Replacing two bad cells in battery pack, 2004 prius, 207,000 miles

The reality is the pack in your 2004 is not going to last much longer regardless of what you do. Your "quick fix" might last a year but that's very unlikely. If you do decide to do it right it's going to cost you $500 at least for the replacement modules and the pack charger. It would take too long to recondition the pack with the Reaktor,

If you plan on keeping the car for a few years you should just go ahead and buy a brand new pack from Toyota. You can order one online from Szott M59 Toyota in Waterford for about $2000 and pick it up there. You will need to swap parts from your old pack into the new one. That is your best bet IMHO.

 

yes, rebuilds are unreliable. but some last longer than others. no way of knowing.

the good part about a new battery isn't the warranty, it's the fact that they almost always last well over 100,000 miles.
as for prolong, great product, but, better for older working batteries than one's that have failed. pm the owner @jeff652 for an opinion on your situation.

 

As long as you replaced the failed modules BEFORE you installed and used the prolong charger you might end up with a pack that will last a while. But you won't unless you complete the discharge/charge cycles that Hybrid Automotive recommends. Using the charger alone will not rejuvenate your old, tired battery pack.

A new pack will outlast any rebuilt pack by 3 times or more. Don't worry about the warranty. Toyota wants its stealerships to succeed so that's why their warranty is triple that of a DIY install.

It's not so much the reliability of the rebuilt packs it's who did the rebuilding. You will learn this as you gain more knowledge and experience.

I wished you would have taken my advice and bought new; nevertheless, I hope you're able to repair your pack and get your money's worth out of what you've bought so far.

 

Thanks for your order . Charging and balancing alone will not deliver long lasting results. To get the most benefit from reconditioning, you need to cycle the cells over a much wider range than the car normally allows. It's the discharge sub-cycle specifically that breaks down the voltage depression memory effect and restores lost capacity. Charging alone is only half of the solution

For a DIY consumer, it's worth reconditioning the pack before replacing any modules. About 50% of the time, that''s enough to recover the pack and keep the car going. If the battery still exhibits trouble after the first reconditioning treatment, it's time to load test the modules and replace the bad ones. After replacing, recondition again so the new & old modules can normalize to each other. For a shop/rebuilder who wants to minimize the risk of a warranty claim, going straight to load testing and replacing weak modules makes the most sense. But, yeah, charging alone will not last for the long term.

 

Come on, Jeff. If each of the two modules failed in the OP's pack due to an internal short in one of the six cells then trying to recondition is likely to make other modules fail because the bad ones will overheat and potentially blow their lids.

Not a good idea to recommend to an owner with known bad modules to use your product before replacing them.

 

Kevin, mine failed but I repaired it and have been charging/discharging it with the prolong solution. More info on that here: My P0A080 fault code and battery rebuild | PriusChat

GOOD LUCK!

 

If the OP has already determined he has two failed modules, then they should be replaced. I was speaking broadly in my response. To assume that every battery red triangle event is due to a hard cell failure (such as high IR or internal short) and to assume every battery red triangle event will require module replacement is not correct. Based on our customer feedback somewhere between 1/3 and 1/2 of the time reconditioning alone is enough. This is why we recommend reconditioning first, before tearing down to the module level and load testing/replacing. Often it's simply not needed.

I experienced this on my own 2005 Prius. It "failed" almost three years ago with a battery red triangle, loss of power limp-mode stranded on side of road event. I reconditioned the pack as-is and was back on the road without touching the modules. It's been almost three years and the car is still going strong and I have never replaced any of the pack, only maintained it at regular intervals. If the OP has already done testing and determined he has failed modules that can't be cycled and restored, then I agree he should replace them.

 

Yes, absolutely. Our online store is here:
Online Store - Hybrid Automotive

Here is the Prius light bulb discharger:
Prolong™ Simple Discharger - Hybrid Automotive

 

This is new information that should have been disclosed in the first post. Imagine driving for months on an engine showing a critically low oil level and then expecting that adding some new oil now will make it better again.

 

Did you press the Start button twice? It must be pressed twice to enter Ready Mode the first time after reconnecting the 12V aux battery.