Replacing hybrid battery with new OEM - transfer new cells to old batt?

My 2005 Prius battery is pretty much dead. I've spent $50 or so just replacing individual cells every few months but it keeps going out. I've decided to purchase a new OEM battery from a local dealer. I read that it doesn't come with the ECU or anything attached.

Does anyone know if it's easier to just transfer the new cells to my existing battery housing, rather than transferring the ECU/relays to the new housing? I've replaced cells a few times now so I'm pretty comfortable with that process - but there aren't really any YouTube videos on how to transfer the ECU to a new OEM battery.

 

Thanks for that info. If it's easier than replacing modules then I would feel pretty confident. Even a local independent shop was quoting $650 for labor, so I figured I might as well do it myself if I've already done it before.

Will report back once I do.

 

Not sure where you read that I had no understanding. I'm sure I could probably do it, I'm just hesitant of working on my only car without having any tutorials/documentation on hand in case I get stuck or do something wrong.

I've been doing it so frequently because I've just been replacing the modules from whichever block looks dead in Dr. Prius. Haven't been rebalancing the pack or anything because it's 17 years old and I'd rather just replace the whole thing with an OEM battery now to give it another 15 years of life.

Just followed this video the first time but now I follow this one as he shows how to remove the battery without having to remove side trim.

Perhaps I was asking a stupid question originally, but it seems like I got my answer: that it should be pretty straightforward to just swap the electronics. Thanks all!

 

Update - got a new battery from the dealer for $1950 (after core return). Called 3 dealers near me and all had the same price.

The install was indeed straightforward. Three 10mm bolts attaching the electronic stuff to the battery chassis, and then of course unplugging and reconnecting everything.

The battery wasn't fully assembled, it had a few wires in a separate bag. I put them in place but didn't actually connect them to the battery until I was done transferring the electronics, for safety.

Honestly, the hardest part was opening up the huge crate.



The difference in acceleration was immediately noticeable, even compared to when I first got the car and it had no battery issues. Brakes are also way more responsive, interestingly.

Definitely glad I spent the extra few $$$ for a new OEM. Should outlive everything else on the car now.

 

IMO it was easy. Nothing is really that complex, just takes some time to transfer everything, and it's a bit hard to work in the small space. Make sure to take a bunch of pictures for reference before you start disassembling the old one!

Battery's still good, haven't had any issues since replacing. $1635 is a great deal; I'm jealous. Good luck, you should have no problems!