leaks underneath the hv battery. This could be the early warning sign of a failed module or a leak to ground, causing the red triangle and poor performance from your Prius.

Good luck and keep us posted .

 

1) I agree you should read the codes before you waste all this time tearing things apart and throwing money at something that may not even be a problem.

2) Measuring static voltage sometimes reveals the bad cells, but sometimes it's wrong. What's more important is the difference in voltage before and after load. That is, the voltage before you loaded minus the voltage after X seconds under load. You have to measure the voltage while it's being discharged with a load at X seconds. I've had cells with good static voltage, before and after load testing that turned out to be bad when I read the voltage difference WHILE it's being discharged.

3) You don't need fancy equipment. You don't need $500 "reconditioned" cells. Buy some used cells. Load test them as described above and compare the results on those cells to the other cells in your pack. If they're similar, use them. Some of the "reconditioned" cells are nothing more than used cells that have been load tested. Even if they did some magic on them and made them super-duper cells, there's no sense in having a couple of cells that perform way better than the rest of the cells in your pack.

 

$500 for a battery that will last 6 months?
I would not do it if I planned in keeping the car longer than that.

Replacing the module yourself will save you money, but it introduces variability in the pack and is less reliable than replacing it with new.

If you replace a module you will likely be doing this same job over and over. Sometimes several times in the same year.

And every time you swap out module you add more variability to the pack. Sometimes you can mask this variability with a charge/discharge system but that adds more expense.

I'm not trying to dissuade you from replacing a single module, (I sell modules to folks regularly) but just know what you are getting into. Keep doing it as long as it is still fun for you.

 

Have you cleaned the hv battery fan?

Usually that is a sign of a failed module in the pack.

Good luck and keep us posted .

 

It is for block 5. While the freeze frame data may not show it, live data will give you a better picture of block 5.

You might have damaged the terminal or something could be causing a faulty signal reading in block 5, throwing the code.

But double checking your work in that part of the battery is warranted .

 

If it's running, it's not a parts car

 

Ultimately you get what you pay for.
Will it last a month? Sure.
A few months? Probably.
6 months? At least you'll have the warranty if it fails.
A year? Hmmm
3 years. Welll...
5 years? I doubt it

Any the entire time you can never quite trust it.
It could leave you stranded at any moment. And maybe that's ok with you.

You could buy/use tools to monitor it daily, and then you'd get a feel fro how close to failure it is, so at least you'd have some warning about when it might fail.