From six different power supply models from Huntkey we tested to date, five of them couldn’t deliver their labeled wattage, literally exploding (we posted the videos of the explosions on YouTube). They offered us money to take the reviews down and also started a campaign to make other manufacturers to boycott us, which actually backfired on them. You can read the whole story here. We got our hands on a model from a series we haven’t reviewed yet, Balance King, so we were really curious to see if this model would work fine or would also explode like its sisters. Check it out.
Figure 1: Huntkey Balance King 4500 450 W power supply.
Figure 2: Huntkey Balance King 4500 450 W power supply.
Huntkey Balance King 4500 450 W is 5 ½” (140 mm) deep, using a 120 mm fan on its bottom. It doesn’t have any PFC circuit, being based on the obsolete half-bridge topology.
No modular cabling system is available and only the main motherboard cable has a nylon protection, that doesn’t come from inside the unit. Most wires are 18 AWG, which is the minimum recommended gauge, but the wires used with the SATA and peripheral power connectors are 20 AWG, i.e., thinner than the recommended. The cables included are:
- Main motherboard cable with a 20/24-pin connector, 19 ¾” (50 cm) long.
- One cable with two ATX12V connectors that together form one EPS12V connector, 20 ½” (52 cm) long (permanently attached to the power supply).
- One cable with two six/eight-pin connector for video cards, 19 ¾” (50 cm) to the first connector and 5 7/8” (15 cm) between connectors.
- One cable with two SATA power connectors and one standard peripheral power connector, 19 ¾” (50 cm) to the first connector and 5 7/8” (15 cm) between connectors.
- One cable with two SATA power connectors, one standard peripheral power connector and one floppy disk drive power connector, 19 ¾” (50 cm) to the first connector and 5 7/8” (15 cm) between connectors.
The number of connectors is satisfactory for a 450 W product, although we’d prefer if the manufacturer had separated the two video card power connectors in independent cables, and also the SATA and peripheral power connectors we think should be installed on separated cables.
Figure 3: Cables.
Now let’s take an in-depth look inside this power supply.
We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our Anatomy of Switching Power Supplies tutorial to understand how a power supply works and to compare this power supply to others.
This page will be an overview, and then in the following pages we will discuss in detail the quality and ratings of the components used. The first thing we wanted to check was whether this unit was based on the same design as other Huntkey power supplies we’ve tested to date. The answer was negative: Balance King 4500 uses a different internal design from Green Star, V-Power and Titan series.
Figure 4: Overall look.
Figure 5: Overall look.
Figure 6: Overall look.
As we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil.
This power supply is flawless on this stage, providing all the required components, including the MOV’s.
Figure 7: Transient filtering stage (part 1).
Figure 8: Transient filtering stage (part 2).
In the next page we will have a more detailed discussion about the components used in the Huntkey Balance King 4500.
On this page we will take an in-depth look at the primary stage of Huntkey Balance King 4500. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.
This power supply uses one T15XB80 rectifying bridge, which supports up to 15 A at 100° C if a heatsink is used – which is not the case – but only 3.2 A at 25° C if a heatsink isn’t used. The difference is outrageous and Huntkey should have added a heatsink to this component. At 115 V this unit would be able to pull up to 368 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 294 W without burning itself out. Of course we are only talking about this component and the real limit will depend on all other components from the power supply. This is the same component used on Huntkey Green Star 350 W, Huntkey Green Star 450 W, Huntkey Green Star 550 W, Huntkey V-Power 550 W and Huntkey Titan 650 W (but at least on this last model the manufacturer added a heatsink).
Figure 9: Rectifying bridge.
Balance King 4500 uses two 2SC3320 power NPN transistors on its switching section using the obsolete half-bridge design, supporting up to 15 A at 25° C (unfortunately the manufacturer from these transistors do not say how much they can deliver at higher temperatures). These are the same transistors used on Green Star 550 W, V-Power 550 W and Titan 650 W (Rocketfish 700 W) from Huntkey. These transistors are more “powerful” than the ones used on the 350 W, 400 W and 450 W versions from Green Star power supplies.
Figure 10: Switching transistors.
The primary is controlled by a KA7500B PWM controller, which is physically installed on the secondary.
Figure 11: PWM controller.
Now let’s take a look at the secondary of this power supply.
Huntkey Balance King 4500 has six Schottky rectifiers on its secondary.
