Hybrid Battery Cell Replacement Advice

1) How were you able to reseal the module, after replacing one of the six cells that are contained w/in the module?

2) You are aware that module replacement is NOT a reliable repair? Do you have a long distance tow package? What's your time worth to you? Will your employeer allow you to not have dependable transportation? Are other people (coworkers, customers, family) dependent upon you for transportation?

3) What about internal resistance of each module? Are you trying to closely match the resistance and voltage of each module pair?

4) Are the voltage readings loaded or unloaded?

 

Welcome to Prius Chat .

Don’t forget there are more causes for the red triangle than a bad module .

Before ripping into the battery, I would get Techstream and see what the car is telling me before the blind repair / replace routine.

The voltages are not off by more than 1.2 volts, which indicates a failed cell in the module. I’d look for another cause.

Good luck and keep us posted .

 

(assuming this is a P0A80 code issue) Although you may have other semi-weak modules, #21 being at 7.09 v is effectively dead. As you said, replacing it will most likely get you up and going again. Odds are very good on that, but you certainly need to be making some longer term plans before the other ones bite you. At a minimum I would get some apps or techstream to allow convenient monitoring of the battery so you can have an accurate indication of an impending problem. Hybrid Assistant offers an app that you can perform load testing using the AC system. The battery can then be graphed by Hybrid Reporter and that makes it very easy to see modules (actually blocks) that are becoming weak.

 

kevin,

I would look at your connections in the electronics side of the battery. Sounds like maybe the (-) relay is not closing properly. You may also want to verify any plugs/fasteners you touched during the work.

 

A new OEM HV battery will give you longevity (8-10+ years), RELIABILITY, and can be moved into another Gen2, Gen3 (module swap due to incompatible cases), and possibly a Gen4.

Expensive, but amortize the cost over the likely life expectancy of 10yrs, and it's not so bad. you could also sell the pack and it would be worth more than the Frankenstein packs floating out there.

Prius could be worth zero. If it needed tires what would you do? Buy a replacement vehicle? Buy used tires? Buy new tires?

You can always get a temporary 2day subscription to Toyota TIS, to get the factory manuals and trouble shooting tree. People have been able to download and save the manual for their own reference later. Will likely require some effort on your part.

 

#2 is relevant, you just are not looking at the big picture of life/reality.

2) You are aware that module replacement is NOT a reliable repair? Do you have a long distance tow package? What's your time worth to you? Will your employeer allow you to not have dependable transportation? Are other people (coworkers, customers, family) dependent upon you for transportation?​

Many people look just look at cost, but fail to factor in reality and total cost (time is money, and there are other non-monetized costs).

Module replacement is NOT a reliable repair; count on future failures. If you are ok w/ this and prepared for it, then enjoy.

Ramification1) A future failure may occur when you are far away from home, thus the question regarding a long distance tow package. Tow companies charge a lot per mile BTW. Did you consider any of this? If yes, and you have contingencies prepared for this. Good for you.

Ramification 2) Do you have dependents/kids? I have been told daycare/afterschool care charge a lot, per minute you are late picking-up your dependents. Did you consider this? If yes, and you have contingencies prepared for this. Good for you.

Ramification 3) If your car is used for work? Frequent break downs won't be good for you, the company, the paying customer. If the car is just to get you to work, a lot of tardiness won't be good for you. Did you consider this? If yes, and you have contingencies prepared for this. Good for you.​

 

The Gen2 (2004-2009 model year) Prius HV (High Voltage) pack consists of 28 modules as you saw.

The computer monitors the HV battery in 14 blocks (pairs of modules; 28modules/2pairs-per-block = 14blocks).
A module contains six cells, enclosed in a non-serviceable package/design/container. Thus my inquiry of:

1) How were you able to reseal the module, after replacing one of the six cells that are contained w/in the module?​

You replace/swap out modules not cell(s). It is possible some talented DIY person just might be able to do a cell replacement, but have not read about such a person, yet.​

Resting (unloaded) voltage is semi-useful. A weak module will easily stick out, as you have observed yourself. A marginally weak module might show-up fine w/ your DVM; apply a load, and this same module may show-up weak. Thus the importance to test with a load.

Resistance is another factor to consider when swapping modules. Put a module with too low/high of a resistance compared to its mating pair, expect a failure very soon. Now, how does this altered pair compare to the other 13 blocks. You want all 14 blocks close in resistance. Perhaps now you can see why module replacement is NOT reliable.

Forgot about capacity. Ideally you want these close for the blocks too.

Many people don't know the complexities involved. This isn't your remote control at home where you can just swap in a healthier AA and get away with it.

 

If you're reasonable at DIY there is another alternative to replace.

 

No offense taken. You clearly have contingencies in place, good for you. Most people do NOT, and do NOT factor in the reality (not psychology) of HV failure (esp repeated failures); this is just a difference of opinion for you and I.


Factual information below that you may, or may not, find helpful:

2k1Toaster's company is a viable option for a new HV Battery (via kit), if you can NOT find a dealer to sell you the HV Battery at a price you deem reasonable.​

Techstream installation is easiest on a 32bit Windows laptop. Mac install possible, but you will have to search. You may have to return multiple miniVCI cables b/c the imitation cables lack quality control.​

Most have found the following useful:

A new OEM HV battery is pricey, but it will likely give you 8-10+years of reliability. Cheapest online price for a genuine OEM HV Battery, from an actual dealer is $1699.70; Conicelli Toyota; you would need to call and verify that they will sell to you, as not all dealers will do so. Don't forget, you should always call local dealers to see if they will beat or match the cheapest online dealer part price.

Amortize the cost over the likely life expectancy of 10years, then it might not be so expensive for you.
$1699.70/10years = $169.97/year = $14.16/month = $3.54/week = $0.51/day
Give-up 3 Starbucks latte a month, for the next 10years, you just paid for this HV Battery.

The car could be worth $zero. But, the HV Battery gives you flexibility b/c it can be transferred into a younger/lower mileage Gen2 (2004-2009), or into a Gen3 (2010-2015) via module swap into the Gen3 HV Battery case, and possibly into a Gen4 (module swap due to different HV Battery case). Also, you could sell the OEM HV Battery, recovering a fair amount of your expense, if a cost prohibitive auto accident or future repair bill occurs.

A used/rebuilt/remanufactured/reconditioned HV Battery is NOT a reliable repair. Very few good "rebuilds" exist b/c the Gen2 modules are 9-14 years, old and getting older.​

 

Hmm. I'd say something not right.

I have Version 8, and it took maybe 8-10 minutes? I wasn't timing, but I could see slow steady progress. 45min, I would have gone crazy.

Maybe uninstall and reinstall the software? Maybe install an older version: 8,9,10,11,12?

 

All these versions of Techstream are gray market. Basically they're illegal and hacked and usually contain all sorts of spyware and trojans. Knowing this you can sandbox it. Don't install it on anything that connects to your home network EVER.I see the network connected icon in your screenshot...

And because they're hacked, they have some screwy behaviour some of the time. 45 minutes is too long. But I have seen 10-15 minutes before depending on the scanner. It usually takes 2 minutes on my Prius with my scanner.

Also they mostly enjoy running in XP x86. So a VM running XP x86 ontop of whatever you want with the network adapters disconnected is the best and safest way of doing things.