USB Charger Doctor Review

The USB Charger Doctor is a small device that goes in series with your usb cable to measure the devices voltage and current consumption. It can be purchased for around $3 overseas on eBay or $4-5 on eBay from a retailer that has already imported the unit.

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iceberg789 says:

reading fluctuates a lot.

Stephanie Ann says:

Can you suggest a name of volt meter that doesnt use a usb plug?

Ropo Man says:

Bought mine for 1.98$ but it always displays 0.00A. V seems to work o.k.

bmo says:

How much power does the Charger Doctor itself consume?

By the way, the left speaker’s not working

Srednio naJeza says:

I purchase one and it’s fine.My LG 700mA charger can do 800mA and cheap small 1A give me only 600mA LOL.The short cable give’s even two times more mA !.Thanks for movie bro !. BTW.SRY. for my English

DjNRG84 says:

Hello, how to know which device is mailfunctioned with USB Charger Doctor? Is it phone battery or charger wrong, and how to know that? Tnx!

Stephanie Ann says:

Can you suggest a name of volt meter that doesnt use a usb plug?

Ian W says:

Amperage is not a word or unit of power otherwise I’m getting one.

David Fielder says:

What is that tool with the 18650 battery that you tested?

FireSwordl says:

Great video again. Interesting device. Your concept with solar panels, supercapc, zmdi module , etc.. can be used for a ton of things 🙂 As far for this “doctor” I can make a toy car running on 2 supercaps 2×2.7V in parallel, which I want to charge in the computer USB. I will put a limiting resistor, so that the amperage is not higher than (lets say) 400mA, but with this device, I can make a very fine monitoring, how the car is charging.

Brian Tumor says:

I’m surprised that you used your anal vibrator as a demo.

Rob Fern says:

what was that second item you plugged in? something grip????

Roelio says:

Dear Sir, 

Thanks so much for your review ! But what will happen if I go measure more then the max 3 amp’s will it blow up the Charger Doctor unit itself ?

I ask this question because I want to convert this to a 510 e-cig in and output. Will it blow up if I measure 5 amp for example?


zapro_dk says:

Good review 🙂 Fyi, R050 is 50 MilliOhms. The IC used is a cheap RISC micro, OTP or Mask-programmed. PIC’s are too expensive, and afaik they donot exsist in that size of ic-case

Mr Bob says:

Does this work the other way?  e.g. I want to test the output from a powerbank charger to my phone.  I can charge up the powerbank and led’s indicate full and when connected to phone I get charging x% on phone, but does not charge and  seems to discharge faster instead… 

David B says:

Anyone any idea why my Charger Doctor would give strange readings like this when connected to a PC USB.
Tried various USB sources and all give strange readings..
e.g.. A wall charger for my Nexus 7 gives a reading of 17v.. which is obviously wrong! lol
Here’s a macro of the PCB if anyone can identify a problem.. or it may just be down to a faulty code been written to the chip?

hamrad88 says:

Which eBay dealer did you get this from?  Too many choices.


Anonymous says:

Where did you purchase that electronics table, I like it….

Martin Hroudný says:

How many mA is self-consumption?

brown oskar says:

3.99 here

Hui Wijaya says:

i have this device, but compared with my usb current probe diy, the current measured using this device was lower than mine usb current probe while this device showed 1.54A, and my device made up using amp meter digital showed 1.78A, and the voltage measured by this device also showing wrong about 0.01- 0.02V and when using multimeter digital measured just show the same as my usb current probe made by me  , very strange.. and doesnt like my expected.. 🙁 …

Michaël Colignon says:

mastech 8218 ?

I was here says:

I bought one so I know my ecig is fully charged…. How do I know it’s fully charged?
Wil the Amps and volts read 0.00?

Charles Murray says:

Hi, thanks for posting this.Will this USB doctor be useful for eliminating which of my USB cables are better than other ones and which are carrying a charge at an inferior rare?

John Strabismus says:

I never heard of this device, but it looks like you have some good ideas for using it.

1wor1d says:

USB Doctor charger is now selling for as cheap as US$2 on eBay inc delivery.
I used my one to check my phone chargers and USB cords.
All those seemingly identical USB cords and chargers you have are infact quite different as far as current flow goes, with this device you can find your best cords and chargers and use them to charge your phone and other items and give the crap ones to your friends “as a gift”!!

405line says:

Great review

Just got one of these from Ebay…irreplaceable for checking the “USB device requested charge rate above 100ma” otherwise known as the charging rate, for example when using an android with OTG charging (it’s a “trick mode” after rooting and installing a custom kernal which also allows the device to “negotiate” 500ma from USB amongst other things) it’s fiddly (correction it’s hit-and-miss) to know when it’s requesting the correct amps when in this it can be seen when it’s set up correctly…LED’s are a bonus as easy to see even in daylight, the the only thing missing is that there is no function hold (hack?), however the auto toggle is good enough…a great device for those who can’t sleep at night not knowing how (or why) many amps their android is pulling in “trick” mode and why the device is perhaps discharging (very slowly and slower than normal) despite reporting being charging etc.

ffsBorthwick says:

does it only measure up to 5 volts?

Burlington island keeper nj says:

Thank you.

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