STABILIST 65W Teardown: A Highly Efficient Charger That Still Runs Too Hot
イチケン / ICHIKEN
In this video, electronics YouTuber Ichiken reviews and takes apart the STABILIST 65W, a single-port USB charger from a little-known brand sold on Amazon. The question is whether a charger with excellent conversion efficiency also stays cool under load. The reviewer's answer is no. The charger's efficiency places it among the top performers for its price, but its thermal design lets some areas get too hot during sustained full-power use. That limits which buyers the reviewer would recommend it to.
Why This Charger Was Chosen
The reviewer found the STABILIST while browsing Amazon for interesting USB chargers. It had fairly good reviews and a price the reviewer called reasonably affordable rather than extremely cheap. The product page also promised a lot, including the claim that it was the smallest and lightest charger in its class. That combination made the reviewer want to buy one and open it up.
Externally, it is a typical single-port 65W charger with a foldable plug. The reviewer compared it side by side with the best-selling Anker Nano II 65W to show its size. They also pointed out that the "smallest and lightest" claim dates from the product's launch, around April 2024. As of 2026, the reviewer says the smallest 65W single-port chargers are CIO's NovaPort SOLO II 65W and the UGREEN Nexode Air 65W.
Who Actually Makes It
The back of the charger lists what appears to be a Chinese manufacturer's name in English. The reviewer looked it up and found that it is a factory producing chargers and USB cables, and believes it is the contract manufacturer. The reviewer notes that this is common for USB chargers. Brands often put their own label on ready-made products from a factory and sell them outside China, a practice generally called ODM.
The reviewer could not determine how much the STABILIST brand itself does, such as whether it is involved in planning or design. However, the product page says TDK components are used, and the reviewer takes that as a sign the brand may have specified at least some of the parts.
Output Specifications
The charger supports USB PD and PPS. Its maximum PPS current is 3.25 A, and the reviewer notes that some chargers on the market can deliver 5 A over PPS.
Power Conversion Efficiency
The reviewer treats conversion efficiency as a key metric. It measures how much of the AC power drawn from the outlet ends up as usable DC power at the USB port. Higher efficiency means less power is lost inside the charger, so it should generate less heat. Most users never think about this number, but the reviewer stresses that it directly affects how small a charger can be made.
The measured efficiency curve, with output power on the horizontal axis, was high across the whole power range, which the reviewer says is typical of modern USB chargers. Peak efficiency was 92.3% at 20 V output. The reviewer uses these rough benchmarks for a 65W-class charger:
- above 91% is pretty good
- above 92% is "quite good"
The STABILIST also stayed above 90% efficiency at low output power. The reviewer calls this unusual, since few chargers stay efficient at light loads. The reviewer also tested with a 200 V outlet voltage and measured a maximum efficiency of 93.1%. Based on these numbers, the reviewer judged that for a charger costing 2,980 yen, its efficiency ranks near the top.
Heat Under Full Load: 93°C at the USB Port
Given the strong efficiency results, the reviewer expected good thermal results too. Instead, the thermal results were disappointing.
After 90 minutes of continuous operation at the full 65W, the thermal camera showed the hottest spot on the side with the USB port, at 93°C. The other surfaces were in the 70s. The reviewer considers 93°C on the connector face clearly too high. Temperatures in the 70s, by contrast, are normal for current USB chargers.
The reviewer also pointed to the large temperature differences across the case. To them, this suggests the charger is not spreading its internal heat evenly to the enclosure surface. The reviewer explained why that matters. In a small charger like this, roughly 60–70% of heat leaves through natural convection from the surface, and the remaining 30–40% leaves through radiation. Surface temperature should obviously be kept in check, but the reviewer says it is better to bring the whole surface close to the upper limit allowed by contact temperature standards. A hot, evenly heated surface makes effective use of radiative cooling. The reviewer added that the thermally conductive filler inside chargers is fairly expensive, and has heard that manufacturers sometimes adjust how much they use to control cost.
Half Load Is a Different Story
At 50% load (32W) of continuous operation, the maximum surface temperature was 55°C. The reviewer notes that chargers rarely run at full power for long in real use. For example, when charging their own laptop, the power output usually drops once the battery fills. At 32W, the reviewer considers this temperature fine.
No Thermal Throttling Observed
The reviewer also attached a thermocouple to the USB-port side, the hottest area, and logged temperature under a continuous 65W load. The temperature started rising immediately, leveled off about 60 minutes in, and peaked at 91°C.
