2001 Battery Question

Welcome!

Sounds like those are in good shape. My battery is fine and shows .1 volt difference between the highest and lowest modules. Yours shows .01 difference. Can I have your battery?

I don't think you need to do a load test because the voltage is so even. These batteries have a much more robust chemistry than lead acid and the Prius "babies" them. They will wake up nicely after a long time dormant if they have not been discharged too far.

Is there any corrosion on the terminals? That's something you should take care of before you put it in. Common problem on the gen 1 in hot or hilly country.

It will be interesting to see how bad the original pack is since you are still able to drive it. Is it throwing codes?

Check a couple of terminals and pop that baby in there. That's my two cents.

 

There is growing evidence that the electrolyte leak from terminals in the NHW11 modules can cause a P3009 code even though the modules still have service life. You may be able to clean the corrosion but more importantly, the electrolyte seepage to the case and restore the pack to service.

I would still keep the salvage pack and take time to refurbish it ... clean modules and terminals. You might contact "Re-InVolt" and look at their product offerings. Replacing the NHW11 modules with NHW20 modules would give you an excellent replacement battery.

Bob Wilson

 

Most dealers don't go past the codes when they do a check. "Code p3009? Oh dear. You need a new battery. $3009 please." There is a TSB out to clean and reseal the terminals for free if a customer asks but if the customer does not know then the dealer will just say you need a new battery. The voltage leak code P3009 Bob mentioned may point to that. I seem to think that this TSB can be asked for at any time even past warranty but I could be wrong on that.

It seems strange that you don't get a code on the scanguage though. Does the check engine light stay on while in ready mode?

 

If a traction battery ECU DTC was logged, the ScanGauge is not going to pick that up. If you're lucky, that device will report engine ECU DTCs.

It sounds like the OP has a good salvage battery, once the corrosion is cleaned off.

OP's post #3 says that a PS warning has appeared. I assume that is on the MFD?

That means that the electric power steering has a problem (the Classic Prius electric steering gear is a known fault area), so the vehicle may have more than one issue. Does the steering wheel shake while the car is being driven?

 

Mine has the same PS symbol every time the warning lights come on (like when 'im doing "experiments") but my PS is fine and I never get a code.

I think that it's just a generic warning screen. Are the symbols greybatt, greyPS, red car! That's what I get any time it goes off which is only when I make it.

But if it shakes...that's the "wiper" issue , right Patrick?

 

Yes. The variable resistors within the electric steering gear are dirty, so that confuses the steering ECU and results in steering wheel shaking.

 

That's a good voltage. I just went out and checked the Graham scanner and I get 282V and an SOC of 52%

What do the blocks read?

 

.2V max difference. Hmm. That does not sound that bad but let's see what the experts have to say.

I'll be doing this at some point too so It's good to know.

There is a cell balancing procedure that the dealer can do. It's in a TSB meant for when the cars arrive but I don't see why they can't do it for us now. It takes about 30 minutes plus set up time. I'd do it myself but you need the special Toyota service computer to do it.

 

My min/max is 15.24 15.45.

2.1V diff.

Should I be worried?

 

The diff is 0.21V. Hey, if the car works, then don't worry.

 

The total voltage sounds OK, as well as the module pair voltage you measured. I assume that the reason the traction battery ECU logged a DTC in your case is due to the leakage and corrosion, causing DTC P3009. If you see electrolyte touching the metal battery case, then there would be a high voltage leak for sure.

 

It probably would be a good idea to force charge the traction battery by making the Prius READY, shifting to D, pressing hard on the brake pedal with your left foot, then flooring the accelerator pedal with your right foot. Since you are holding the car stationary with the brake, all engine power is diverted into MG1 which causes the traction battery to charge. Suggest that you stop once the traction battery gauge shows 75%.

Then, see if you still have warning lights appear. If not, take the car for a drive (30-40 miles) and see what happens.

If you continue to get the PS warning icon, try turning the steering wheel full counterclockwise, then full clockwise, a few times - in an attempt to clean the torque sensor potentiometers. That might give temporary relief.