Project Lithium Soother Test

Hmm, I started writing this before #180 was posted ... guess I'll still ask. @mudder?

It seems two different risks have been mentioned here:

1. TMR's don't-try-this test mentions the risk of contacting the battery output terminals with the service plug removed.
2. mudder's #180 warning mentions voltage existing across the service disconnect terminals.

In a way, these aren't completely unfamiliar risks; they can also exist in any battery for which a P0AA6 is being reported. That's part of why Toyota officially says to always glove up to plug/unplug the service disconnect, even though people often don't bother. I hope people do bother if they are working on a P0AA6 code, even if they are more relaxed about it at other times.

And, of course, if the car could try to go READY with the service plug out (which P0A0D ought to prevent), then full battery voltage could appear across the service plug terminals (concern 2), because the + and − ends would be effectively joined then through the not-yet-charged inverter capacitors. And I suppose the soother does effectively connect even the far ends at all times, just through the Thévenin-equivalent impedance of a bunch of overlapping dividers.

I haven't calculated that effective impedance. I also haven't calculated the effective impedance of the path around the service plug, if you expose yourself to the voltage across the battery + and − ends (concern 1).

What I'm trying to get at is a rough idea of the current to which you could be exposed. This seems a little tricky to calculate (Thévenin-equivalents of some overlapping voltage dividers as well as whatever is contributed by the circuits surrounding and powering the opamps) and might be quicker to just measure.

Would it take long to just pull the service plug on a battery with a soother installed, then apply a few different resistances across the battery + and − ends, in series with an ammeter, and measure what current flows?

One might start with a resistance around the 100 kΩ of dry unbroken skin, and work down to lower resistances closer to 500 Ω like a wet or broken-skin path across the body. (What's the lowest resistance you'd say could be put across the battery + and − with the service plug out, without smoking the soother as in your video?)

Then we could see where those measured currents line up on a scale like this one:

 

I agree with your test method. If someone wants to safely perform it, I'll comment on their findings.

With the service disconnect plug removed, the Signal Soother's Thevenin-equivalent is essentially a 500 ohm resistor in series with a ~35 volt source (i.e. QTY10 cells in series; specifically those cells in blades 4 & 5).

For completion, there are also a couple non-linear components that I'm ignoring (i.e. the opamp's power input and the zener diode, which is essentially 0 ohms once it breaks down). These are both in parallel with a 100 nF capacitor. You can essentially ignore all three components due to how the zener diode would behave once it avalanches (at ~36 volts).

So then worst case we're looking at ~400 mA current @ 250 Vpack, which is certainly 'yikes' territory.

 

There comes a time when you are in a hole, it is best to quit digging deeper.

 

Everyone else finds it funny that that you think "lab" testing performed in a logical, repeatable manner is not valid, but all your "butt-meter testing" is irrefutable evidence.................

Of all the gizmos and "upgrades" you have on your car, how many do you think were actually developed without "lab testing"? Were they ALL actually tested on a Prius? Do you think the TB company actually installs every model of their throttle bodies on a car and dynos it or does long term testing to validate their claims? Do you think every aftermarket part is actually installed and tested on a vehicle?

 

Not sure what happened to my previous post. Did it get deleted on purpose, or was it a forum issue?
Regardless, I'll summarize it again below:

OK.
I've been quite clear why I tested on the bench, rather than in the car.

State your terms.

Because you have 1) a Gen3 Prius, and; 2) a Signal Soother.
Imagine all the points you'll get when you perform the test and nothing happens.

Sweet, let us know how it goes.

That's great. I haven't made any claims that would preclude that from happening when the pack is in good health.
You do understand what the Signal Soother does, right? If so, why have you left it installed?

State your terms.

...

Reminders:
My primary focus here is customer safety. I think we probably both agree that we want safe aftermarket lithium in our cars. I believe I have overwhelmingly shown (on the bench) that the existing NexCell products I've reviewed are unsafe, hence why I've shared that knowledge here.

As I've mentioned numerous times now, if the V3 NexCell product overcomes the numerous safety issues I've outlined, I will state that in my review. I'm not out to get Jack, per se, but I can't sit by idly as long as he continues selling unsafe products.

 

I am assuming that the moderator deleted the 3 or 4 posts that I had read earlier and are now "missing". I also assume that someone requested that they be deleted.

 

Not me. Note that it was only tmr's and my posts that were removed... so your theory doesn't make sense.
Nothing you've written 'hits home'.

 

^^^^ That's what I was thinking too - at least it wouldn't make sense for mudder to report his own post and have it deleted.

However, the last post I saw penned by AzusaPrius (that is now gone) was just a multi-paragraph ad hominem rant, so could understand if a moderator deleted it without needing a report. The post is no loss and there certainly wouldn't be any 'hitting home' or 'hurt feelings' involved.

 

blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah

 

This is some funny stuff. I'm not even aware of any of my posts being removed? How the heck would one even notice? I don't memorize how many posts I have and rarely look back through threads unless I'm searching for something specific. I couldn't care less what you post about me or to me, as they typically just make you look more foolish than anything else. I have no reason to report any posts...why bother. I have yet to see any post you've made that has been of any significance.

If there's an admin available, please feel free to post how many "report posts" requests I've ever made since becoming a member. Maybe throw a number up there for Azusa also, if he's ok with it. Let's see some facts.

 

It is true a complaint of hurt feelings may cause a moderator to delete

 

Feelings over facts. That’s how people and politicians are guided now.

 

One from me and one from ASRDogman also went away, though I see ASR has reposted his, carefully edited to convey the same wisdom in under half the original words.