Toyota Prius Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
1,215 Posts
Discussion Starter #1
EDIT: Since originally making this post, I read a couple of prior threads on EM fields and the concern that one poster had for health issues. I'm really not concerned about health aspects (my comment below about my brother-in-law is purely tongue-in-cheek!) of my soon-to-be-delivered Prius Silver #9. But I did think maybe it would be wise to modify the "subject" of this post (and put this blurb in) so that my question wouldn't be inadvertently passed off by potential readers as "oh another one of THOSE guys..."
END-EDIT

Okay, I figure my Prius will be well-shielded from stray electromagnetic, krypton, gamma-ray, and antimatter-injector-manifold radiations, and the roof will probably offer reasonable shielding from mother Sol's UV rays, too.

But I am curious....and I have to ask.......

Will my backseat passengers run the risk of having their credit cards and ATM cards erased while nearly sitting on my NMH battery pack? Will my laptop's hard drive be safe in the trunk? Will my brother-in-law be rendered sterile?

:shock:

I'm assuming that the shielding will be more than adequate, but hmmmm....there are those neato spinning-magnet motors and batteries and such in the car...

Thanks in advance for any information you can provide.
 

·
Registered
Joined
·
150 Posts
Only mentally sterile.

I would not worry about your computer. If it can survive the X-ray machine at the airport, it can survive in your truck. I would worry about heat rathern than magnatism in the trunk.
 

·
Registered
Joined
·
928 Posts
My laptop has survived several trips sitting on the HV battery shelf of my 2001 Prius with no problems. Over the past 3 years, several people in my lunch group have ridden in the back of my Prius on a daily rotating basis. None have complained of ATM/credit card erasures, or sterility for that matter :)
 

·
Registered
Joined
·
884 Posts
You probably don't have to worry about electromagnetic fields erasing your PC hard drives and ATM cards for items stored in the trunk or back seat. The batteries in the trunk are DC. Strong electromagnetic fields are generated by AC, pulsating DC and arcing high-voltage, not any of which are in the trunk, under normal operation conditions.

You might have some trouble if you strapped your laptop to the inverter (hybrid module) in the engine compartment, with the module cover removed, or to the side of the electric motor or generator. Otherwise, you laptop hard drive and credit cards are probably safe.

Hard drives have their own shielding, and credit cards and other magnetic stripe/tape devices take a really strong magnetic field or a lot of RF energy to erase. Have you ever tried to erase a floppy disk with a bulk tape eraser? It is really difficult, and this is a very strong electromagnetic field.
 

·
Registered
Joined
·
928 Posts
With my miniscanner (thanks Graham), I've seen the DC current switch from almost 80 amps out of the battery to almost 60 amps into the battery in less than 1 second. That's about the pulsiest DC I can get from it. It doesn't seem to hurt my laptop sitting on the battery shelf in the trunk.

To achieve this pulse, floor it up to 55 MPH, then fully release the accelerator pedal. Since sudden changes in load cause an engine to pollute, the Prius replaces the acceleration load on the engine with generator load, then backs the load off over the course of a few seconds.
 

·
Registered
Joined
·
884 Posts
Electromagnetic Fields in the Trunk

I guess I should have qualified my statement (though I tend to ramble-on way past what most people find interesting or of much use).

That big switch in DC current does generate a magnetic field, but the cables and batteries are inside a shielded compartment and conduit. Also, a straight wire/cable does not concentrate the field like a tightly coiled wire does (like in an electromagnet or motor). A single pulse produces a magnetic field around the wire while the current is building, subsiding and reversing; but it is relatively weak and shielded from radiating into the trunk and passenger compartment. Also, the field strength weakens according to the "inverse-square law", so it rapidly fades the farther away you get from the wire.

While DC works well for electric motors, there are many advantages to using AC, among them the ability to increase current by adding phases. I believe the Prius inverter produces two or three phase AC at a higher frequency than household AC. That allows a smaller cable to carry more power. Also multiple phase electric motors are more efficient and generate more torque.

I'll get the Prius manual out, if anybody is interested; but I know my wife would be turning her eyes up right now and walking away, if she was listening to this. So, I'll stop and assume that this is enough detail for most people.

I hope I don't seem condescending; as I don't mean to be -- I'm just an old geezer that knows little snippets about a whole lot of basically uninteresting, useless stuff.
 

·
Registered
Joined
·
1,215 Posts
Discussion Starter #7
Re: Electromagnetic Fields in the Trunk

Phoenix said:
......
I'll get the Prius manual out, if anybody is interested; but I know my wife would be turning her eyes up right now and walking away, if she was listening to this. So, I'll stop and assume that this is enough detail for most people.
Yeah, I had a girlfriend like that once...

Phoenix said:
I hope I don't seem condescending; as I don't mean to be -- I'm just an old geezer that knows little snippets about a whole lot of basically uninteresting, useless stuff.
Don't worry...I'm a not-so-old geezer who also knows little snippets about useless stuff too...my friends are all rolling their eyes at me...."two electric motors", "MG1 and MG2"....."planetary gear?" "CVT?" :roll:

And then after all that! I still get the "how often do you plug it in?" :shock: And I know they weren't paying attention anyway...


Hey, folks...thanks for the great responses, and for the reassuring information. I consider my question quite well-answered, and this issue to be pretty much closed at this point, but if anybody has additional supplemental information, please don't hesitate to add it.

Thanks again!!
 

·
Registered
Joined
·
623 Posts
And then after all that! I still get the "how often do you plug it in?" And I know they weren't paying attention anyway...
Odd. Nobody has ever asked me about plugging in my Prius. I tell them that the gas engine charges the battery, and they seem okay with that.
 

·
Registered
Joined
·
6 Posts
I'm still awaiting my '04 Prius, but if anyone is interested I will take a gauss meter from work and sniff around the relevant areas of the car while someone else is driving. Once I decide to let someone else drive my new baby, that is. :)
 
1 - 9 of 9 Posts
Top