Need Advice / Recommendations for Hybrid Battery Replacement - What is the best option?

If the car has been sitting for a year, you may not need to do much except a new 12v battery and possibly the HV battery (make sure it hasn't been changed). With gen2 cars from 2004-2009, many already have replacement HV batteries in them. Change the oil, check the tires/brakes and go for a drive. I wouldn't invest heavily into this car unless you've put at least 1000 reliable miles on it.

 

That's a nice list. Somewhere along the line you want to inspect the brakes, change the brake fluid, change (drain an refill) the transmission fluid, clean the throttle body (TB) and mass airflow sensor (MAF). PCV valve and hose. Check the condition of the water pump belt and cooling hoses. Plan to replace the inverter coolant pump and the "three way valve" (for the Coolant Heat Storage tank) in the near future as both are common faults.

Siphoning gas out of a Gen2 prius is almost impossible. It's about 4-1/2 feet from the gas cap to the actual fuel bladder in the tank- with several sharp bends, a step down in fill pipe diameter, and a one-way flapper valve to force open. Another option would be to safely raise and support the car, and disconnect the fuel pressure line at the right front corner of the tank. Connect an adapter (from a fuel pressure gauge set) and hose to the line fitting from the tank to go to a waste gas container. Then either use a scantool to command the pump on or remove the back seat bottom to access and jumper power to the pump connector at the tank.

Might suggest you first replace the 12V, clean TB and MAF, check fluids and see what you have. Operate the 12V systems and see what functions. Connect a Prius compatible scantool and see what the systems report. See if the HV battery is dead or not before attempting to "ready" the car. You might (will) need a HV battery, but might want to find out as much as possible before spending $$$. (Would stink to put in a bunch of work and a new HV battery only to find that the brake accumulator assembly is bad or some such thing).

A new Toyota HV battery (if correctly installed) should be fine for 10 years. You will want to understand Toyota's core return policy as I have read somewhere that they might reject the old battery under some circumstances. Another option is Newpriusbatteries.com. Be sure to fully read and follow installation instructions to the letter- esp torquing fasteners to spec.

Before beginning you will want to get a copy of the factory service manual, as well as (use of) a capable scantool (snap on, some models of autel, or Techstream). Also consider getting a Bluetooth OBD2 adapter that will work with apps such as Dr Prius and Hybrid Assistant- both specifically monitor HV battery info (great to have "on the go" in your glove box).

Once everything is up and going, there's the usual stuff on an older Gen2- tires, TPMS sensors, slow tire leaks due to rim corrosion, possible water leaks around the rear hatch, etc.

Posted via the PriusChat mobile app.

 

Maybe being a new member is causing a problem ????
When you look at a message that he posted, is there NOT a "reply" box/button in the lower right corner of the screen ?

The system may append an @ in some places but YOU should not.

 

https://projectlithium.com/products/prius-lithium-replacement-pack

has them back in stock it looks like but for the same price as OEM then going with OEM would be the best choice if you end up needing a new one

 

If the OP needs a copy of the Gen2 Maintenance Manual, he cam PM me and I will send him a link to the manual on my Web server. There are two versions; one for the 2004-2005 Gen2, and the other covers 2006-2009 Gen2. There are minor differences.

JeffD

 

would it be downloable as a pdf i assume? if so would you mind if i got the 2006 manual?

 

I don't think PMs can be sent on here, that seemed to have been disabled.

Maybe just list your email and the professor will email you a copy

 

Nancy,

I posted the link to the manual on your profile page. It is a large zip file containing many pdfs.

JeffD

 

Just click the link on Nancy's page

 

There are three issues with your HV:

• is there any charge left in it
• is it out of balance
• is it bad.

Most NIMH batteries will have discharged to basically nothing if left unattended for a year. You will not be able to start the car with a dead HV battery and you do not want to try to start it with one which is nearly dead and out of balance, as it will reverse polarize some of the cells and damage them. There is one upside to a fully discharged battery - it is also fully balanced (all cells at the same state of charge).

So at the very least you will need to find some way to charge the HV battery. The dealer can do that for you, but it will probably be expensive. You could buy a Prolong charger, but for $600 (something like that, last time I looked) that is a very significant fraction of the cost of a replacement HV battery. There may be a hybrid shop near you which would do this for not too much? If you want to do it yourself, open the battery case (safety switch first!), then you could pretty rapidly get it charged enough to start the car by putting 2A or so into each module for exactly the same amount of time. A current limiting power supply would be used, but be sure that it is one which is stable in this application. (The BioRad model 200 power supply, for instance, was unstable when charging a Honda Civic Hybrid pack at 300mA until I added a drop resistor in series. It was designed for a purely resistive load and packs of serial NIMH batteries are not that.) Charge all of the modules to say 30%. Just enough to run diagnostics on the battery, and possibly to start the car. I don't recall what the ratings are for these cells so cannot tell you how many minutes that would be. If your power supply does not go to a high enough voltage to do the whole pack then clamp it around however many modules in sequence in the pack it can handle. In any case, for a short charge like that from fully depleted you don't need to worry about any cells hitting fully charged, at which point the current would have to be limited to ~300mA (a guess) so that the slower cells can catch up without damaging the fully charged cells. If some of the cells are already bad 2A may be too much for them, but in that case you need a new pack anyway.

 

I posted it on TPs page anyway (Nancy's page only had the 2006-2009 manual).

JeffD

 

The OEM Toyota battery at $2300 installed is a bargain if you compare it with a replacement at $38111.74 for a Ford Mustang Mach-e traction battery! That is 38k not a typo!
HV Battery Replacement Cost | Ford Mustang Mach-E Forum - MachEforum.com

 

You would take off the HV battery cover to see if the modules have sequential serial numbers. You might consider reconditioning the battery by using a grid charger and discharger.

Since the HV battery fan is nearby, check for build up, then clean if needed. With the rear plastic removed, you can also look for leaks.

Be sure you buy a quality product : Hybrid battery diagnostic and repair tool for Toyota and Lexus

Many like to use a mini-vci cable (or better) and techstream (dealer technician diagnostic software) installed on a windows device.