Yet Another Hybrid Battery Replacement

The block count starts from the opposite side to the ecu

 

My last failure was in block 3 which was the sixth one from right side of the pack (ECU on left). During my previous repair last year, I shuffled the entire pack to move the inner modules to the outside edges so the block 3 failure this time is really yet another module originally in the middle.

 

My pack had two failures before 10 years and both of those happened without grid charging. AFAIK, everyone reporting here had their pack fail w/o grid charging. My third failure (another original module) has come after a year of grid charging. During that time the car only amassed about 4k miles. I'm thinking that has more to do with it.

 

It's great you're providing this data with the grid charging info. I have been curious how much longer grid charging can prolong batteries. So far it's you and JerryMildred that has come up with failures after grid charging. Not a very high number.

 

Most of the instances of where the HV battery fails under 10 years seems to be severe under-utilisation somewhere in it's life.

 

It seems to me that it would actually be more beneficial for later model Prius cars with HV battery failures, find someone to rebuild their own failed pack vs buying a rebuilt pack. Chances are you'll have a much more reliable pack by rebuilding your own failed pack.

If you get a rebuilt pack and give up your ex. 2007 pack as an exchange, you essentially could give up a 10 year old pack for a worn out 13 year old pack that will perform much worst than your own battery.

So if time permits, maybe asking to have your own pack rebuilt would get you 2 or 3 more good years vs. getting an unknown worn out pack from a 2004....that will last you a month.

 

The trick with that is the real and likely possibility that the combination of factors that caused one module to fail will have the same effect on the other modules in a similar time frame. In other words, you replace one module and another one dies soon after.

 

And my failure was almost certainly pilot error from driving right after a grid charge in FL summer heat.

 

I strongly suggest folks not doing any grid charging during summer esp in hot climates if you want to maximize your HV battery life (remember heat = bad). I always do mine in spring/winter/fall and skip doing any battery work in summer at all. Does it make a difference? Use a FLIR on your pack when you do it in summer/winter and you should be able to see what I mean.

 

Sounds like a good precaution.

 

good write-up. I have been changing out 1 module at a time with no balance of any type for about a year or more now.

You don't have to wire balance them really does nothing more than your car will do on its own

Replacing 1 bad cell at a time has resulted in 1 to 3 months of driving time before another needs replaced, usually around 3 months. I did not invest in a charge/balance machine because I'm not convinced it will help much in the long run and don't want to spend the money for it or have the time to charge/balance with only having 1 car.

The problem I have with replacing bad modules or charge/balance modules is that you never know when your battery will go bad again and go into limp mode. I just got back from vacation and 15minutes from home the Red Triangle came on and car went into limp mode with a car full of luggage and kids anxious to get home. Luckily I was close to home.

Having said that my experiences with the red triangle have been fine up until yesterday. The 4 previous times of red triangle had resulted in not much change in power and no limp mode. So car has gone into limp mode 1 time of the 4 or 5 (forget how many exactly)

 

I've been following many threads for the battery rebuild, and for the past month I've been off and on working on one of the ones on our car lot in Louisiana. After cycling all of the battery packs, then switching out the bad ones, I then leveled them over night and put them back into the car. Unfortunately I got a few codes after 5 minutes of it just running idle. I was hoping for some advice because since then I took it out and checked block 11, and 13 to see their voltages compared to the others under a load and everything seemed fine. After a couple of posts just to confirm that you 1 starts on the ECU side or opposite of the ECU side? I'll leave images attached and I really appreciate any help that can be provided.

 

On the 2nd gen, the count starts on the end opposite the ECU. The 3rd gen is the other way around.

 

This question was asked in post #41 and answered in post #42 of this thread. The block count on the Gen II starts with #1 on the opposite end from the ECU.

You need to do a proper job and do balancing charge/discharge cycles. If you envisage selling Prii on your lot and doing this regularly, you would do well to purchase a grid charger and discharger such as the HA Prolong system.

 

you made it a month, that's above average!

 

Men, you started all this spark of fire with your thread. You've really helped lots of folks over here.

Please do keep some of those skills coming.