Car Chargers Keep Blowing Out

I got SIRIUS satellite car kit which plugs into the electrical outlets in my Honda Accord (2004) and the first one died after less than a week, then I exchanged it for a new charger and that one died in 5 minutes. I was then thrilled to find that a charger I have for another device matches the specifications of the Sirius charger, so was using that and now this morning that charger is dead. I'm starting to wonder if maybe a power surge is causing this? Should I always unplug these chargers when I turn off the car, and not plug them in again until the car has been started? I took the one charger apart...can I repair it by just replacing the little cylinder fuse inside? Are they easy to find? Any help would be appreciated.

Reply to
jeffy3
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If you are referring to a glass cylinder with metal caps and a thin (but broken) wire between them, yes. Go to any auto parts store, and they will have a fuse of the proper length and amperage. Don't be tempted to replace it with a higher amperage fuse though, it's a good way to have other, more serious problems, including a fire.

If you are burning out chargers at that rate, you should entertain the possibility that your radio is drawing more than it's designed amperage, which could indicate an internal short, or possibly a bad ground, which is less likely . I would go back to the dealer where I bought the radio and have them check it for abnormally high amperage draw. I'd bet on this being a radio problem rather than a charger or car power outlet problem.

Reply to
Steppenwolf

Thanks very much for the reply. It's a portable Sirius radio unit. If it helps to narrow down the problem, this is the second radio too. When I went to exchange the car charger, I had to also exchange the radio itself (for inventory/returns purposes). So if it's the radio causing the problem if it's happened with two different units, does that change your opinion in any way? Thanks much.

Reply to
jeffy3

If the fuses are burning out, it is due to more current flowing through the fuse than it was designed to handle. There are at least four reasons why this could happen:

  1. Your alternator is operating at too high a voltage. If your car regularly burns out other fuses in other circuits, this would be the most likely culprit. But, have it checked anyway if you think this might be the problem.
  2. The radio is drawing excessive current due to some internal flaw. This is less likely, since you have gone through two radios with the same problem. But maybe it is a bad design.
  3. The charger design is faulty. The fact that a different charger also blew a fuse is not compelling evidence to me, because I do not know that the specifications on the other chjarger really exceeded the specifications on the charger that came with the unit.
  4. There is a fault (intermittent open) in the power outlet or its circuit. If the radio has its own internal rechargeable batteries, it might run off of internal power when the external power was off, so you might not notice it. The intermittent open causes excessive thermal shock to the fusible wire, causing it to fail.

There are probably other possibilities that I have not thought of. Somebody else will.

Hope this helps

Elliot Richmond Freelance Science Writer and Editor

Reply to
Elliot Richmond

Thanks very much. THis does help. How do i determine if it even is a blown fuse? Is it visible to the naked eye?

Reply to
jeffy3

Yes. You say you have taken one of the chargers apart and you saw something that looked like a fuse (small glass cylinder with metal cap on each end). You should be able to see a small wire running through the cylinder between the metal caps.

Elliot Richmond Freelance Science Writer and Editor

Reply to
Elliot Richmond

I would be less inclined to blame the radio knowing that it had been changed as well, and would look at the wiring more closely for a short or a poor ground. The first thing I would want to do is to find out how much current (amperage) draw the unit has while running. For instance, if it was protected by a 14 amp fuse and drawing 10 amps regularly, (just as an example) this might be enough to blow the fuse after a few days but not right as soon as it is plugged in.

Maybe Tegger or some of the other guys here might give you a more current (ouch!) answer. I'm 35 years away from twisting wrenches for a living.

Reply to
Steppenwolf

Thanks much. Went to Radio Shack to get a replacement fuse (which were naturally out of stock) and the manager guy there told me in general it's not a good idea to have any charger plugged in until the car has been started because it may not handle the power surge. Seems like a lame answer to me.

Reply to
jeffy3

I'm not exactly sure which 'replacement fuse' you are replacing? Fuse inside the charger or one inside car? If a car fuse is blowing, then the charger plug (into Honda power outlet) may be shorting. This because a charger's plug is not properly designed to not shift.

Fuses blow typically because hardware has failed. Fuses do not protect hardware. Fuses are for human safety; so that failed hardware does not kill humans.

If "the manager guy there told me in general it's not a good idea to have any charger plugged in until the car has been started because it may not handle the power surge", then that charger is defective by design. SAE and ISO standards are explicit. Charger can experience up to (if I remember) 230 volts on 12 volt supply. A charger should withstand at least 60 volts due to a rare condition that all vehicle electronics must withstand without damage: load dump.

IOW start a car every time and have no electronics damaged. How often is the car computer destroyed by a startup surge? This was standard probably longer than you have existed. The Radio Shack manager would be hyping a myth.

But aga> Thanks much. Went to Radio Shack to get a replacement fuse (which were

Reply to
w_tom

Most modern high current electronic devices use switch-mode power supplies, which are compact, inexpensive and efficient. One of the peculiarities of switch-mode supplies is that they draw more current at lower voltages (pretty much constant power), so if you are trying to power them while cranking the current may be too high.

While you are looking at it, jeffy, if the fuse is in the part that plugs into the socket unplug it and give it a feel after it has run a minute to see if it is hot. It may be that the socket is bad (oxidized center contact) and is simply overheating the fuse.

Mike

Reply to
Michael Pardee

I really appreciate everyone's thoughts. It's all pretty interesting to me , although frustrating too. TO answer W_Tom's question, it is the fuse inside the car chargers that keep blowing...and it doesn't happen on the car charger for my MP3 player or my cell phone...it's only happening with the ones using the Sirius radios....last night I put a new fuse in and made sure to have it unplugged from the socket before starting the car and so far, so good...the other thing I should add is that there are two sockets in my car, one in the between the seats console and one under the dash....I haven't been able to pinpoint if both are causing the fuse blowouts or not...maybe I should buy a bunch of fuses and do a lot of testing with each socket to see if it's one or both that are causing the blowouts.

Reply to
jeffy3

A short ciricuit before the fuse will not blow a fuse. If the fuse "is the fuse inside the car chargers", then short circuit that can blow the fuse is insiide Sirrius equipment - not in a power outlet.

BTW, what numbers def> I really appreciate everyone's thoughts. It's all pretty interesting to

Reply to
w_tom

Also an Accord 2004, I had a problem with cell phone charger. The charger worked fine in other cars, but blew the Honda fuse immediately. Honda dealer said yeah, they've seen that a lot, that Honda sockets are "funky". A new charger has worked for me, the few times I've used it, though I expect it to blow at any time. Beats me what the actual problem is.

J.

Reply to
JXStern

Appreciate the info. I've learned that you don't need to buy a new charger, just change the fuse. You can get 4 for about a buck fifty.

Reply to
jeffy3

But jeffy3 says fuses > Appreciate the info. I've learned that you don't need to buy a new

Reply to
w_tom

There are two ways it can blow the fuse in the charger. The first is if the fuse is in the plug - a common location. In that case the poor connection conducts heat straight into the fuse. The second is if the poor connection reduces the voltage into the charger to the extent that the charger draws too much current in order to supply the required power. Either of those is not unusual.

Mike

Reply to
Michael Pardee

The fuses are the 5x20 mm 2 amp 250v

Reply to
jeffy3

Reply to
w_tom

To be clear, mine was blowing the Honda fuse immediately, dealer when through a handfull just showing me what was going on.

J.

Reply to
JXStern

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