Since this power supply uses a half-bridge configuration to calculate the maximum theoretical current each output can deliver is easy: all we need to do is to add the maximum current supported by all diodes.
The +12 V output is produced by two STPS20S100CT Schottky rectifiers connected in parallel, each one supporting up to 20 A (10 A per internal diode at 150° C, 0.71 V maximum voltage drop). This gives us a maximum theoretical current of 40 A or 480 W for the +12 V output.
The +5 V output is produced by two STPS3045CT Schottky rectifiers connected in parallel, each one capable of delivering up to 30 A (15 A per internal diode at 155° C, 0.57 V maximum voltage drop), giving us a maximum theoretical current of 60 A or 300 W for the +5 V output.
The +3.3 V output is produced by another two STPS3045CT Schottky rectifiers, giving us a maximum theoretical current of 60 A or 198 W for the +3.3 V output.
The secondary was improved in comparison with Green Star 450 W, Green Star 550 W and V-Power 550 W models: all these models use the same rectifiers for the +12 V output, but have a lower limit of 30 A/150 W (Green Star 450 W) or 40 A/200 W (550 W models) on +5 V output and 30 A/99 W (Green Star 450 W) or 40 A/132 W (550 W models) on +3.3 V output.
All these numbers are theoretical. The real amount of current/power each output can deliver is limited by other components, especially by the coils used on each output.
Figure 12: +3.3 V, +5 V and +12 V rectifiers.
The monitoring circuit is built using two LM339 integrated circuits (each one has four voltage comparators inside).
Figure 13: Monitoring circuit.
The capacitors from the voltage doubler are from Teapo and the capacitors from the secondary are from Teapo and Fcon.
In Figure 14, you can see the power supply label containing all the power specs.
Figure 14: Power supply label.
This power supply has two +12 V rails (the monitoring integrated circuit really provides monitoring for two +12 V channels and we could clearly see the two current sensors installed on the printed circuit board), distributed like this:
- +12V1 (solid yellow wire): All cables but the ATX12V/EPS12V.
- +12V2 (yellow with black stripe wire): ATX12V/EPS12V cable.
This distribution is perfect, as it put the CPU and the video card on separated rails, being the typical distribution on power supplies with two rails.
Now let’s see if this power supply can really deliver 450 W.
We conducted several tests with this power supply, as described in the article Hardware Secrets Power Supply Test Methodology.
Since we didn’t know beforehand if this power supply would be able to deliver its labeled power, we decided to test it differently from our usual procedure. We tested it under several load scenarios, starting from 85 W, then moving to 100 W and then increasing power in 25 W steps until we reached the maximum the unit would be able to deliver.
If you add all the power listed for each test, you may find a different value than what is posted under “Total” below. Since each output can vary slightly (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. On the “Total” row we are using the real amount of power being delivered, as measured by our load tester.
The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test the +12VA input was connected to the power supply +12V1 rail, while the +12VB input was connected to the power supply +12V2
rail (EPS12V connector).
| Input | Test 1 | Test 2 | Test 3 | Test 4 |
| +12VA | 3 A (36 W) | 3.5 A (42 W) | 4.5 A (54 W) | 5.5 A (66 W) |
| +12VB | 2.5 A (30 W) | 3.25 A (39 W) | 4 A (48 W) | 5 A (60 W) |
| +5V | 1 A (5 W) | 1 A (5 W) | 1.5 A (7.5 W) | 1.5 A (7.5 W) |
