ReInVolt PHEV Plan

You know perfectly well i have no facts or data about reinvolt packs in nhw11 priuses, (but of your little list only the last two are actual facts, and they come straight from toyota) so congratulations, you win the internets.

 

Hmm, now I'm genuinely curious how these terms can have such nearly opposite meanings to us. I would have called the first three facts, and the last two marketing claims by Toyota.

The first three are reported facts about particular packs in Bob's and oldnoah's possession, and would (so far) need wide confidence intervals around them if extended to NHW11 and ReInvolt packs in general, just because it would take more such facts to make the C.I.s narrower.

Marketing claims have kind of a shaky status as fact until somebody independent of the marketing department reports some results. Toyota's claim about better construction and sealing has a better standing as fact thanks to Bob's reports that they really do show a markedly lower incidence of dehydration symptoms in the field--despite the small size of his sample.

Their claim about lower internal resistance is not directly confirmed by Bob's reported resistance measurements straight from the battery ECU, which seemed about the same. That's not explained yet, and because the modules are used, it could still be true that their resistance is lower when new. It could be that the modules themselves can deteriorate, or it could be that ReInvolt's way of attaching the busbars leads to higher connection resistance (the measurement inputs used by the ECU to calculate module resistance are made at the busbars and therefore include connection resistance). The explanation becomes an interesting question for further research, for which we can thank the person who took the time to report measurements.

So, even small-scale, low-budget measurements can have a useful role to play in generating further lines of inquiry from which we can learn things, and in roughly sanity-checking claims by others, be they ReInvolt or Toyota (as in, do the measurements I can get myself come out anywhere in, or completely out of, the ballpark of what's been claimed.)

More precise and confident conclusions can come from larger-scale and higher-budget measurements, sure. But hey, not everybody's got a grant.

-Chap

 

Bob,

When you install a ReInVolt pack, do you move your old battery ECU over as with a Toyota replacement, or does ReInVolt ship an ECU in the pack and get your old one back as a core?

-Chap

 

Wow .74 ohms! That means when your car is pulling 100A from the battery, say under hard acceleration, that 7.4kW worth of heat is being left in the pack. That's non-trivial! That also means there is a 74 volt drop across the pack at that time.

 

Where, if I may ask, do you get this stuff? At the end of the decade, the earliest US-spec Prius will be around twenty years old. Parts are readily available for twenty-year-old Toyotas today.

 

Apologies for the OT discourse...

FWIR automakers are only *required* to make spares available for 10 years, but since parts sales are high-profit, many do continue after this. I would not be surprised to see the parts cost rise though, as single-source parts vendors can charge whatever they want.

Case in point the $300 Toyota headlight bulb fiasco. Toyota Stealers were wanting close to a grand to install 2 new headlights in a Gen II with HID! This apparently caught the attention of some TV news programs and Toyota popped up with an apology campaign. Now they've reduced the MSRP to "only" $150 per bulb which is still robbery. Luckily Toyota is simply a reseller and not the only source so there is plenty of competition. You can easily find compatible bulbs for 90% less, and the exact same name brand for 50% less than what Toyota is asking.

Stealers make a lot of $ on parts and service, and the markup is insane! I almost wish Toyota would buy up all the dealers or at least mandate price limits. After all it's their reputation that gets tarnished from this aggressive parts pricing, not the Dealers.

So now we are approaching ten years for the Gen I and they aren't required to make replacement MG stators or battery packs. They will likely stock up a warehouse somewhere with NHW-11 parts and cease production and raise prices. I've seen NOS parts for some cars have 1000% markup. Greed and insanity! The only thing holding this in check is the salvage market, and if demand is high enough people figure out how to make or remanufacture the parts.

For instance any competent motor shop should be able to rewind a MG stator. When the cost of a new replacement approaches the labor cost of paying someone to manually rewind one, that's what will start happening.

 

As do many Tier 1 and aftermarket vendors. Competition helps keep parts prices down.

Many of the most commonly replaced parts are, and will continue to be, available from multiple sources.

Actually, your link refers to dealer parts prices on vehicles that are less than ten years old, not more.

Not all dealers are evil ogres with blood dripping from their fangs. What do you think average markup is on a dealer part? What does it cost to keep the dealership's doors open? Until we know the answers to such questions, we really can't guess how appropriate their markup is.

And if you don't like your dealer, go to another dealer. Prices vary.

That wouldn't be very efficient. Warehouses cost money to operate.

And if prices rise, it will likely be because production runs are small.

Can you name a Gen 1 part with 1000% markup?

The salvage market is but a fraction of the used part market.

Actually, the cost of a new replacement winding is already lower than the cost to rewind one. In fact, it's already about half of what it was when the Gen I was a new car.

 

All valid points. Of course I am speculating about the future, based on my experience with other cars over time. I am not quoting facts other than the HID bulb example. But regardless it seems to me that Toyota's reputation is being damaged when a loyal customer goes into a dealer for a headlight replacement and is quoted almost a thousand dollars!

If I wasn't an Engineer and capable of my own car maintenance, I would be hesitant to invest in another Toyota if I received the bills I've seen reported here for common repairs! I truly feel sorry for those people out there without the knowledge to protect themselves from these practices.

Regardless of motivation and overhead, I will likely not be convinced there is not greed involved somewhere when a dealer quotes crazy prices for simple repairs. I'm also constantly amazed at the negligence demonstrated by service departments mis-diagnosing an otherwise simple problem and turning it into a multi-thousand dollar surprise for the unsuspecting owner. This to me is unacceptable!

By the way, are you a Dealer owner or employee? =)

 

Yes, and that's a constant challenge. Although a dealership is an independent business, over which the automaker can only exert so much control, the reputation of the automaker will always rest, in part, on the dealership's perceived fairness and competence.

No. However, I have purchased parts from dealerships.

 

Thanks jk450, sorry for the off-topic discourse everyone else. Back to the original topic!

 

.432 sounds more reasonable to me, but I have no basis for that. It seems to me if there was indeed 7.4kw of heat being made, you'd have a really hot pack in no time!

In the NHW-20 the boost converter doesn't like to sustain much over 20kw, but obviously the inverter IPM's (IGBT's) can handle 50kw (MG2). Since NHW-11 doesn't have a boost converter, I would imagine the limit is much higher.

I would think that internal resistance is a function of SOC and temperature, but not necessarily (at least not directly) current. Of course current will cause heat, which will change things. The internal resistance is partly due to interconnects, the anode/cathode themselves, and the electrolyte. The first one is clearly a constant, but the electrochemical reactions in the electrodes and electrolyte aren't. As the SOC drops there are less charge carriers, so resistance goes up. Generally temperature increases the electron's motility, so I would expect a temperature rise to reduce the resistance, but there may be other factors that limit this.

 

Unfortunately I can't offer anything more than you already have. Typically they use instrumentation using high-frequency AC pulses to determine this, but I'm sure Denso does it just by watching instantaneous voltage drop in each block for a given current. Actually, they probably watch recovery when current goes to zero for a more accurate calc. There might also be some math applied to offset the effect of SOC on this calculation, but I doubt it.

Here's an interesting read. (46k PDF)

 

Toyota's diagnostic tool has a capability to report the internal resistance values.
We usually see approx 0.02 ohms/pair on the Gen2 battery.

Ken@Japan