A charger spends its life in pockets and bags. The material it is made from decides how that goes.
Most power banks are plastic. Plastic is cheap, light, easy to mould, and perfectly adequate. We use CNC-milled aluminium alloy instead, and the reasons come down to three things a charger actually has to survive.
Heat has to go somewhere
Charging generates heat — from the cell, from the voltage conversion, and from the wireless coil. Plastic is a thermal insulator, so that heat stays near the components producing it, and warm cells age faster than cool ones.
Aluminium conducts heat roughly a thousand times better than the plastics used for enclosures. The shell behaves like a heatsink: warmth spreads across the whole body and sheds into the air instead of pooling around the cell. The bank runs cooler, holds its charging rate for longer, and the cell keeps more of its capacity over years of cycles.
Magnets need tolerance
A magnetic bank has to sit flush and centred against the back of a phone, every time. That requires the magnet array and the charging coil to be positioned accurately relative to the outside surface — and to stay there.
Machined aluminium holds tighter tolerances than moulded plastic and does not flex under load. The result is that the snap feels the same on day 400 as on day one, and the coils stay aligned rather than drifting a millimetre out over time.
It survives being carried
A power bank shares pockets with keys, coins, and zips. Plastic scuffs, then scratches, then eventually stress-cracks around the port where it is thinnest. Anodised aluminium takes the same treatment and ages more like a tool than a gadget.
| Property | Moulded plastic | CNC aluminium |
|---|---|---|
| Heat dissipation | Poor — insulates | Excellent — conducts |
| Dimensional accuracy | Moderate | High |
| Scratch resistance | Low | High when anodised |
| Weight | Lighter | Slightly heavier |
| Cost to produce | Low | Higher |
What it costs
Aluminium is heavier than plastic and considerably more expensive to machine. We think it is the right trade for a device you carry daily and keep for years, and we kept the weight in check by not chasing headline capacity: 120 g in the hand, thinner than a wallet, cool under load.
That is the whole argument. Not a premium finish for its own sake — a material chosen because it does three specific jobs better.
Common questions
Does an aluminium shell block wireless charging?
No. The area over the charging coil is engineered to let the magnetic field pass, so the metal body does not interfere with the transfer.
Is it normal for the bank to feel warm?
Yes, during active charging. The shell spreading heat is the design working. It should feel warm, never uncomfortable to hold.