| +3.3 V | 1 A (5 W) | 1 A (5 W) | 1.5 A (4.95 W) | 1.5 A (4.95 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 85.7 W | 100.6 W | 125.9 W | 149.6 W |
| % Max Load | 19.0% | 22.4% | 28.0% | 33.2% |
| Room Temp. | 34.2° C | 34.9° C | 35.3° C | 35.8° C |
| PSU Temp. | 35.5° C | 36.4° C | 37.1° C | 37.6° C |
| Voltage Regulation | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass |
| AC Power | 110.1 W | 127.7 W | 157.0 W | 185.5 W |
| Efficiency | 77.8% | 78.8% | 80.2% | 80.6% |
| AC Voltage | 115.2 V | 114.7 V | 114.7 V | 114.4 V |
| Power Factor | 0.589 | 0.600 | 0.618 | 0.631 |
| Final Result | Pass | Pass | Pass | Pass |
| Input | Test 5 | Test 6 | Test 7 | Test 8 |
| +12VA | 6.25 A (75 W) | 7.5 A (90 W) | 8.25 A (99 W) | 9.25 A (111 W) |
| +12VB | 6 A (72 W) | 7 A (84 W) | 8 A (96 W) | 9 A (108 W) |
| +5V | 2 A (10 W) | 2 A (10 W) | 2.5 A (12.5 W) | 2.5 A (12.5 W) |
| +3.3 V | 2 A (6.6 W) | 2 A (6.6 W) | 2.5 A (8.25 W) | 2.5 A (8.25 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 174.7 W | 201.0 W | 226.0 W | 248.6 W |
| % Max Load | 38.8% | 44.7% | 50.2% | 55.2% |
| Room Temp. | 39.2° C | 38.9° C | 40.0° C | 38.8° C |
| PSU Temp. | 38.5° C | 39.5° C | 40.7° C | 41.2° C |
| Voltage Regulation | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass |
| AC Power | 216.2 W | 248.3 W | 279.2 W | 308.5 W |
| Efficiency | 80.8% | 81.0% | 80.9% | 80.6% |
| AC Voltage | 113.9 V | 112.7 V | 112.7 V | 111.9 V |
| Power Factor | 0.642 | 0.654 | 0.659 | 0.671 |
| Final Result | Pass | Pass | Pass | Pass |
| Input | Test 9 | Test 10 | Test 11 | Test 12 |
| +12VA | 10 A (120 W) | 11 A (132 W) | 12 A (144 W) | 13 A (156 W) |
| +12VB | 10 A (120 W) | 11 A (132 W) | 11.75 A (141 W) | 12.75 A (153 W) |
| +5V | 3 A (15 W) | 3 A (15 W) | 3.5 A (17.5 W) | 3.5 A (17.5 W) |
| +3.3 V | 3 A (9.9 W) | 3 A (9.9 W) | 3.5 A (11.55 W) | 3.5 A (11.55 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 273.8 W | 296.7 W | 321.2 W | 343.6 W |
| % Max Load | 60.8% | 65.9% | 71.4% | 76.4% |
| Room Temp. | 40.3° C | 41.9° C | 40.6° C | 42.7° C |
| PSU Temp. | 42.6° C | 44.7° C | 44.8° C | 46.3° C |
| Voltage Regulation | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass |
| AC Power | 341.6 W | 371.6 W | 407.4 W | 440.0 W |
| Efficiency | 80.2% | 79.8% | 78.8% | 78.1% |
| AC Voltage | 112.6 V | 112.2 V | 111.9 V | 111.2 V |
| Power Factor | 0.673 | 0.678 | 0.682 | 0.688 |
| Final Result | Pass | Pass | Pass | Pass |
| Input | Test 13 | Test 14 | Test 15 | Test 16 |
| +12VA | 14 A (168 W) | 15 A (180 W) | 16 A (192 W) | 17 A (204 W) |
| +12VB | 13.5 A (162 W) | 14.5 A (174 W) | 15.5 A (186 W) | 16.5 A (198 W) |
| +5V | 4 A (20 W) | 4 A (20 W) | 4.5 A (22.5 W) | 4.5 A (22.5 W) |
| +3.3 V | 4 A (13.2 W) | 4 A (13.2 W) | 4.5 A (14.85 W) | 4.5 A (14.85 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 367.8 W | 389.7 W | 414.9 W | 443.6 W |
| % Max Load | 81.7% | 86.6% | 92.2% | 98.6% |
| Room Temp. | 44.2° C | 46.4° C | 48.0° C | 49.3° C |
| PSU Temp. | 48.0° C | 50.8° C | 53.0° C | 55.6° C |
| Voltage Regulation | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass |
| AC Power | 476.0 W | 512.0 W | 557.0 W | 641.0 W |
| Efficiency | 77.3% | 76.1% | 74.5% | 69.2% |
| AC Voltage | 110.8 V | 110.5 V | 109.9 V | 109.6 V |
| Power Factor | 0.694 | 0.701 | 0.705 | 0.717 |
| Final Result | Pass | Pass | Pass | Pass |
It is important to note that we were very generous with temperatures, because we started testing this unit at 85 W, a load that doesn’t produce a lot of heat inside our thermal chamber. We didn’t want to heat our thermal chamber with the power supply running at a higher load because we didn’t know beforehand if the power supply would be able to deliver any higher load. Therefore we decided to play on the safe side.
