Bad Hybrid Battery or Electric Motor?

Worrying about the electric motors is worrying about a super rare occurrence... And pack price, it's a little high for an unknown pack, but good enough. Of course you have to decide if your pack once fixed will last longer than replacement, which makes giving up your pack the gamble. The people selling to you are making an offer based on what's a good deal for them. They assume you have a good pack with one bad module and they'll recondition pack and resell... As always, the more you learn/experience you have, the lower the overall costs. Everyone should keep a spare Prius HV battery pack in their garage & just swap 'em periodically for testing... That's my philosophy... But I guess that's too much nerd for most?

 

Wow! You have a lot to learn.

First thing is to remember is these batteries can kill you.

The Gen 2 batteries has 168 cells. The cells are packed in 28 modules of 6 cells each. The dealers computer scans modules in groups of two referred to as blocks. The count starts on the side opposite the battery computer.

The dealer told you one of the modules in block 11 had a bad cell. It's the module that measured 6.7 volts. Block 11 is the two modules that are the 21st and 22nd from the side of the pack opposite the computer. They are also the 7th and 8th modules from the computer end. What you called "cell 8" is actually one module in block 11 that the dealer told you was bad.

Get a code reader! Learn how to do a forced charge and discharge!

You need to be much more careful and know more to properly repair your battery properly.

 

Since your in the Gen 2 forum I’m guessing you have a gen 2 Prius? You can’t do a straight swap between a gen 2 and gen 3 battery pack. You can change the battery modules between them.

 

any corrosion inside the battery case, or the connections?

 

Change out the bad module in block 11, and call it a day. Why did you replace a bad module with another KNOWN bad module? I don't understand the repair thought process, you're just wasting time and questioning your work afterwards.

Also a voltage reading of 7.8v means nothing, does not tell you that module is good.

If a computer is picking up that block is bad, just replace that block. If you have more skills then find the bad module in the pair. If you don't have that skill, replace the entire block

 

It seems like you still don't understand.

Again, block 11 is the the two modules that are in the 21st and 22nd position with the count starting opposite the battery computer. They are also the 7th and 8th modules counted from the battery computer. What end of the pack are you counting from? A block of two modules will not read 7.8 volts. That would be the voltage of a single module.

You did not measure the voltage of a block of two modules at 6.6 volts. You measured the voltage of one module at 6.6 volts. This module is the 21st from the end opposite the computer and the 8th module counted from the battery computer.

The 6.6 volt module (not block) is dead. It was counter productive to put that back in the pack. I'm not sure which module you replaced with the dead module.

The Gen 3 modules can be interchanged with the Gen 2 modules. Everything else is different. I would not expect a 200K Gen 3 pack to work as is if it as sat unused for any length of time. It's not a good deal if you have to give up your core. Both the Gen 3 and Gen 2 batteries have 14 blocks and 28 modules. They do not have 28 blocks (pairs of modules).

The relays and such rarely break. Be careful with the small voltage sensing wires. They are easy to break. Other than the bad battery modules the other area of concern is PEBCAK.

 

In reality he probably changed a module with no problem with the defective one, as he seems to be counting the modules from the wrong end. (He should be counting them from the end opposite the ECU.)

What he needs to do is remove the defective module he swapped in and reinstate the original one he took out.

He also really needs to take the time to understand what Strawbrad is telling him.

A picture is worth a thousand words:

 

Your best bet for reliability may be the kit of new cells sold by @2k1Toaster and listed in my signature. $1600 basically gets you a new battery pack Replacing bad modules with other used modules may extend the existing pack but it will fail again. You cannot buy new modules except in a full pack from a dealer willing to sell you the part. Many only sell the pack if they install it.

 

Actually you can balance the modules without a charger but it takes a lot of wire and a day or two. Remove all the buss bars and connect all the positive terminals together and all the negative terminals together. Then let sit for a day or two. I think it talks about it somewhere in here.

Gen II Prius Individual Battery Module Replacement | PriusChat

 

This actually doesn't do anything for the modules. Their capacities are all different, all 28 modules are completely different. Only way to properly balance them is with charge and discharge cycles, get them back to similar capacities.

 

So it doesn’t balance the voltages? That was what he was asking about.

 

The voltage reading on a module is almost a useless reading, it doesn't tell you anything. Only useful info is if you have one under 7.2v, you can throw it away. There's no other meaning to the voltage readings.

The method you described makes all the voltages look similar, until the car gets started and all will be off again. It's the capacity of the module that's more important.

 

Are you SURE you put the orange plug in correctly? I know you have taken this battery apart a bunch of times but this sounds like the the lever has not been pushed down.

$1700 is too much for a rebuilt battery. At the price you might as well get a new battery from Toyota. If you can get the car to MN I can install a rebuilt battery for $850.

 

No, it equalises the voltages, which as JC has stated is pointless.

Very confusing.

How did you drive it to the mechanic, if you can't even get it to turn on and go into gear? How is it that after driving it to the mechanic, they can't even really get it on or anything?