Gen II Prius Individual Battery Module Replacement

Sorry to disappoint you (again) - you have no idea mate.
a) Corroded sensor wires (aka voltage detective lines) can corrupt voltage readings. Even worse - corrosion goes all way up to ECU and kills ECU. For that particular reason when brand new pack is sold by Toyota - it comes with new voltage detective lines (to eliminate claims caused by corroded old ones).
b) Most negative voltage sensing wire is connected to the negative of the respective module and NOT through the ECU. And if that is corroded - you would have corrupted reading.
Play safe...and disagree respectfully or just press "like" if agree disrespectfully...

 

Roy from Canada will try to help

Here are some possible things to look for: Use rubber gloves while testing for your safety

1) Check the orange high voltage isolation plug for proper insertion- insert and raise 90 degrees.
2) It could be a low voltage 12 volt battery- boost the battery with another battery, be sure connections are correct for positive and negative.
3) Check for loose copper bars joining the modules together.
4) Measure the voltage at the point where positive and negative end cables leave the battery, it should be 220 v, have someone try to start the car - if the voltage holds at 220 volts then the battery is not the problem, if it drops down then it is either a bad bus bar connection or one bad module.

PLease post when you find the answer as it will help others in the future..

 

When you turn the leaver of the service plug 90 degrees back - you have then to slide it in position. This small step could be easily missed as not being obvious, causing one sensor (small two wire plug connected to it) to report that the plug is not there yet.

 

If you are testing the battery while the plug is in or the car is on, be very careful.
It doesn't cost more than $50 for a set of high voltage gloves.
Seeing as you are chasing down a leak/break, it is a cheap investment.

It is not worth the risk to simply use kitchen gloves etc. Use Amazon and you'll have the gloves in under a week.
You could also get leather covers for extra durability.

 

Eric is right about Elctric Gloves.
FYI: Class 0 (up to 1000V) is recommended by Toyota (Class 00 is up to 500V)
"Kitchen Gloves" are usefull to protect skin from chemicals when you are cleaning bus bars and nuts (you may use Boric Acid as recommended by Toyota) or for the "fast and furious" cleaning of the bus bars - experiment with Phosphoric Acid (at your own risk)

As for the socket set - I use insulated set - up to 1000V, see below:

 

Today I started an experiment to test what is happening to the cells within a module during rebalancing charge and discharge cycles. This was a junk module before I put the sheet metal screws in. The screws contact the cell interconnects. We can now measure individual cell voltages and capacities. The modules resting voltage is 6.60 volts. I have always rejected modules that self discharge below 7 volts. I have hundreds of junk modules to subject to testing. I am open to suggestions for tests to be done. If someone else would like to try some tests and share their results I will send them modules at no cost. If we learn anything from the junk modules I might be willing to sacrifice one or two good modules.

Brad

 

If anyone needs to get a couple of Hi Tec X4-80 Multi-Chargers that are ready to charge Prius batteries with the four sets of alligator clips needed, check out my listings on ebay. I also am selling off 8 reconditioned batteries that are solid, charging up to 7250mahr.

 

I love this thread. I have learned so much from you guys!

 

I am about to post my links to the batteries and chargers I am selling. I hope this helps someone that is in the same position as I once was.

 

Brad,

what you have observed (one cell is dead and 5 still not) - I regularly see during first few minutes of tests on my HV Analysers. Those bad modules behaviour is always the same: voltage drops abruptly during DSCH on those modules which have dead cell(s) inside. If it is CHRG cycle - it raises to above threshold levels quickly.


Was recently testing NIMH 8-cell cylinder type cell pack from specialised equipment (it did not hold the charge although have not been used much) - when dismantled - there were 2 dead cells out of 8. That pack was rearranged to 6-cell module to be used somewhere else. Then tested 6 cell pack on HV Analyser J by connecting each probe to 1.2V cell simultaneously all under one load – capacity was very good.


That condition is non-recoverable. You can’t change one dead cell in those Prius plastic modules.

You can’t revive them by cycle charge. That is why trying to rejuvenate one pack at a time without having many extra modules to choose from – is never geared for success.


Still good modules with partially lost capacity (age, mileage) are behaving differently under load down to 6V - discharge curve does not have the "steep cliff" – it is always gradual decrease during discharge or gradual increase during charge.

It is hard to see when one uses RC cycle charger and it is straight forward and visually obvious when I use my tools.

I test piles of modules at a time and visual representation and instant graphs speak for themselves and make the whole process of sorting good ones from the bad ones a breeze. In few minutes I can tell what the pack worth J $$ wise and how much capacity is left in it before delta V goes above threshold.

P.S. You can actually put those bad ones you have to a good use - Toyota requires core returns and if you have tested all of yours - you may return only non-usable ones....

 

I learned so much from you posting all this info! THANK YOU SO MUCH!

 

I really appreciate you giving us such detailed info!

 

Kiwi,
a)You took my comments out of context and thought I was saying something I did not. In post #722 blue 04 measured 10.24 volts on the battery side terminals of the relays. He then found a P3030 code and a broken sensor wire. Of course a broken sensor wire will affect the voltage readings of the ECU. A broken or corroded sensor wire will not cause the readings blue 04 measured at the relays.

b) All the voltage sensing wires have two ends. One is connected to the module and the other is connected to the ECU. The most negative sensor line is used in the ground fault detection circuit. A good description of this system can be found here. Prius battery exploration

I am a little worried about blue 04. Last we heard from him he was gloveless in a pack that was not behaving normally.

Brad


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That is a worry. Safety above all.
Alternative to gloves in some situations could be special socket set - I posted photo of the insulated socket set I've got for myself - it is up to 1000V (made in UK). Toyota also recommends insulating mat to stay on.
Today I've been playing with my portable mobile rescue chargers (powered from 12V DC SMPS @ 25-60 Amps) for Lexus/Highlander (anything with 288v nominal). With those voltages and a lots of connections/disconnections during tests gloves are mandatory...

 

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It looks like the modules towards the middle of the battery have dried out due to heat. I would try to re hydrate them by adding distilled water. This would require drilling small holes in the top of each cell, and re sealing them after adding distilled water. I would use stainless self tapping screws for this. Read Bobs post on this linked below go to post #5 for more information. You have nothing to loose trying this.

extra traction battery? | PriusChat

John (Britprius)

 

Your battery capacity is determined by the lowest module in the series string. Pairing them as you intend will fool the ECU into going to a lower overall SOC and make it more likely to reverse a cell during a deep discharge cycle. As you said, its time to find a low mileage salvaged Gen3 HV battery and "borrow" its modules.

JeffD

 

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I am about to start experimenting re-hydrating cells in low capacity modules. The modules are being kindly donated by another PC member in the UK.
I intend to start by drilling a small hole and injecting distilled water with a syringe with a fine plastic tube instead of the needle. The idea being to top up the cell then draw off any liquid above the plates after a reasonable time to allow any dried out chemical to soak up the water. The result should be similar to topping up lead acid batteries the difference being NiMh do not suffer with with the equivalent of sulphation. The reason for using a plastic filler tube is to prevent damage or shorting of any battery plates.
I will also try reducing the air pressure in the cells to remove air or gas bubbles in the same way that printer ink cartridges are refilled giving a quicker and more even fill.
This will be an extension of PC member Bob Wilson's earlier work that seemed to produced good results.

John (Britprius)

 

Cell reversal happens when the lowest charged cell in a series string voltage goes to zero and you continue to pull current from the series string. It happens one cell at a time and therefore only breaks one module. The symptom is that that module is always 1.2 volts lower than the others after charging.

JeffD