Maintaining the health of a very old HV battery

More you drive it the better it is. Unfortunately the 2012 should also be driven. Does not sound like the battery on the 2004 is in very good health.

 

option #3: prolong battery restorer

option #4: sell one while the car market is nutz

 

I say you're already doing the most you can without getting into heroics.

The first mile or two a cold Prius drives is the hardest. If those are the only miles going on the car, that's not quite an easy life.

Enjoy it while it lasts, not much else you can do!

 

If you haven't had any warning lights, the only problem you have is lack of capacity due to a lack of battery maintenance and just by deep cycling the battery you can restore capacity back up to 96%. Maxx Volts and Hybrid Automotive sell relatively expensive products that will do this, or you can build your own for $100: Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat

As for how to use one of these system, the operation manuals on Hybrid Automotive website works well. Also to better understand the science behind Nickel-based battery and why they need regular reconditioning, go here: BU-807: How to Restore Nickel-based Batteries - Battery University

 

So you bought it for your daughter, put $3500 into it, then a year or so later she moves away, you don’t drive it and are now planning to sell it and give your daughter the first car as soon as your daughter returns and then give her your other car and buy a new one for yourself, but don’t want to sell it until then because it’s a great second car that neither your daughter nor yourselves need despite it being the best time to sell it now. Oh and the battery will need replacement soon.

 

Oh the disser who doesn't like being dissed, dissing again. You sure are opinionated but how does it lend anything to the OP's discussion. Also we don't need the rote get Dr Prius for free. So how does it feel to get dissed.

 

By you?
Insignificant

 

Batteries operate from a chemical reaction.

Over time, the chemicals "wear out" and basically disappear......or change into other forms which are not useful.

There is some debate that you can slow that process down a bit but once it is allowed to run it's natural course,
there is no way to UNdo it.

It sounds like you are very near to a final failure and when that happens, replacement is the only practical option......or sell the whole car.
It will be easier to sell if you do it while the battery is still working at least a little bit.

Thinking that there is anything you can do now to prolong it's life is just a pipe dream.
Sorry.

 

Ah the word I was looking for, regarding your Prius technical knowledge, insignificant. But not according to you.

 

It really is not the ideal second car unless it is reliable. A new set of cells may solve that issue. I agree the reconditioning strategies at a macro level are not good ones. A better half way measure is to tear it apart, clean up corrosion and replace weak cells. Then get into your maintenance driving routine. Not just for the battery but for the health of many of the systems.

 

Run 2004 out of gas
Change fluids
Park car
Remove HV and LV batteries
Jack up and set on blocks

Remove plates and insurance changing to necessary storage status

When ready the replace plates, insurance and hv
Enjoy good as new car when you need it.

 

What part of Nickel based battery science do you refuse to believe? Chemicals don't "wear out" like a machine, they change in composition to less conducting due to crystallization and can be restored by deep cycling: BU-807: How to Restore Nickel-based Batteries - Battery University

 

That battery meter bouncing from full to empty is a real warning the hybrid battery is getting ready to go I'm afraid.

2004 is a very very old Gen 2. It will make a poor car for your daughter when she returns as it will nickle and dime her to death.

Sell it.

 

That ENTIRE article talks about NiCd batteries with only one or two passing mentions of NiMh types.
Exactly which models of Prius used NiCd batteries ??
Hint: None.

 

The only way to "maintain" a very old battery is: Replace it......or don't worry about it until it becomes completely inoperative.
Any other offered options are just a waste of time.

 

I have to agree with the others who say the high voltage battery is in trouble. So your choices are: get a battery maintenance system and use it on a regular basis (could extend the life of your battery a bit, but by how much is anyone’s guess), purchase a new battery from Toyota or NewPriusBatteries, sell the car and make it someone else’s problem, or keep driving it normally and wait for the battery to fail. Either driving scenario you present will not keep the battery working long term, so there isn’t much of a difference between them.

I would recommend either getting a new battery or selling the car, since those are the only long term solutions.

 

I am in this position too with an original hv battery in my gen 2. I used to constantly worry about it's health, but I stopped worrying and follow this approach. If you're going to keep the car: drive as often as possible, stash 2k away, and do not worry about it for more than a second. Keep priuschat in the loop too!