Long ago, I docked my iPod Touch with 30-pin connector onto a cheap ghetto blaster. I cranked the volume over an extended period. Shortly thereafter, the battery of the iPod Touch could not retain a charge. I am guessing that cranking the ghetto blaster caused damaging electrical noise to spike into the iPod Touch. These days, I only connect media devices to the ghetto blaster via an old audio cable.

Now I own an iPhone SE, which I'm still paying off. I am experiencing the low charge life that iPhones are known for. If I charge it with the car's 12V source (older cars use to have cigarette lighters in the socket but mine only has a cover), I won't get caught running out of juice when I'm on the road and needing to navigate or look things up.

But I am concerned about noise damaging my much more expensive iPhone. After all, it is a car, and the power sources probably weren't designed to be steady and quiet. Heck, I imagine starting the motor causes really causes fluctuations in the 12V, and maybe when the A/C kicks in.

I can pick up a USB power adapter to plug into the 12V socket, and I always carry a USB-to-Lightning cable (expensive buggers). The USB power adapter is only a few bucks at a car accessories shop, but $20 at a national electronics store chain (for a brand that isn't exactly high end). The price difference is approximately 5-fold. And generally, one gets what one pays for.

I will go for the much cheaper alternative if the risk to my iPhone is minimal. That depends on the sensitivity of the iPhone SE to gross noise on Lightning port. I won't even say on the powering lines, as I don't know exactly how Lightning is designed, and even if there were dedicated powering lines, the adapter may inject noise on all lines.

My decision should also depend on how easy and typical it is to filter or block such gross noise. I suspect that we've been charging all manner of electronics in the car for a while now. If the technology is a commodity technology, then even cheap adapters can be expected to filter/block gross noise. There's no way to be sure without lab-testing each product; it's more a risk assessment based on what is likely.

I can boil the above down into two questions:

(1) Is the iPhone SE known to be sensitive to damage from gross noise along the Lightning port?

(2) How commoditized is the technology to block such noise in USB adapters for the 12V socket of a car?

Truly answering this requires a comprehensive study which is probably unaffordable to most. I am only seeking information that can narrow down my complete lack of familiarity with the topic of either question, and enable a judgement call to be made.

Now that I've actually taken the time to describe the problem, I can't even say that the cost difference is the motivating factor. It's more the fact that I would feel far more gratified in having made a rational decision rather than just going for higher cost, which might make no difference in quality. And if the information exists with which make a decision rather than a wild guess perhaps this might help others.

  • Your second question seems to be a totally separate question, although to be honest I'm not actually sure what you're asking in your second question? Perhaps you could clarify that or reword it?
    – Monomeeth
    Aug 23, 2018 at 2:43
  • @Monomeeth: Just wondering...does the paragraph immediately preceding the questions clarify question #2? Aug 23, 2018 at 4:27

1 Answer 1


I'm not sure how well this answers your question, but it seems the whole basis for your post is an assumption you've made about the experience you had a long time ago with an iPod Touch:

I am guessing that cranking the ghetto blaster caused damaging electrical noise to spike into the iPod Touch.

As you indicate, this is just a guess and there's no way to know what the actual cause of the iPod Touch battery no longer maintaining a charge was.

My experience

What I can tell you is that during the past 11 years:

  • I have personally owned 6 iPhones, 3 iPads, 1 iPod and 2 Apple Watches
  • My family has owned 17 iPhones, 7 iPads and 5 iPods
  • All of the above devices were charged on a regular basis using the 12v sockets of various motor vehicles, campers or caravans
  • We have used a range of 12v USB power adapters ranging from about $4 to $50 in cost
  • We have never come across any damage to any of our devices regardless of the vehicle, socket or adapter being used

In all of that experience, the only damage we've noticed is that cheaper adapters and cables end up failing sooner rather than later (i.e. sometimes they just don't work, or they blow a fuse in the vehicle). However, all iPhones, iPads, iPods and Apple Watches have survived without any damage whatsoever.

Finally, as all of these devices have internal batteries, they're less likely to suffer damage as a result of electrical noise or spikes.

  • Thanks, Monomeeth. I will get the cheap adapter, as it's more for standby than regular use. I'd like to clarify something about the answer. The problem with the iPod Touch battery charge wasn't the only reason I posted. It's also because I thought that the transients injected into a car's 12V source might be very large. But I don't actually know. Aug 23, 2018 at 4:47
  • BTW, I didn't understand the last paragraph. Perhaps I should have said sharp transients in voltage and/or current rather than noise. My concern is that they might damage charging circuitry on the device and/or the batteries themselves. Perhaps I wasn't clear about this? Aug 23, 2018 at 4:53
  • Yeah, the risk of momentary variations in current, voltage, or frequency in a 12v environment and with cheaper adaptors may be higher, but typically in the case of devices that have their own battery sources the risks are greatly diminished (for various reasons, but primarily because the device is actually running off the battery, not from the external power source). For example, a laptop connected to AC power when there's a blackout or power surge is not likely to be damaged, whereas a desktop computer with no UPS and/or power surge protection is at greater risk in the same scenario.
    – Monomeeth
    Aug 23, 2018 at 5:09
  • OK, I see what you mean. You're referring to the computational platform that hosts iOS, whereas I'm talking about damage to the charging circuitry and/or battery. And we both expect that cheaper adapters will let more of the noise and transients through. I may very well spring for the $20 adapter, if only because it is a vehicle and therefore we can expect the nominal 12V to be noisier. Thanks for clarifying. Aug 23, 2018 at 5:49

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