Three power inputs — wall, car, power bank — means the cooling module is sized for the weakest one. Ten thousand milliamp-hours over four hours is under ten watts. Plugging it into the wall doesn't make it colder. It makes it the same.
Half the hall had a version of it: a soft bag with a handle, a zip, a quilted shell, and a all number glowing on the front.
The number is why people pick it up.
It's a cooler. Thermoelectric, no battery inside. Plug in a power bank and it holds cold for about four hours. Plug it into a wall socket, or a cigarette lighter, and it runs for as long as you leave it on.
Three ways to power one bag — which sounds like three times the product.
It isn't. It's one product, sized for the weakest of the three.
The arithmetic
A 10,000 mAh power bank holds roughly 37 watt-hours. Four hours of run time means the bag is drawing something like eight to nine watts.
Call it ten.
A thermoelectric module running on ten watts moves very little heat — a few watts of cooling at best, because the technology's efficiency is low by nature. That's not a defect. It's the physics of the component.
Which means this is not a fridge. It's a box that holds a temperature difference of some degrees below the air around it.
That's genuinely useful. It's just not what "refrigerated" means.
"Four hours" is a condition, not a spec
Four hours from what starting temperature, to what target, with what inside the bag, in a room at what temperature?
Nobody prints that on the box, and almost nobody asks. The number is real — it was measured under some set of conditions the factory chose. Whether those conditions resemble your customer's beach is a different question.
Four hours is not a measurement. It's a set of assumptions somebody made on your behalf.
And it's the same trick as a 4K label on a kids camera — a number that describes the software, not the sensor.
The wall socket doesn't help
This is the part worth understanding, because it explains everything else.
A cooling module that can run off a power bank is a module that was sized for a power bank — ten watts, more or less. Plug it into mains and you're feeding a ten-watt machine more current than it can use. It does not get colder. It runs the same.
And it can't be fixed with a bigger adapter. If the module were built to pull forty watts from a wall, it couldn't run off a power bank at all.
Three inputs means the design takes the intersection, not the union. The bag is as strong as its weakest power source, and the weakest source is the one in your customer's pocket.
Three cables, three problems
The bag ships with a wall adapter, a car lead, and a U input for a power bank. Three ways to power it, three ways to get it wrong.
The wall adapter. Check the certificate, the model number, and the plug. The plug is the one that ruins orders — it's market-specific, and factories default to US or Chinese. Ship EU stock with a US plug and you have a container of products nobody can plug in.
The car lead. Length matters more than people expect, and so does what happens when the engine starts and the voltage dips.
The power bank. Which one? How much current does the bag need before it will start? A bag that won't boot on a power bank your customer already owns is a return, not a sale.
The module isn't yours
One vendor had a brochure on the table: `Fridge & Aroma Diffuser Integrated Solution`.
The card beside it said automotive electronics.
Put those two together and the category explains itself: the cooling didn't come from the bag industry. It came from people who build car fridges, looking for a new market for the same module.
Which has a consequence most buyers miss. If the module is sold as a solution, everyone at that show can buy the same cooling. "It refrigerates" is not a differentiator. It's a component — and the bag around it is the cheap part.
What to ask before you order
- "Four hours at what ambient temperature, with what inside, cooling to what?" If the answer is vague, the number is marketing.
- "What's the minimum input current?" This decides which power banks your customers can use — and whether you get "doesn't work" reviews.
- "Which market version is the wall plug?" Put the country or the plug standard in the PO. Not "for Europe".
- "Does the packaging say 'power bank not included' in the buyer's language?" That's not a translation task. It's your return rate.
- "Who makes the cooling module?" Not the bag. The module. It tells you what you're actually reselling.
Straight answers
Is a thermoelectric cooler a fridge?
No. It's a heat pump on a tight budget. It holds a temperature differential; it doesn't pull a box down to four degrees. Calling it a fridge is where the returns begin.
Why is there no battery inside?
Because a battery would multiply the freight cost, add a transport declaration, and put a lithium cell in a bag that gets left in a hot car. Leaving it out is the right engineering call — and it's also why the product can't work on its own.
Can I sell it as "refrigerated"?
You can. Then you'll spend six months explaining the difference between "cold" and "cooler than the room". who actually pays for a wrong first batch
What about the aroma version?
Same arithmetic, one more module. And now the manual has two things to explain instead of one.
The honest part
Nothing about this product is a lie. It cools. It runs off a power bank. It works in a car. All three are true.
What's missing is the word "slowly", the number "ten watts", and the phrase "power bank not included".
None of those are lies either. They're just the parts that don't fit on the box.
The gap between what's printed on the packaging and what's buried in the manual is the entire customer experience of a cheap product. And it's the one thing you can fix without changing the product at all.
— Damon, Founder
