prius modules, yes or no

What is the status of the current pack?

• What are the minimum voltage module-pair numbers?
• What is the minimum voltage vs maximum voltage difference?
• Are the maximum voltage module-pairs numbers rotating?
• What are the traction battery temperatures after a typical drive?

What are your long term plans for car?

• Drive until the wheels fall off?
• Extend life 10-25 years?

What is your typical driving profile?

• Pretty much commuting car?
• Quarterly +500 mile trips?

If you plan to keep the car in service for a longish time, no thoughts of an upgrade in the next 18+ months, go for the the rebuild using Gen II or later modules. These have lower internal resistance and handle heat better than the NHW11 modules.

If it is going to be a commuter car until the wheel fall off, "carpe diem", and get a batch of NHW11 modules. Test them to establish their characteristics and keep them on the shelf with an an annual discharge/charge cycle. I'd recommend keeping four or more depending upon how good of a deal you can get.

If you are thinking about upgrading to a more modern Prius . . . how does the current pack look?

Bob Wilson

 

sounds like a good deal. for that price it's hard to go wrong. i've heard a LOT of bad things about priusrebuilders.

 

When driving, the voltage will vary but the battery controller has to measure 19 samples during these transitions. During these transitions, the voltage difference can temporarily exceed the 0.3 V threshold.

There is a probe technique that runs the traction battery voltage down and up by blocking the wheels and using "R" to discharge and "D" to let the engine recharge the traction battery. It is used to confirm a weak module BUT it is a little rough on the traction battery. It provides no hard metric on HOW weak or strong the battery, no "%" life metric.

Then it makes sense to continue driving and let the car tell you something is wrong. Your observations are close enough we don't need a video.

Bob Wilson

 

Voltage at rest is an almost useless metric. All that tells you is they might be good.

I have plenty of used Gen1 modules I can sell you that have 7.8 voltage at rest, but they have high internal resistance and low usable capacity. (i.e. they will fail if you put them in the Prius battery). How many you want to buy?

Be very careful buying used modules. Many "rebuilders" have no idea how to properly test the modules.

It's a hassle to swap modules more than once, especially if you have to pay shipping to return modules for warranty swap. (assuming the vendor will swap them).

 

Compared to what?

If you have another module or two fail with a 1.2V or higher drop . . . a cell has shorted . . . these will look brilliant. Think of them as a full-size, nearly-bald spare. Compared to the donut, it is brilliant and well capable of reaching a destination where the original tire can be repaired. <grins>

I wouldn't recommend them but they haven't failed hard and you don't have to spend any money on them.

Bob Wilson

 

I gave up on my rehydration experiments when attempts at plastic welding didn't work out. I also realized that though we might get the modules rehydrated and back to full capacity, the original problem of the leaky, terminal seals remains.

I've speculated about an alternate approach that involves drilling out the 'pressure relief' valve of two modules and connecting them with a clamped, plastic hose. The theory being small, stainless steel clamps and a heat expanded plastic tube can form a 'tight' seal over the drilled out nipples. The two modules then share a common pressure environment and the plastic tube may provide enough 'give' that the weakened seals won't leak. But this is pure speculation.

These refurbished modules have to be used together. They can never be mixed with other modules like we did with the two strong modules and two weak ones. It doesn't take long to realize it begins to look like 19-pairs, which might as well be refurbishing a full, set to 'like new capacity.'

Of course eternal glory and fame awaits anyone who makes this work . . . but I have other projects that currently have my attention. <grins>

Bob Wilson