Car battery charging, via usb

[Paul Frost]

Hello, everyone, i have a seemingly silly question that came into my mind half an hour ago.
I have a spare battery 12v 10Ah
but i need a battery charger to charge it, is it possible to use the 5v of usb power to charge a battery, or maybe using my laptop adapter of 19v,
this is all temporary, till i get a real battery charger, but still a temporary fix would be awesome.

 

[Paul Frost]

anyone ?

 

[Paul Frost]

Bump

 

[mymutter]

No, it will not work at all, and will probably just kill the charger in minutes, if not seconds.

The only real solution is to get a battery charger that is designed to charge car batteries (or an AGM charger if you have an AGM battery)

 

[Paul Frost]

No, it will not work at all, and will probably just kill the charger in minutes, if not seconds.

The only real solution is to get a battery charger that is designed to charge car batteries (or an AGM charger if you have an AGM battery)

Oh ok, thanks.

 

[bryanl]

I'm assuming you're referring to a lead-acid battery because lithium batteries have very particular charging requirements and can literally explode if they're not met.

You can't charge a 12V battery from a USB port's 5V unless you feed the 5V into a boost regulator that increases it to about 13.6V and limits the current to 1A or less for a 10AH battery. USB 2 officially puts out up to .5A, so at best you can get 5/13.6ths of this, or .184A. A 19V laptop adapter with a 10-20 ohms or higher resistor in series to limit the current will also work. The resistor should also be rated for at least 20 watts to avoid overheating.

 

[simonmarkis]

Or you can always get yourself a good power converter.