The Nekteck NK-TC-PD30 51W Dual Port USB Type-C PD Wall Charger is one of the many chargers sold by Nekteck which also includes the Nekteck 46W USB-C Wall Charger, Nekteck 65W USB-C Power Delivery Wall Charger and Nekteck 72W USB Type-C PD Charger Station. The Nekteck NK-TC-PD30 51W Dual Port USB Type-C PD Wall Charger comes with each a 39 watts based USB Type-C and a 12 watts based USB Type-A charging output, which is also similar to the Monoprice PD52U-2UT01 39W Dual USB Wall Charger and the Choetech PD51-1C1U 51W Dual Port USB Type-C PD Wall Charger.

By supporting 15 watts (5 volts @ 3 amps), 27 watts (9 volts @ 3 amps) and 39 watts (15 volts @ 2.6 amps) over USB Type-C, the Nekteck NK-TC-PD30 51W Dual Port USB Type-C PD Wall Charger allows you to charge most notebook PC's in the market as well as tablets and phones. Even though the charger shows that it has been certified by the USB-IF through the USB certification logo, it fails many USB compliance tests (see more details at the bottom of this review) so be extra careful when using this charger. Note that the same problem was also seen with the Monoprice PD52U-2UT01 39W Dual USB Wall Charger (in this review) and the Choetech PD51-1C1U 51W Dual Port USB Type-C PD Wall Charger (see this review).

Note that while the Nekteck NK-TC-PD30 51W Dual Port USB Type-C PD Wall Charger supports USB Power Delivery based charging, it can also support Qualcomm Quick Charge technology to charge Qualcomm Quick Charge enabled phones (click here to see how we tested this charger with the Xiaomi Mi 5 phone).

The packaging also includes a separate USB Type-C to Type-C cable accessory which doesn't require using your own cable with the charger.

The charger has two standard foldable prongs to plug into a AC wall outlet for charging.

If compared side by side, the Nekteck NK-TC-PD30 51W Dual Port USB Type-C PD Wall Charger has a design that is very similar to the Monoprice PD52U-2UT01 39W Dual USB Wall Charger and the Choetech PD51-1C1U 51W Dual Port USB Type-C PD Wall Charger. Like both these two other chargers, the Nekteck USB Type-C port also supports Qualcomm Quick Charge technology besides USB Power Delivery for charging (click here to see more).

You can connect your phone or tablet to the USB Type-A port for 12 watts (5 volts @ 2.4 amps) of legacy charging.

Using the USB Power Test App from Granite River Labs with the Granite River Labs USB Power Delivery Compliance C2 Tester, we generate the following test results for the Nekteck NK-TC-PD30 51W Dual Port USB Type-C PD Wall Charger. Note the charger stopped working after running through these tests.

The USB Power Test App first negotiates a power contract for every PDO supported by the Nekteck charger, and increases the load gradually to find the threshold where over current protection (OCP) kicks in and voltage and current starts to drop for safety reasons.

The USB Power Test App reports out all the PDO's supported by the Nekteck charger and their OCP thresholds. Here it shows an additional 36 watts (12 volts @ 3 amps) PDO which the charger also supports but is not listed in the charger's specs. OCP thresholds for the charger are set at about 13-20% above the maximum current levels for the fixed PDO's.

PDO	OCP (A)
PDO#1 Fixed: 5V 3A	3.64
PDO#2 Fixed: 9V 3A	3.58
PDO#3 Fixed: 12V 3A	3.41
PDO#4 Fixed: 15V 2.6A	3.19

The USB Power Test App from Granite River Labs also produces an I-V curve which graphically shows the relationship between voltage and current for each PDO. Except for the 12V 3A PDO, we can observe current fold-back behavior for the other PDO's where as the current increases beyond the OCP threshold, the voltage starts to curve down rather than immediately shutting off. The 12V 3A PDO shows the voltage immediately shuts off when crossing the OCP threshold.

Since the Nekteck NK-TC-PD30 51W Dual Port USB Type-C PD Wall Charger is a multi port charger, the USB Power Test App can be used to determine whether each output port of the charger is able to supply power independently. For every PDO supported by the Nekteck charger, the USB Power Test App increases the load gradually for both the USB Type-C and Type-A ports to detect any power loss at the highest load limit for each port.

USB Type-C Port

USB Type-A Port

The USB Power Test App reports out the voltage, current and load limits for all the PDO's supported by the Nekteck charger for each port.

