Death by 9V battery design challenge

I really hate to design stuff that will get heavy regulatory review. Medical, flight hardware, things like that. 90% of the work becomes the regulatory overhad.

Electric motors (and batteries) can be grossly over-driven in short spurts, until they overheat, so a Tesla can have grotesque acceleration in short bursts. They can rate the motor for its peak output.

I guess there's almost no limit to how hard you can push an induction motor for 10 seconds. 10x steady-state for sure.

Don't let Homeland Security find out!

Well said, mate. I'm sure he hasn't the brains to realize that 'make your own taser' features on dozens of YT videos - and go look there for the details instead. ;->

Maybe you weren't dead long enough IYKWIM. That'd be my guess. They say it can change your entire perspective on life. Fascinating IMO, but a lot of folks reckon it's just halucinations caused by oxygen deprevation. I demur.

The LEAF websites are so awful you can't tell if the rating is continuous or peak. They're rated as dissipating 300 WH/ mile, so at 60 MPH that's 18KW. Sounds awful. It only takes 10KW to keep my Acura going 65 MPH, measured by moi.

The LEAF's curb weight is 1,450 kg--no wonder it's such a pig.

That's why a velomobile would be such fun.

Being dead can definitely change your entire perspective on life, yes.

Grins, James Arthur

Even better--we can tell 'em and get them all excited about it. Just imagine if someone boarded a plane with an LR44 in hand and a bottle of dihydrogen monoxide!

Congress and the Most Honest President must pass Vital Laws to protect us from this, and terrorists emitting dioxycarbide. It won't be cheap, but what's money when the children are at risk?

Cheers, James Arthur

As I keep saying, the gasoline powered internal combustion engine is not a problem that needs to be fixed.

Or literally overkill that by a couple orders of magnitude.

I think skin resistance might go down at high currents, too.

Can't say. I do have halucinations, which I really enjoy, but they also disappeared along with the phosphenes. Now both are back.

Being dead for a minute was really enough.

Only when they zapped me. It was the fix for A-Fib in '07. It didn't work last December but the drugs finally kicked in and it took a while longer for the rewiring to work.

Wow! The AEDs are great things, too. I see more and more of them in public places.

PP3-

Some soldier got himself a Darwin award for killing himself with a 9V battery. It's all about resistances: dry skin has high resistance, wet skin low resistance and no skin almost no resistance at all. So what did the guy do? He pierced the skin on both of his thumbs with needles that he connected to the battery terminals.

Wow! Is that for real?

I find that a bit hard to believe. When I was young, I would touch my tongue (wet, of course) to a 9V battery and get a "sour" taste.

I used to test batteries in a similar way. By the taste, one could estimate the useful life remaining. IME, 9V batteries had a sour taste when they were almost dead and were quite painful when new. I didn't test new ones much.

Good story but I have my doubts. I see some problems:

1. The contact resistance of a point contact is rather minimal and much higher resistance than it might be if the sailor had skewered both thumbs, which is unlikely.
2. The ohms scale of the Simpson 260 has a rather large internal series resistance on the 9v scales to keep from blowing up devices being measured. Only the later model Simpson 260 meters used 9v batteries. Looking at the schematic: on the Rx10K scale, I see the meter and 9v battery in series with a tangle of resistors. I'll assume the pots are at 50% and combine series connected resistors and the Rx100 scale.

-lead --+-- 22.5K -------------\ | R18,19,21 | | | \-- 3.7K -+-- Meter ---+-- 9V Batt --- +lead R2 | 50ua/250mv | | | \--- 95K ----/ R1

When the leads are shorted in the Rx100 scale, the meter be at 50ua and 250mv. The meter resistance is: 0.25V / 50*10^-6A = 5K ohms

95K across 5K has little effect so I'll ignore R1. The 14.2K collection of resistors is directly across the 9v battery, so it's contribution to the current is: 9v / 22.5K = 0.4 ma The meter contributes 50 ua = 0.050 ma for a total of about 0.45ma at full scale.

Another way to look at this is that the Simpson 260 in the Rx100 range presents a 9V battery in series with about 8K ohms.

That's considerably less current than what might be expected to cause cardiac arrest using DC (300 to 500 ma DC):

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Somehow I do not believe you. Didn't you ever lick the contacts of a 9 Volt battery?

Fred

No, unless the article messed up the numbers it was 120 miles. They listed both miles and km.

I did a google search and it seems they have a longer range battery pack so now it is...

2016 Nissan Leaf Range: 107 Or 155 Miles?

If this thing can do 130 miles on a *real* highway trip, I would consider buying one. I'd be happy at 55 MPH. I don't feel the need to drive 70 everywhere.

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Rick