Huntkey Balance King 4500 achieved a performance above we of what we were expecting: all voltages were within 3% their nominal voltages on all tests except on tests 15 (where the -12 V output got out this tighter range) and 16 (where -12 V and +12 V outputs got out this tighter range), but still inside the correct range (5% for all positive voltages and 10% for -12 V) – translation: voltages closer to their nominal value
s than required, which is terrific –, and noise and ripple was always low, which is obviously desirable. During test 16 noise level at +12VA was 31.2 mV, at +12VB was at 31.4 mV, at +5 V was at 17.6 mV and at +3.3 V was 10.4 mV (the maximum allowed is 120 mV on 12 V outputs and 50 mV on +5 V and +3.3 V outputs).
Efficiency was above 80% when we pulled between 125 W and 275 W, which isn’t bad at all for a low-end power supply based on the half-bridge topology. On all other tests we saw efficiency between 75% and 80%, except on test 16, where efficiency was at 69.2%. Usually when efficiency drops sharply like it happens from test 15 to test 16, it means that the unit has already passed its adequate operating point. Therefore if we were the ones labeling this unit, we would prefer labeling it as a 420 W or even 400 W unit.
This is better supported by what happened during test 16, with the power supply delivering 450 W. We will explain this in details in the next page.
Right after we collected all data during test 16, the power supply burned, burning the fuses from our load tester. On the video below you can see the whole test 16 in action. Notice how at the end the power supply burns and our load tester “resets,” which indicates that its fuses had just been blown.
After replacing the fuses, we tried to turn the power supply back on, configuring our load tester with a lower load. We always do this when fuses blow, because sometimes the power supply is still working fine. As soon as we hit the “on” button from our load tester the unit exploded really hard. Unfortunately our camera was turned off during this moment. After opening the power supply we could see that the switching transistors were the components that exploded. Also, one of the electrolytic capacitors was swollen (see Figure 18), ready to leak and/or explode. On the pictures below you can see the evidence.
Figure 15: Switching transistors exploded.
Figure 16: Evidence of the explosion.
Figure 17: Evidence of the explosion.
Figure 18: Electrolytic capacitor almost exploding.
Huntkey Balance King 4500 power supply specs include:
- ATX12V 2.2
- Nominal labeled power: 450 W.
- Measured maximum power: 450 W at 49.3° C (exploded after a few minutes).
- Labeled efficiency: 70% minimum at 230 V at full load
- Measured efficiency: Between 69.2% and 81.0% at 115 V (nominal, see complete results for actual voltage).
- Active PFC: No.
- Modular Cabling System: No.
- Motherboard Power Connectors: One 20/24-pin connector and two ATX12V connectors that together form an EPS12V connector.
- Video Card Power Connectors: Two six/eight-pin connectors sharing the same cable.
- SATA Power Connectors: Four in two cables.
- Peripheral Power Connectors: Two in two cables.
- Floppy Disk Drive Power Connectors: One.
- Protections: Information not available.
- Warranty: Two years.
- More Information: https://www.huntkeydiy.com
- Average price in the US: We couldn’t find this product being sold in the USA.
Huntkey Balance King 4500 performed better than its sisters from Green Star and V-Power series. The highlights from this power supply include an exceptional voltage regulation for a low-end product (all voltages were within 3% their nominal voltages on all tests except on our 425 W and 450 W tests – translation: voltages closer to their “face value” than required) and very low noise and ripple levels. In summary, it doesn’t offer any risk to your components.
Efficiency was above 80% when we pulled between 125 W and 275 W, which isn’t bad at all for a low-end power supply based on the half-bridge topology. On all other tests we saw efficiency between 75% and 80%, except on our 450 W test, where efficiency was at 69.2%.
However, after a few minutes working at 450 W the power supply exploded. So it can deliver its labeled power for only a few minutes. Therefore if we were the ones labeling this unit, we would prefer labeling it as a 420 W or even as a 400 W unit.
So the only real problem with this unit is its inability of delivering 450 W continuously. If you are going to build a PC that will pull between 125 W and 275 W.
But frankly if you are really on budget you are better off buying an OCZ StealthXStream 400 W, which costs around the same, provides a way higher efficiency, won’t explode if you try to pull its labeled wattage continuously (and we could easily pull 450 W from this OCZ unit) and shuts down if you try to pull more than it can deliver.
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