At that temperature, the reviewer would want the charger to throttle its output. In their test setup, it never did. Monitoring the charger's PDOs during the full-load test showed that it never asked the connected device to draw less power. According to the reviewer, it appears to keep supplying whatever is requested, regardless of internal temperature or operating conditions. The reviewer tried various experiments but could not confirm any thermal throttling behavior. They suspect that if the charger stops from genuine overheating, the cause is over-temperature protection inside the power supply ICs, not a deliberate reduction in output.
Inside: A Surprisingly Elaborate Metal Enclosure
Opening the case revealed an internal assembly wrapped almost entirely in metal plates. Because this is a lower-priced 65W charger, the reviewer had expected a simpler interior, and remarked that this design looks like it cost a fair amount. A metal plate like this can also shield radiated noise. In this case, though, the reviewer thinks its main purpose is heat dissipation: it collects heat from internal sources and passes it on to the housing.
A blue thermally conductive material sits between the circuitry and the metal plate. It fills the gaps created by uneven component heights so heat transfers efficiently. The front section, however, has no metal plate. That is where the transformer sits, right next to the USB port, the hottest spot in the thermal images. That area also has no thermal material. The reviewer concludes that the transformer's heat was reaching the surface directly, which explains the 93°C reading.
After removing the metal plate, the reviewer showed that the thermal sheet is quite thick. They described the overall approach this way: components are packed very tightly to keep the charger compact, and they are bonded together with thermally conductive silicone rubber. This thermally couples the parts and aims for a more uniform temperature distribution.
An Electrolytic Capacitor Glued to the Transformer
One detail concerned the reviewer. An electrolytic capacitor's explosion-proof vent is covered by thermally conductive silicone rubber. The reviewer said USB chargers sometimes feel like "anything goes" and that they occasionally see designs like this. The capacitor also sits right next to the transformer, one of the hottest components. After removing the transformer, the reviewer showed that the two are thermally bonded with silicone rubber.
At the full 65W, the transformer's surface exceeded 90°C, and the reviewer estimates the transformer itself runs around 100°C. With an electrolytic capacitor right beside it, the reviewer believes the charger's lifespan will certainly be shorter if it is used to charge and power a laptop at full capacity.
The reviewer also offered a possible rationale for the layout. An aluminum electrolytic capacitor conducts heat well, so the designers may be using it to help spread heat through the charger. If the charger mostly handles phone charging at around 30W or less, the reviewer doesn't think the temperature rise is a concern for lifespan. They also speculated that because many people replace chargers after three or four years, the designers may not have planned for long-term use. Either way, the reviewer's advice is to avoid continuous use at the full 65W.
The Chips: A SOUTHCHIP Reference Design
All the key ICs are from SOUTHCHIP:
- an all-in-one SC3057 for the primary-side power semiconductor section
- an SC3503 as the secondary-side drive IC
- an SC2151A as the USB PD controller
The reviewer says the circuit is essentially SOUTHCHIP's flyback converter reference design, used as-is. In the reviewer's view, SOUTHCHIP offering a complete circuit solution makes its chips very easy to adopt, which is why they are so common in chargers.
The reviewer mentioned that Japan's Renesas also offers primary-side flyback controllers and is working on secondary-side rectifier controllers and PD controllers, and that these appear in Belkin chargers. Still, seeing designs like this one left the reviewer thinking SOUTHCHIP is very strong, and they said they hope Renesas does well.
Verdict
The reviewer concludes that the STABILIST 65W is fine for short bursts at full 65W, but they do not recommend running it at full power for long periods. It suits use that stays around 50% load. The reviewer adds a caveat, though: if that is how you will use it, some 65W multi-port chargers sell in the upper 1,000-yen range. The STABILIST is worth considering if size is your priority. If it isn't, the reviewer says plenty of other options are available.
Hello. Today, I'd like to do a teardown review of this USB charger. It's a product called STABILIST, a USB charger from a brand that isn't very well-known.
As for how I came across this, I was browsing Amazon to see if I could find any interesting USB chargers. It has pretty good reviews, and I wouldn't go so far as to say the price is super cheap, but it's reasonably affordable. What's more, it's the smallest and lightest in its class. Since there were so many very appealing words lined up, I thought I needed to buy this and take it apart, so I got it.
To give you a little sneak peek at the results, although there are some areas where the temperature gets too high in the heat dissipation design, the basic performance of the charger is quite high. I think it could be a good value option depending on how you use it, so if you're interested, please be sure to watch until the end. But first, let me introduce today's sponsor.
