Supplying 4.5 volts to something that takes 5 volts?

[xRyokenx]

For that you could try soldering them... or if not good at that or if that won't work... maybe some glue or something?

By the way, sorry if I haven't been very helpful, I've had a really odd day and I've been "out of it" all evening.

[Lord Ned]

Yeah, but I don't want to permantly damage the usb cord on my only male to female. :S

(Course there probably pretty cheap but whatever)

I may just have go without music.

[SgtM]

Take a 9v battery. Put a resistor in the middle to knock it down to 5v. Use a resistor calculator to find out what resistor you'll need. (You'll need the amperage of the device you want to charge) http://led.linear1.org/1led.wiz

[weazel6265]

Hopefully I'm not to late for your trip.Since you don't want to work with resistors, if I remember right from my physics classes a while ago, batteries add in serial but do a 1/x in parallel.

I think what would work out for 4.5 v would be to have 12 AA batteries in the following pattern: 6 serial sets of 2 parrallel batteries each (i.e. have 2 batteries in parrallel, then connect 6 of those in serial)
If my math works out it should be:

1/.75=1/1.5+1/1.5

and then 6*.75=4.5V

I have absolutely no clue what this would do to the current though, so hopefully someone else can chip in

[NightrainSrt4]

Your math looks right, assuming your equations are correct. I don't know if they are, but the math looks right.

But he is still left with the issue if 4.5V will work for something that wants 5V, of which I can't chime in about, as electricity is not my best area of knowledge.

[xmastree]

Since you don't want to work with resistors, if I remember right from my physics classes a while ago, batteries add in serial but do a 1/x in parallel.

NO!!!
Don't do that!

Two 1.5V batteries in parallel will still give 1.5V, but twice the available current.

What's wrong with something like this?

Edit: Since the battery in the MP3 player is probably a 3.6V Lion cell, then it may well charge from a 4.5V source. However, using 3xAA isn't a good idea as they may only have the capacity for one or two charges. Use bigger ones instead, like D cells.

[weazel6265]

Wow, that was stupid, I did the exact opposite of what you wanted, now that I look at it, and apparently it will fry your electronics, so don't listen to me at all.

[xRyokenx]

Wow, that was stupid, I did the exact opposite of what you wanted, now that I look at it, and apparently it will fry your electronics, so don't listen to me at all.

It was just a simple mistake dude, don't make such a big deal out of it. Happens to the best of us.

[NightrainSrt4]

Hey, at least your math 'looked' right

[John5247]

four fully charged NiCads or Ni MH at 1.2volts each is 4.8 volts - much more likely to work - but you need to buy 4 recharrgeables and a charger ...!
As long as you are certain the wires are electrically touching the USB pins, you can blob superglue over the joint - you just need to keep it all still with Blu-tak (under the plug a back down the wire a bit) untill the glue dries ... or get a soldering iron!
much cheer
John