Port1 PDO	Port2 PDO	Port1 (V)	Port1 (A)	Port1 Loading(%)	Port2 (V)	Port2 (A)	Port2 Loading(%)
PDO#1 Fixed: 5V 1.5A		4.92	1.49	100% (7.3W)
PDO#1 Fixed: 5V 1.5A	PDO#1 Fixed: 5V 3A	4.92	1.49	100.24%	4.83	2.96
PDO#1 Fixed: 5V 1.5A	PDO#2 Fixed: 9V 3A	4.92	1.49	100.38%	8.76	2.97
PDO#1 Fixed: 5V 1.5A	PDO#3 Fixed: 12V 3A	4.92	1.49	100.38%	11.68	2.97
PDO#1 Fixed: 5V 1.5A	PDO#4 Fixed: 15V 2.6A	4.92	1.49	100.38%	14.68	2.59
	PDO#1 Fixed: 5V 3A				4.83	2.96	100% (14.3W)
PDO#1 Fixed: 5V 1.5A	PDO#1 Fixed: 5V 3A	4.92	1.49		4.83	2.96	100.24%
	PDO#2 Fixed: 9V 3A				8.76	2.96	100% (26W)
PDO#1 Fixed: 5V 1.5A	PDO#2 Fixed: 9V 3A	4.92	1.49		8.76	2.97	100.36%
	PDO#3 Fixed: 12V 3A				11.68	2.97	100% (34.7W)
PDO#1 Fixed: 5V 1.5A	PDO#3 Fixed: 12V 3A	4.92	1.49		11.68	2.97	100%
	PDO#4 Fixed: 15V 2.6A				14.67	2.59	100% (38W)
PDO#1 Fixed: 5V 1.5A	PDO#4 Fixed: 15V 2.6A	4.92	1.49		14.68	2.59	100.18%

The USB Power Test App can also use the Granite River Labs USB Power Delivery Compliance C2 Tester integrated with the GW Instek APS-7100 programmable AC power supply to compare the charger's power output vs power input so that power efficiency can be measured and compared to regulatory limits from United States of Energy (DOE) Level VI or European Union's CoC Tier 2 requirements. We can repeat the power efficiency tests for different PDO's, current load conditions, and different AC input ranges, allowing us to get a complete picture of power efficiency ranges across all different usage scenarios.

Using the USB Power Delivery Compliance C2 Tester from Granite River Labs to run just a subset of the full USB Power Delivery compliance test suite, compliance failures were mostly observed for the Nekteck NK-TC-PD30 51W Dual Port USB Type-C PD Wall Charger even though the charger shows it is USB-IF certified so it would be better to take precautions when using this charger.

USB-IF High Level Mapping Summary

Sl No	Test Category	Test Group Description	Test Result
1	PHY_PRIMARY_TX	BMC Physical Layer Transmitter	FAIL
2	PHY_PRIMARY_RX	BMC Physical Layer Receiver	FAIL
3	PHY_PRIMARY_MISC	BMC Physical Layer Miscellaneous	FAIL
4	PROT_PRIMARY	Protocol Specific Primary	FAIL
5	POWER_PRIMARY	Power Source/Sink Primary	FAIL

Result Summary

Sl No	Test ID	Test Name	Test Result
2	TDA.2.1.1.2	TDA.2.1.1.2 BMC PHY TX BIT	FAIL
3	TDA.2.1.2.2	TDA.2.1.2.2 BMC PHY RX INT REJ	PASS
4	TDA.2.1.2.1	TDA.2.1.2.1 BMC PHY RX BUSIDL	FAIL
5	TDA.2.1.3.1	TDA.2.1.3.1 BMC PHY TERM	FAIL
6	TDA.2.1.3.2	TDA.2.1.3.2 BMC PHY MSG	FAIL
7	TDA.2.2.1	TDA.2.2.1 BMC PROT SEQ GETCAPS	FAIL
8	TDA.2.2.3	TDA.2.2.3 BMC PROT SEQ DRSWAP	FAIL
9	TDA.2.2.4	TDA.2.2.4 BMC PROT SEQ VCSWAP DFP	FAIL
10	TDA.2.2.6	TDA.2.2.6 BMC PROT SEQ PRSWAP	FAIL
11	TDA.2.2.7	TDA.2.2.7 BMC PROT BIST NOT 5V SRC	FAIL
12	TDA.2.2.8	TDA.2.2.8 BMC PROT REV NUM	FAIL
13	TDA.2.2.9	TDA.2.2.9 BMC PROT GSC REC	FAIL
15	TDA.2.3.2.1	TDA.2.3.2.1 POW SRC TRANS P PC	FAIL