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As for its appearance, it's a typical single-port 65W USB charger. The plug is foldable. Compared to the Anker Nano II 65W, another best-selling 65W-class charger, you can really get a sense of the size, can't you?
Although the Amazon product page says it's the smallest and lightest in its class, this was when that product was released. Please note that this data is from around April 2024. In fact, as of 2026, the smallest USB chargers in the 65W single-port class are CIO's NovaPort SOLO II 65W and the UGREEN Nexode Air 65W.
On the back of the product, it says something that looks like the name of a Chinese manufacturer in English. When I looked into it, I found out it was a factory that makes chargers and USB cables. I believe this factory is the one contracted to handle manufacturing.
This is common with USB chargers: attaching a brand label to ready-made products sold at the factory and selling them in markets outside of China. It's what's commonly referred to as ODM, among other things. I'm not sure to what extent the manufacturer of this product handles things on its own or is involved in planning or design, but while browsing the product page, I saw that it says TDK components are used. They may have specified the parts to be used, among other things.
In terms of charging performance, it supports PD charging, and it also supports PPS. However, the maximum current is 3.25 A. After all, there are some chargers out there that can deliver 5 A via PPS from time to time.
Next is one of the key performance indicators: we measured the power conversion efficiency. This indicates how efficiently the USB charger can convert AC power from the outlet into DC power for USB charging. The more efficient a USB charger is, the more power loss within the charger is reduced, and as a result, less heat is generated. In fact, it's not something most people who use chargers really worry about, but since this efficiency—whether it's good or bad—affects the size of the charger itself, it's actually a pretty important metric.
Here are the results of the efficiency measurement. The horizontal axis represents output power, and the vertical axis represents power conversion efficiency. As is typical of USB chargers these days, it offers high efficiency across the entire power range. The maximum efficiency was 92.3% at 20 V. With a 65W-class USB charger, when efficiency exceeds 91%, performance is actually pretty good, and if it exceeds 92%, it falls into the "quite good" category.
Also, upon closer inspection, even in the range where the output power is low, the efficiency exceeds 90%. There actually aren't many USB chargers that are highly efficient even at low loads. It's a rare type.
While we were at it, we also measured the efficiency when the outlet voltage was 200 V. The maximum efficiency is 93.1%. It's pretty good. I'll also include the loss curve, so if you want to check, please pause the video. My overall impression is that, as a USB charger that you can buy for 2,980 yen, its performance is good enough to place it among the top ranks.
Since the efficiency measurements yielded quite good results, I had expected the temperature measurement results during charging to be quite good as well, but contrary to expectations, the results weren't very good.
First, here are the results of the thermography measurements. This is the temperature after 90 minutes of continuous operation at full power, 65W. The hottest part is the side with the USB port. The temperature is 93°C. On the other surfaces, the temperature was in the 70s. 93°C on the USB connector surface is clearly too high, but temperatures in the 70s on the other surfaces are common for modern USB chargers.
If you take a closer look at the temperature distribution measured by thermography, there are significant temperature variations. It feels like evenly dissipating internal heat to the surface of the enclosure isn't going well.
With a small USB charger like this, heat dissipation due to natural convection from the surface of the charger is about 60 or 70 percent, and the remaining 30% to 40% is heat dissipation through radiation. That's why, of course, it's best to avoid excessive surface temperatures, but pushing it right up to the upper limit specified in the contact temperature standards actually lets us make effective use of radiative cooling.
The heat-dissipating material inside the charger is actually pretty pricey, isn't it? Therefore, while keeping an eye on costs, I hear they sometimes adjust the amount of filler material used inside, among other things.
By the way, here is the temperature distribution when operating continuously at 32W under a 50% load. The highest temperature reached 55°C. In reality, regarding situations where you would use a USB charger at full power all the time, at least when I'm charging my laptop, once the battery is fully charged, power output often decreases after that. At 50% load, 32W, if the surface temperature is around this level, I think it's fine.
Next is the temperature measurement graph. This is a temperature measurement using a thermocouple on the side with the USB port, where the temperature is highest. While charging, it always draws power at the full 65W. The temperature began to rise immediately after the experiment started. About 60 minutes after the start, the temperature rise leveled off, and the maximum temperature reached 91°C. It's quite high.
When the temperature gets this high, as far as the charger's functionality is concerned, I'd like thermal throttling to kick in, but in this experimental setup, no thermal throttling occurred. By the way, when checking the charger's PDO during a 100% load test, it hadn't been sending requests to reduce the power supply to the sink. I think it's behaving as if it continues to supply the required power regardless of internal temperature or operating conditions.
