Sourcing LED Flood Lights from China: Lumens, Drivers and Water Ingress

Few lighting categories are as commoditized as the LED flood light. Every factory offers a wall of wattages at prices that look almost too low. That is because the cost is hidden in three places the buyer rarely inspects: the driver, the heat sink, and how honestly the thing is sealed against water. Get those wrong and you will be processing returns by the pallet within a year.

Lumens, efficacy and why "watts" is a distraction

Traditional buyers think in watts because that is what they replaced. But the customer is buying light output, so the number that matters is lumens — specifically, delivered lumens at the fixture, not the raw LED token.

Efficacy (lm/W): a modern flood light should land around 100–140 lm/W at the fixture. A 100W flood light at 130 lm/W gives roughly 13,000 lumens. If a factory claims far more than that from the same wattage, they are quoting bare-LED lumens and ignoring optics and thermal losses.
Beam angle: floods are not all floods. 120° is a general wash; tighter angles (60°, 90°) concentrate output. Confirm the angle because it changes the perceived brightness dramatically.
CCT and CRI: 3000K–6500K options matter for different markets. For commercial and facade use, CRI of 70+ is fine; for anything where color rendering matters, ask for 80+.

The driver: the part that actually dies

In the field, the LEDs almost always outlive the driver. That is why the driver spec matters more than the chip brand. What to ask:

Isolated, constant-current driver. Isolation is a safety requirement and a longevity marker.
Power factor: for anything above a few tens of watts, a PF of 0.9 or higher is expected. Poor PF causes flicker issues and fails commercial specs.
Flicker: some cheap drivers flicker at a level that is invisible in a warehouse but painful on camera and to sensitive eyes. Ask about flicker percentage.
Surge protection: outdoor lights face lightning-induced surges. A driver with a stated surge rating (e.g., 2kV or more) will save you warranty claims.
Capacitor brands: reputable electrolytic capacitors (the well-known Japanese brands) are a genuine quality marker and worth asking about by name.

Thermals: the heat sink is not cosmetic

LEDs degrade faster when hot. A properly designed flood light moves heat away from the emitter and spreads it across a finned aluminium body. Signs of a cheap build:

Thin, small heat sink relative to wattage, so the body runs scalding at the diode.
Plastic housing with a metal plate glued in. Look for die-cast aluminium.
No thermal interface material (TIM) between the LED board and the heat sink, or a cheap pad instead of proper paste and screws.

Ask the factory for the thermal resistance and a maximum ambient temperature rating. A light rated for 45°C ambient that is sold into a hot climate will fail early regardless of everything else.

IP rating and construction

Outdoor flood lights are usually sold as IP65 or IP66. That rating is a claim about sealing, and it is routinely over-stated in this category. What to verify:

Gasket design: a real silicone gasket with a defined compression, not a thin bead of glue.
Cable entry: a proper gland or sealed entry point. This is the most common water entry path.
Breathable vent: a good design uses a hydrophobic vent to equalise pressure without letting water in. Without one, temperature cycling can suck moisture into the housing.
IP test report: ask whether the factory can supply an IP test report from a third-party lab, not just a self-declaration.

Certifications for the target market

Lighting is heavily regulated, and the certification burden sits with the importer as much as the factory:

CE / UKCA with the relevant directives (LVD, EMC, RoHS, and ERP for energy performance) for Europe.
UL / ETL for the US, and FCC for any RF or non-luminous electromagnetic compliance.
DLC listing if you are selling into utility-rebate markets in North America.

Confirm who owns the test reports and whether the certificate name matches the factory — a mismatch is a red flag for a trading company passing off someone else's reports.

MOQ, customisation and packaging

Flood lights are one of the easier categories to private-label: the housing is standard, and the branding usually goes on the label and the box. Typical MOQs for a custom carton run are modest, often in the low hundreds per SKU. Two things worth negotiating: a defined CCT and beam-angle range you hold in stock, and a written lumen-maintenance spec (for example, L70 at 25,000 hours) so your marketing claims are defensible.

Get a sample, run it continuously for a few days, and put it through a hose test if it is going outdoors. The two failures you will actually see — driver death and water ingress — are both testable before you commit.