Can I use a multimeter to test my USB passthrough battery -- computer USB

[wefishallday]

I've read many posts here on how to use a multimeter to test batteries and cartomizers.

But -- can't find anywhere that a multimeter can (or should) be used to test the 5 Volt USB passthrough battery that connects to my PC.

Wouldn't it be potentially harmful to my computer to test the USB Passthru battery when its plugged in, but, if so, how does one test the USB Passthrough battery if it's not plugged in?

Perhaps I'm wrong, but my understanding of the USB passthrough battery is that it does NOT have a charge on its own -- only when connected. Thus the question.

Thanks for any help, and please correct any misunderstandings I may have.

 

[Kurt]

I think you are mistakenly calling the part that plugs into the USB and that you screw the atty into a battery. It is not a battery, which is why it does not carry its own charge when unplugged. It is simply a conduit with a switch to get 5V USB from the port to the atty, so essentially a wire with a switch (button to activate the atty) in a sheath that looks like a 510 battery.

There are ways of measuring voltage on a device like this, but it is not as easy as touching multimeter leads to certain places and pressing the battery. At least I don't think it is. Scottbee has built a screw in device that can measure this. It is described in this thread:

http://www.e-cigarette-forum.com/forum/joye-510/65055-battery-voltages-surprise.html

Perhaps another vet knows of another way of doing this. The point of that thread was to show that regular 510 batts under load did not generate 3.7V to the atty, more like 3.2V. I do believe that a 5V PT does, on the other hand, deliver 5V to the coil.

This all said, you should not be using your 5V PT on a computer USB port, regardless of the rhetoric the vendor used. With a regular 510 atty (say 2.5 ohm), this will be drawing 2 amps from the port, which is in general way beyond their rating, and may well fry the port, and possibly the motherboard. Use an external AC/USB converter (I got a 2.5 amp one from Radioshack). Even a powered USB hub can be underrated enough to fry. Most USB ports are rated to about 500 mA or less, and even battery-box type PTs can have recharging current draw that fries computer ports.