I tried various experiments, but we were unable to verify the thermal throttling behavior. When the device stops working due to actual overheating, I think it might be shutting down due to overheating protection in the power supply ICs.
Okay, let's start taking it apart now. Here is the disassembled version. This is what I've extracted from where it used to fit snugly inside the case like this. When I looked inside the charger, I saw that it has a structure that looks like it's wrapped all the way around in metal plates like this.
Since it's in the lower price range for a 65W charger, I was thinking the interior might be designed to be a little simpler. It looks like it must have cost quite a bit. This metal plate may also provide shielding to block the radiated noise emitted by the USB charger, but in this case, it's probably there for heat dissipation. Heat is transferred from an internal heat source to the metal plate, and its role is to further transfer that heat to the surface of the housing.
I've briefly taken the contents apart for now. A blue heat-conductive material is sandwiched between the charger and the metal plate. This absorbs the unevenness of the parts and serves to efficiently transfer heat to the metal plate. The front section without a metal plate—this is a transformer. Near the USB port, where the temperature was highest as measured by thermography, no heat-conductive materials are included. Since a transformer is visible in this area, I suppose that means the heat from the transformer was being transferred directly.
From here, we'll break it down even further. The metal plate comes off. This is what the heat-conductive sheet actually looks like. It's pretty thick, isn't it? In terms of the basic design, the parts are arranged very closely together to make the device compact. And when it comes to heat, it's important to ensure a tight fit so that heat is transferred efficiently. While securing the parts together with thermally conductive silicone rubber, this design uses thermal coupling to ensure uniform temperature distribution.
There's an electrolytic capacitor in this section, but the pressure relief vent has been blocked by heat-conductive silicone rubber. When it comes to USB chargers, it really feels like anything goes. I occasionally see designs like this as well. Since there is an electrolytic capacitor right next to the transformer, which is a component that generates a lot of heat, the electrolytic capacitor probably doesn't last very long, does it?
When I removed the transformer as well, it was thermally coupled to an electrolytic capacitor using thermally conductive silicone rubber in this way. As for the transformer, if you use it at full power, 65W, the surface temperature exceeded 90°C. I think the temperature of the transformer itself is around 100°C. And since there's an electrolytic capacitor right next to it, when using a laptop that charges and supplies power at full capacity, the charger's lifespan will certainly be shorter.
On the other hand, since the interior of an electrolytic capacitor is made of aluminum, it conducts heat very well. Perhaps they're considering a design philosophy of using that thermal conductivity to transfer heat throughout the entire charger.
Without using it at full power, in cases like a smartphone where charging is limited to around 30W at most, the rise in temperature isn't really anything to worry about, so I don't think there's a problem in terms of lifespan. However, after using a charger like this for three or four years, I think I'll probably end up replacing it with a new charger soon. Perhaps they didn't anticipate such long-term use at the design stage. In any case, it seems like I should avoid continuous use at full power, 65W.
Next, we'll take a look at the IC chips used. Regarding the power semiconductor section on the primary side of the power supply, SOUTHCHIP's SC3057, an all-in-one type, is used. The secondary-side drive IC also used SOUTHCHIP's SC3503. The same applies to the USB PD controller: it uses the SOUTHCHIP SC2151A.
In terms of circuitry, this is the flyback converter reference circuit provided by SOUTHCHIP as is. After all, when it comes to making a charger, using SOUTHCHIP ICs is the way to go. A circuit is provided as a solution, and I guess it really is easy to use. Japan's Renesas also offers primary-side flyback controllers, secondary-side rectifier controllers, and PD controllers, and they are used in Belkin chargers. But when I see things like this, I can't help but think SOUTHCHIP is pretty strong, isn't it? I really hope Renesas, a Japanese manufacturer, does well.
So, I took apart and reviewed a USB charger I found on Amazon that looks like it offers good value for the price. Using the full 65W power for a short time is fine, but we do not recommend using it for long periods of time. I think it's well-suited for applications that involve prolonged use at 50% load.
But if that's the case, there are other 65W multi-port USB chargers available for purchase in the upper 1,000-yen range. If you're choosing based on size, it's definitely worth considering, but if you're not choosing based on size, there are plenty of other options available.
Links to purchase the USB charger we took apart for this review, as well as other recommended USB chargers, can be found in the description, so if there's something you're interested in, be sure to check it out. Thank you for watching the video all the way to the end.
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