Test/Review of BlitzWolf 48W 4-port smart car charger C1

BlitzWolf 48W 4-port smart car charger C1

Official specifications:

  • Model:BW-C1
  • Input: DC 12-24V Max
  • Output: DC 4x2.4A/5V Max
  • Size: 45mm * 86.7mm * 21mm (3.46 x 1.77 x 0.79 in)
  • Weight: 32.4g

I got it from Banggood

I got this charger in a fairly plain cardboard box.

The box contained the charger and a instruction sheet.

The charger exists in black and white versions.

What cannot be seen on the pictures is the blue led inside the charger, this means there is a blue glow from the two center usb ports when the charger is powered.


  • Power consumption when idle is 0.2 watt at 12V and 0.4 watt at 24V
  • All outputs are in parallel.
  • No individual port overload protection.
  • Usb port coding is automatic selected (Up to Apple 2.5A).

A load sweep on a single channel, there is no overload protection on the output. The efficiency in the charger is good.

The above is minimum and maximum voltage in a typical car with all four outputs in parallel. The charger has a common overload protection that trips at about 10.5A, this matches fine with the rated 9.6A total current.
With four cables the connection and cable loss is lower and the efficiency looks even better.

I did also try with 24 volt input, this also looks good.

The other charge, there is a small difference in overload trip current.

The charger needs a bit of idle current, it is nearly constant in the rated range and will drop at lower voltages.

At full load the charger turns off somewhere between 9 and 10 volt. The input current varies with voltage, about 4.5A at 12 volt and 2.2A at 24 volt.

Output voltage and efficiency is fairly stable over the specified range.

The charger can also maintain full output for one hour, the noise at 45 minute is because I moved it to take IR photos and a car power socket do not give a complete stable power connection with movement.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.

M1: 51,9°C, M2: 72,2°C, M3: 50,4°C, M4: 46,1°C, HS1: 77,1°C
HS1 is probably the inductor.

M1: 51,8°C, M2: 68,9°C, M3: 44,7°C, HS1: 75,7°C

M1: 51,2°C, M2: 67,4°C, M3: 44,8°C, M4: 39,6°C, HS1: 74,3°C

At 0.5A with 12V input the noise is 12mV rms and 60mVpp.

At 2.5A with 12V input the noise is 12mV rms and 56mVpp.

At 2.5A with 24 volt input the noise is 14mV rms and 61mVpp.

At 10A with 12V input the noise is 17mV rms and 66mVpp.

At 10A with 24V input the noise is 21mV rms and 84mVpp.

Tear down

It was fairly easy to open with my vice, but I did damage it.

There are two circuit boards, one with usb connectors and one with the buck converter.

The circuit board with usb connectors had some isolation on the backside.

Inside the tip is a spring.

On the topside of the circuit board there is not many parts: A ferrite bead (L2) at the input, some capacitors and a inductor (L1).

But hidden below the inductor is two transistors (Q1 & Q2).

On the other side is the controller IC. It looks like the transistors and the IC is a set, the type numbers are: EP809, EP808-A & EP808-B.
There is no rectifier diode, this means that one of the two transistors must be used for synchronous rectification. This is one of the reasons for the high efficiency.

The circuit board for the usb connectors has space for 3 leds, but only one is mounted.

On the other side of the circuit board is two chips for the automatic coding.

In this side view the led between the two usb connector blocks can be seen.

Beeing a 12/24V device there is no need to test with high voltages.


I am fairly impressed with this car adapter, it can deliver a lot of power with good efficiency, but as usual I have a few details that could be improved:
I would have liked the blue led visible from outside, even with all four usb outputs in use.
The charger can deliver up to 10A into a single usb plug, this is too much.

I will call it a good charger (If each output had been limited to about 3A I would have called it very good).


The usb power supply was supplied by Banggood for a review.

Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger

Very nice review as always HKJ.
Too bad it doesn’t have overload protection

It do have overload protection, but only a common one.

You mention that this usb charger can deliver up to 10A on single port.
when it happen? And is this usb charger got a fuse?

Whoa. Thanks as usual man. Already ordered 3 of those. Not sure what 10A to a single USB would mean ….

Can it fry a battery or something?

You have 3 cars? I have one on the way too.

Lol no. 1 for me and 2 for friends :stuck_out_tongue: I wish I had at least 2 cars though!

Yes, the overload protection is at 10A. I did not spot any fuses in it.

The 10A is only a problem if you have a defective cable or device, then you usb cable might melt and in extreme conditions catch fire.

Thanks for the info HKJ.
This charger In my wishlist :slight_smile:

I keep wondering, how easy would it be to add the 3A protection to each port? Is there room in the charger as it is?

It would depend on what type of chip you could find for the job. In some chargers it is made with resistors, transistors and a OpAmp and it do use a lot of space and produces some heat. I have seen one charger where they had a single protection chip for each output.

This could be dangerous, if you charge something in the car and forger about it. Could also drain your car battery fairly quickly at 10A.

The charger is not drawing 10A from you car battery, "only" about 4.5A. This will also drain you car battery if you have connected something that continues to use power and the socket has power when the ignition is off.

Thanks for the review HKJ

The XTAR VC4 Universal will be safe using this car charger?

Should 2 D batteries or 18650s be able to charge with the engine off? How many batteries should a car battery be able to charge without running the engine?


It is best not to discharge a car battery below 50%, with that in mind a simple guide is not to charge more Ah, than the car battery is rated. I.e. with a 60Ah battery, do not charge more than 60000mAh LiIon cells. I am a bit chicken and would stay well below that value.

It is nice to have some chargers I can trust HKJ, until you started reviewing and discussing them, I just assumed they were all whatever they said they were, and all pretty much made the same/equal, and all more or less, equally safe.

Unfortunately this charger is making FM radio interference in 4 cars and 3 different chargers I tested.
As long as you are close to transmitter there is no problem. Since I travel a lot it is annoying.

Mike, I’ve got a bit of knowledge of dashcams, their PS’s, and RF interference and this is similar. Some cures have been effected with shielded USB cables and as you’d know being a Ham distance from antennas and other RF entry points should be as big as possible from devices emitting RFI. My old NiMh charger has to stay across the room from my radios but at least it’s not in the farthest room!


I know RFI is an issue HKJ can’t test for as he’s said his whole environment is noisy with RFI.

I’d sure welcome more reports from users. I’m always tracking down electronic noise, just by carrying a little AM transistor radio around.
It’s amazing how noisy the new LED bulbs and any small import electronics are.

My hunch is the FCC labels on most of that stuff are just fakes with no testing done at all.