Prius Engine 4 Engine Battery?

No idea what you're talking about.

Source of what you're talking about? What do you mean by "4 battery engine"?

 

The Prototype Plug-ins had an odd battery that recharged in fourths, I think. That setup never made it to production, so I am not sure you could have replaced just 1/4 usefully. (You can replace individual cells, but balancing new with old becomes tricky)

It is fortunate that the HV Battery is very durable and we don't need to mess with it.

 

^^^
It had 3 sub-packs, not 4.

I just found a reference to the 3 packs at My visit to Toyota National Headquarters in Torrance California - And driving the Prius PHV! | PriusChat

 

That is what I was (dimly) remembering, it is not how any production Prius works.

Another possible garble, which also involves 3 batteries, is that you have an HV Battery, a 12 volt battery and a Fob battery, all of which need to work.

 

the prius has only one hybrid (motive) battery, made up of many small cells (hundreds). if it fails, you have to replace the whole thing unless you are very good at disassembling the pack, finding the bad cell, replacing it and balancing with all the others. not for your average diyer. fortunately, it warranted for 100,000 miles and 150,000 in carb states. and most last much longer.

 

OP can see Hybrid Components and Prius battery exploration about the pack on non-plugin Priuses.

 

Hi Fobber.
Current figures in USA suggest 500 batteries per month are replaced. But remember, this includes Prius models from 2000 and since there's a 100-150,000 mile warranty, a lot of these batteries are replaced for free. Generally the battery doesn't just die; there's enough warning to replace it get it checked at the next service and then decide what to do.

The battery is managed in such a way that it is never fully charged nor discharged. Depending on the model, you are using up to 80% and down to 40% of the battery capacity. Using this range means that the battery can cycle up and down for 8 years and 160,000km without loss of capacity. That's also why it is NiMH and not something more exotic.
Around the world there have been several taxis with 500,000km on the original battery. One taxi in Cairns, Australia had a pack replaced at 300,000km as a precaution and I think that this was the first battery Toyota Australia had replaced.

Toyota recycles old batteries. They don't throw the old battery into the river... upstream from an orphanage... that is run by kittens. There's a lot of value in an old battery even if there's not much spark left.
Life After Death: What Happens When Your Prius Battery Dies
http://www.autonews.com/apps/pbcs.dll/article?AID=/20120102/RETAIL07/301029980/1147

Oh, you will replace a Prius battery quite regularly: the 12 volt battery only lasts about 3 years or less in cold climates.