Olaf Dual Car charge with display 2.1A
![DSC_0312](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0312.jpg)
Official specifications:
- Input: 5V/2A A car is 12V or 24V, not 5V. On of the slides correctly shows: DC 12-24V
- Quality Certification: CE,CCC
- Output Interface: USB
- Power Source: A.C. Source A car is DC, not AC
- Support Quick Charge Technology: No
- USB Ports: 2
- Model Number: USB Charger,USB Adapter,Phone Charger
- Output: 5V/2.1A
I got it from Aliexpress dealer: TwitchDirect Store
No fancy box for this charge, just an envelope and a plastic bag.
![DSC_0317](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0317.jpg)
![DSC_0314](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0314.jpg)
![DSC_0315](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0315.jpg)
![DSC_0316](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0316.jpg)
![DSC_0868](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0868.jpg)
![DSC_0869](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0869.jpg)
![DSC_0870](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0870.jpg)
The display will change between 3 values: Input voltage, output voltage and output current.
Measurements
- Usb output is coded as usb charger (DCP).
- The two usb outputs are in parallel.
- Power consumption when idle is 18mA from 12V and 13mA from 24V
- Display will flash at 10.7 volt or lower input voltage.
- Display turns off at about 6.8 volt
- Weight: 20.7g
- Length: 64.5mm
- Front: 35.2 x 25.2mm
![CurrentMeter](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/CurrentMeter.png)
Both voltmeter and current meter have a good precision.
![Load%20sweep%2011.6V%20Bottom](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/Load%20sweep%2011.6V%20Bottom.png)
The charger has a over current protection a bit about 2.3A, this is fine for a 2.1A rated charger.
![Load%20sweep%2011.6V%20Top](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/Load%20sweep%2011.6V%20Top.png)
The over current limit is the same on both outputs
![Load%20sweep%2011.6V](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/Load%20sweep%2011.6V.png)
Because they are in parallel and the maximum output current is about 2.3A
![Load%20sweep%2024.0V](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/Load%20sweep%2024.0V.png)
At 24V the over current protection do not looks as good, it trips at the same current but do not drop the voltage as fast.
![No%20load%20voltage%20sweep](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/No%20load%20voltage%20sweep.png)
The unloaded current drops a bit up and down, due to the display changing between the different values.
![Voltage%20sweep%202.0A%20input%20current](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/Voltage%20sweep%202.0A%20input%20current.png)
![Voltage%20sweep%202.0A](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/Voltage%20sweep%202.0A.png)
Even at 2A load the output can be maintained down to 7V
![Load%20test%202.1A](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/Load%20test%202.1A.png)
There was no problem running 1 hour with full load.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.
![Temp5683](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/Temp5683.png)
M1: 43.1°C, HS1: 53.8°C
![Temp5684](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/Temp5684.png)
M1: 55.3°C, HS1: 57.2°C
![10ohm](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/10ohm.png)
At 0.5A the noise is 11mV rms and 161mVpp
![5ohm](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/5ohm.png)
At 1A the noise is 11mV rms and 142mVpp
![2.5ohm](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/2.5ohm.png)
At 2A the noise is 25mV rms and 175mVpp
Tear down
![DSC_0871](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0871.jpg)
I could break the lid of the charger, the display and usb connectors was then loose and could be pulled out, to get the switcher board I had to press on the sides and use a pin to push from the bottom.
![DSC_0872](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0872.jpg)
There is space for a fuse at the 12V input, but it is just a 0.05ohm resistor. There is 3 wires to the display board: 0V, 5V and Input (For voltmeter)
![DSC_0882](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0882.jpg)
Below the inductor is switcher (U1: DP3115 2.5A synchronous buck switcher).
![DSC_0873](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0873.jpg)
This side do not contain any parts.
![DSC_0878](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0878.jpg)
![DSC_0879](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0879.jpg)
![DSC_0883](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0883.jpg)
![DSC_0880](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0880.jpg)
![DSC_0881](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0881.jpg)
![DSC_0874](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0874.jpg)
On this side is the display and the two usb connectors, below the display is a few resistors and capacitor. Two of the resistors are probably a voltage divider for input voltage.
![DSC_0875](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0875.jpg)
This side has the display controller (U3) and a current shunt (R10 & R14: 30mOhm & 500mOhm) to measure the output current.
The display mist have a build-in chip, with only 6 pins it is not possible to control it directly.
![DSC_0877](https://lygte-info.dk/pic/USB%20from%2012V/24%20Olaf%20Dual%20Car%20charge%20with%20display%202.1A/DSC_0877.jpg)
Being a 12V device there is no need to test with high voltages.
Conclusion
I am not impressed with the specification on the dealer site, but the charger works fine, has a good coding, is overload protected at a good level and the display is nice. Only problem is that the current is fine for one usb connector it is way to low for two connectors.
I will rate it as fairly good.
Notes
Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger