Maybe it's my magnetic personality.

February 13, 2007 1:24 PM

My BART card keeps getting demagnetized. Is there anything I can do to make it last longer?

About every third or fourth trip on BART my card dies. The BART agents tell me it's my iPod, or my cellphone, or a magnet somewhere. I've become religiously anti-magnet when shopping for new bags. I've even taken to keeping my BART card in a jacket pocket instead of in my bag, but that doesn't seem to make much of a difference.

Google searches turn up products like this which claim to prevent demagnetization. I'm a little dubious though- "a coat of demagnetization-proof material", without being more specific, sounds fishy. What materials are demagnetization-proof, anyway?

I'm hoping one of my fellow transit-riding, iPod-listening, cellphone-carrying MeFites has figured out a solution for this.

posted by ambrosia to science & nature (22 comments total)

i had the same problem until i started keeping mine in one of the crappy cardboard sleeves available at the kiosks. no more demag...
posted by casconed at 1:34 PM on February 13, 2007

Mine lasts forever, so something about your pockets or your routine is probably doing it. None of those devices you're carrying should create a significant magnetic field beyond an inch or two away, so if you're keeping it in a different pocket that's probably not it.

There are materials that will affect magnetic fields, and bend them around. That's how magnetically shielded loudspeakers work. I don't know if that wallet is legit or just a hoax, though.

Your credit cards and cetera don't have any troubles? I assume that you started out keeping your Bart pass with them? Very strange.

Do you work in an MRI lab or something? :D
posted by aubilenon at 1:35 PM on February 13, 2007

Do you always enter and exit the BART system through the same faregate every day, or perhaps you're taking a different path on demagnetization days? Some of the faregates themselves do some rather heinous things to inserted cards.
posted by majick at 1:38 PM on February 13, 2007

Keep the card in a sleeve or wallet, and only remove it when you need to use it.
posted by welephant at 1:38 PM on February 13, 2007

to clarify: I have one of those crappy cardboard cardholders they give you at the kiosks. And I normally kept my BART card, in the cardholder, in my wallet with all my other cards, none of which have ever demagnetized.

and no, I don't work in an MRI lab or anything. If I did, I'd probably know the answer to my question...
posted by ambrosia at 1:41 PM on February 13, 2007

I have the same problem constantly. I now keep my BART card away from other credit cards in my jacket pocket, away from my cellphone, iPod, digital camera, GPS system, etc.

Still, one out of 10 trips ends in a demagnetized card, so I just got my EZ Rider card. No magnetic strip, thus no demag, thus none of that "fill out this form and we'll send you a new BART card in 30 days" stuff.
posted by Gucky at 1:58 PM on February 13, 2007

not really an answer, but i want to second gucky about the EZ rider card. here's the information about it. it took about two weeks for me to get my card and i love it.
posted by kendrak at 2:14 PM on February 13, 2007

Do you pass through a metal detector on your journey? I am told that these can demagnetise cards.
posted by welephant at 2:24 PM on February 13, 2007

There is such a thing as magnetic shielding. But that wallet's claim to unspecified "demagnetization-proof material" still sounds awfully fishy.
posted by Zed_Lopez at 2:39 PM on February 13, 2007

Hrm. I used to rubber band my BART tickets to my iPod and never had them demagnitize.

Where do you store them when you get home? Leaving them too close to a large speaker? Sticking them to a fridge with a magnet? (hey, it happens!)
posted by drstein at 2:46 PM on February 13, 2007

The TransLink Card is available now, but won't be implemented at all BART stations until later in the year (I use it on the ferry)-- it will eventually work for nearly all Bay Area transit, including Muni. I've used it on BART, but it's a big pain in the ass if you get off at a stop without the transponders in service yet. So, not a very useful recommendation right now, but you'll want one eventually. It has an RFID chip, not a magnetic strip.

...and I don't know why you're de-magging. I put such small amounts of money on mine that they are always being replaced in the add value machines.
posted by obloquy at 3:03 PM on February 13, 2007

Do you carry a compass? I once gave my family a bunch of compass key rings and then had to run for my life when all of their credit cards were demagnetized.
posted by astruc at 3:42 PM on February 13, 2007

This seems to be a grand mystery. This guy is having the same problem.

Anecdotally, I've used BART for years and have shoved them up next to ipods, cellphones etc., left them lying all around the house, and NEVER ever had one demagnetize.

Maybe its body chemistry?
posted by vacapinta at 3:51 PM on February 13, 2007

I keep mine in a separate little leather wallet thing with a couple of credit cards in my jacket pocket. It's very, very rare that I end up with a demagnetized card. I never put my ipod in that pocket OR keep that wallet thing next to the key card from my office, but that's just in case -- I've not had this demagnetizing problem.
posted by Lockjaw at 4:04 PM on February 13, 2007

This happens to my girlfriend all the time. She keeps her BART card in her wallet, along with her Fast pass, credit cards, etc. Nothing else gets demagnetized.
posted by rtha at 4:26 PM on February 13, 2007

I had this problem when I lived in SF. I was told that it was my cellphone, ipod, other credit cards (wtf?). Nothing else would get demagnetized, just the bart ticket.

I finally figured out (I think) that it was actually my jacket by process of elimination. I had a certain jacket.. I don't know what was in the fabric or lining or something that did this, but everytime I'd wear it and put my ticket in the pocket, it would demagnetize. It was just a normal long green coat.

Good luck with your's. I think the tickets are just super sensitive and it's just a matter of figuring out what you normally wear/carry that's doing it.
posted by mileena at 5:10 PM on February 13, 2007

Way back when I had an eelskin wallet. I loved it, but it demagged all my credit cards and such. At least, someone told me it could do that, and when I got a new wallet, it stopped happening. If you've switched where you keep it and it still happens, that's probably not it, but it's one data point, anyway.
posted by ctmf at 6:38 PM on February 13, 2007

Oh yeah, if it gets demagnitized, BART will replace the ticket for you.

My friend that stuck her ticket to the fridge with a magnet? Yeah, BART employees just giggled and cheerfully replaced the ticket for her. There's a service counter in the Embarcadero station.
posted by drstein at 10:32 PM on February 13, 2007

All mag strips are not equal. I have a cinema discount card that demags all the time, whle none of my other cards make trouble. (And I blasted the cinema company when they attempted to demand I pay for a replacement card, and they backed down).

Funny enough, this only ever happened once when I had DC Metro cards.
posted by Goofyy at 6:45 AM on February 14, 2007

Oh yeah, if it gets demagnitized, BART will replace the ticket for you.

Unless you paid for your pass with a crdit card. Then you have to fill out a form and wait 6-8 weeks. I've filled out about 15 of them and have yet to get a BART card in return. Now, I just don't put more than $10 on a card.
posted by Gucky at 10:43 AM on February 14, 2007

"Unless you paid for your pass with a crdit card"

I never had that problem. Unless that's a new policy or something.
posted by drstein at 2:04 PM on February 25, 2007

Ah, maybe something HAS changed recently.


http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/03/09/BAGREOIB221.DTL
posted by drstein at 11:01 AM on March 9, 2007