What the advertised 37Wh are really worth
The Nexode 55W's rated 37Wh never fully reach the USB output. A detailed measurement puts the energy returned at 29.3 to 29.9Wh depending on the discharge rate, which places efficiency around 82%. A second, independent measurement, carried out with a different protocol, converges on a very close result, around 81%.
This figure places the Nexode 55W well above the market average for a power bank of this format, where 60 to 70% efficiency remains the norm.
Power held on a single port
On a single port used alone, the Nexode 55W lives up to its promise: an in-depth measurement records 54W in practice, very close to the 55W advertised. That maximum figure, however, is only reached with a smartphone compatible with Xiaomi's proprietary fast-charging protocol; for every other device, the real ceiling sits at 45W over standard USB PD, still a high output for this format.
The USB-A port, for its part, delivers 22.5W measured, a value higher than the one sometimes advertised in the commercial documentation, which counts in the product's favor rather than against it.
Simultaneous charging across multiple ports
As on other models in the same range, simultaneous charging of several devices is very limited: the manufacturer states itself, in its official documentation, that total output power drops to 15W as soon as two or three ports are used at the same time, regardless of the number of devices connected. An independent measurement records a slightly better result, around 20W combined, but the gap with the 54W available on a single port remains considerable.
Multi-port charging is therefore suited to small devices or a slow top-up, not to the fast simultaneous recharge of two demanding devices.
Recharging the battery: slower and less consistent than advertised
This is the most problematic point of the product. The official documentation mentions a full recharge in two hours with a suitable charger, but the input power actually measured caps around 34 to 35W, not 45W. A measurement carried out with a dedicated 100W charger achieves a full recharge in 1h32, at sustained power with no slowdown. Another measurement, carried out with common 67W and 100W chargers, records markedly lower input power, between 16 and 19W, for a full recharge in about 2h30.
The gap between these two results is probably explained by the negotiation of the fast-charging protocol, which does not engage the same way with every third-party charger. In practical terms, this power bank's recharge time is not guaranteed: it depends heavily on the charger used, which is rarely the case with the best products of this format.
The integrated cable
The USB-C cable integrated into the case avoids having to hunt for a separate one, a real benefit day to day. Its length, about 22cm, is on the other hand found short in use: it becomes difficult to hold the smartphone in hand while it charges, unlike a longer, ordinary cable.
A compact format for its power
At 249g for 10,000 mAh and up to 55W of output, the Nexode 55W remains a compact format, described as smaller than a large smartphone. This is a clearly favorable point for this product, unlike some higher-capacity models from the same brand that weigh noticeably more for comparable power.
Heat build-up under sustained charging
Several independent reports mention noticeable heat build-up in the case under sustained full-power charging, to the point that the manufacturer's own documentation recommends leaving the device in open air while it charges. An assessment carried out on a laptop records a power drop from 45W to about 22W after roughly thirty minutes of continuous charging, consistent with a thermal protection that activates to limit the rise in temperature.
Reliability, still lightly documented
The product is too recent, on sale since March 2026, for feedback covering several months or years of use to exist yet. One isolated report mentions a unit received defective and returned, without this case recurring in the other feedback reviewed. No safety incident or swelling has been reported.
The price actually observed
The official listed price is €59.99, but the price actually observed at the partner retailer commonly ranges between €35.98 and €39.98, about a third less. A gap of this size clearly changes the value for money: at full price, the product holds up less well against its recharge limits, but becomes distinctly more appealing at the price actually charged.
