Test/Review of BlitzWolf 24W Dual wall charger

No, it does not.

USB charging is more complicated then just how much power the charger can supply. These are charge coding profiles that this Blitzwolf charger supports. The device you want to charge looks for a certain profile and if it does not see it then it will only charge slow. Even if the charger can supply 2.4amps.

Phones does that, but a lot of the other stuff that is powered from usb chargers do not, they will just draw the current they need.

The auto coding chip and all the amps the charger can deliver means that anything you put into the charger will charge as fast as it can (the charger will not be the limiting factor).

Thanks for taking the time to point these things out hkj, it’s very educational H)

Not all chips are equal though, some chips support more code profiles. I understand Sony, RIM and some others use different profiles that the blitzwolf chip does not appear to support. So I have to disagree that anything will charge as fast as it can, most devices, yes.

And then there are also some devices that are made to be really incompatible by looking for coding on the miniUSB/microUSB 5th pin / ID pin. Really a nasty thing to do on the manufacturers part. At least one model of Asus Transformer wants 20k ohm ID pin to ground. I had an motorola phone that also required coding on the ID pin, and would not charge at all without it. I had to make an adapter to get it to charge.

I’ve had a Blackberry phone do that to me, I plugged in a different usb cable and it displayed “not charging” or something like that. A really crappy thing to do, I got rid of it quickly.

Do charge only cables interact with chips different then if it has data or does this not make a difference?

If it really is a charge only cable (with 2 wires only / no data wires) then the device can’t communicate at all. No interaction with the chip. Smart devices like phones and tablets will only charge slow.

Got 2 of them, one white and one black.
The blank one is silent.
The white one is whinning terribly at a varying pitch, like a mosquito in you ear.

If that’s all it did it would be fine, except my Qi charging pad resets when the current reaches 650mA when plugged into this charger. It seems that the charger may interrupt power at higher currents when there is no communication. I’m not sure if this is by design, which could be a good thing against shorted cables, or if my charger is just malfunctioning.

HKJ do your high current tests utilize signaling to the chip or just use dumb positive and negative contacts to the charger?


Phones or my test do not do any signalling to the charger, this is only done in QuickCharge 2 and USB power delivery.

My guess is that you QI has a very high peak current and this trips the overload in the charger.

I can’t measure instantaneous peaks, but it builds slowly when read from my USB meter. It starts at 0mA, then rises to 650mA in a few seconds, then the voltage dips and current drops to 0 and the cycle repeats. This is also when my phone beeps indicating it just connected to the pad. When I move the cable to the dumb charger, it rises to about 700-800mA without issue and the phone remains connected.

I didn’t notice it initially because I typically always have the phone above 80% when put back on the charger and it doesn’t draw as much current when charging from that level.


The particular auto coding chip used in this blitzwolf charger does not include the ability to interrupt the power (that’s why there is no individual port overload protection here). The usb power does not pass through this auto coding chip.

Did you say your blitzwolf charger makes noise / whines? Any problems using touchscreens on a phone or tablet while charging directly from the blitzwolf (not via Qi)?

What brand is your Qi transmitter pad? Or link to where you purchased it?

I have not seen any auto coding chip that controls power yet and it has nothing with individual port protection to do.

Texas Instruments TPS2511 USB Dedicated Charging Port Controller and Current Limiting Power Switch. Datasheet
Several other chips are available that can be used in AC wall adapter usb power supplies / list that as an application but aren’t solely dedicated to that use, they include usb 2.0 data passthrough in addition to auto coding.

Yes chip exists, but I have not seen it used in any of the usb power adapters I have tested, even if they have over current protection.

I’m using a CHOE Stadium Qi 3 coil charger bought from Amazon. It works fine with other USB chargers, just not my Blitzwolfs and I tried both. As soon as the USB meter shows 650mA, the phone beeps, the voltage dips to 5.0 from 5.2ish and current drops to 0mA then climbs again and the cycle repeats. If I plug it into another USB charger, without moving the pad or phone, the current gets up to 750mA-850mA and the pad functions normally. As for noise, I haven’t noticed any and there are no issues with the touchscreen when charging. I’m quite familiar with that phenomenon when using really cheap chargers.


One significant different between the BlitzWolf and many cheap chargers is that it maintains the output voltage until it turns off due to overload, on many of the cheaper ones the voltage will drop (This will reduce the current draw).

I’ve seen that too with the cheap chargers, but the one I have which works stays above 5V up to an amp. It’s rated for 2 amps, but I haven’t been able to find my USB discharge resistor to test it or the BlitzWolf. Also, I wouldn’t think that 650mA is considered overload voltage, unless there is something in it that enforces low current only when connected to non-negotiating devices.


I have noticed instantly that while having these plugged into my Samsung smartphone and also having my headphones plugged into the smartphone there is clear humm sound coming through the headphones otherwise on a clean no-buzz rig. Of course other 3 other power supplies do not make any humm what so ever to the headphone's output. This comes as a surprise as I have never heard ever before a 5V source to add noises(in his case a humm) into the headphones on any device I have used for listening music.

No buzz / humm if playing music via the phone’s speaker, just headphones only?