IP ratings get treated as a single ranking — IP67 good, IP54 less good. They are not a ranking. They are two independent measurements, and specifying a higher number than your application needs adds cost, weight and sealing complexity for no benefit.
What the two digits mean
The format is IP followed by two digits.
First digit — solid particle protection, 0 to 6:
| Digit | Protection |
|---|---|
| 2 | Objects larger than 12.5mm (fingers) |
| 4 | Objects larger than 1mm (wires, most debris) |
| 5 | Dust protected — ingress not fully prevented, but not enough to interfere |
| 6 | Dust tight — no ingress at all |
Second digit — liquid ingress protection, 0 to 9:
| Digit | Protection |
|---|---|
| 1 | Dripping water, vertical only |
| 4 | Splashing water from any direction |
| 5 | Low-pressure water jets from any direction |
| 7 | Temporary immersion up to 1m for 30 minutes |
So IP65 is dust tight and jet resistant. IP67 is dust tight and survives temporary immersion. The difference between them is entirely about water, and it only matters if immersion is a realistic scenario.
Matching the rating to the application
Across our range, the ratings map to where the pack physically lives:
IP21 — indoor wall mount. Protection against vertically dripping water and large objects. Appropriate for inverter and ESS packs mounted inside a building, where the realistic hazards are condensation and accidental contact, not weather.
IP54 — indoor enclosure and rack cabinet. Dust protected and splash resistant. The right rating for rack-mounted energy storage in a utility room or a telecom shelter — protected from the environment but not hermetically sealed.
IP65 — commercial traction, dust tight and jet resistant. The baseline for a pack mounted on a vehicle that operates in Indian road conditions: dust ingress fully prevented, and the pack survives being hosed down during washing. Our heavy-duty three-wheeler packs use IP65 steel enclosures.
IP67 — dust tight, survives temporary immersion. The rating that matters when a vehicle will be driven through standing water. For monsoon-season operation in cities where waterlogging is routine, this is not over-specification — it is the difference between a pack that survives the season and one that does not.
Where people get it wrong
Over-specifying indoor equipment. An IP67 rating on a wall-mounted indoor inverter adds sealing cost and complicates thermal management for a hazard that does not exist in that location. Sealed enclosures trap heat, and heat costs cycle life.
Under-specifying vehicle packs. An IP54 pack on a commercial three-wheeler will ingest road dust. Dust on terminals and connectors causes resistance, resistance causes heat, and heat causes failures that look like cell problems but are not.
Assuming the rating covers connectors. An enclosure rated IP67 with an unsealed connector is not an IP67 system. The rating applies to the enclosure as tested; the installed assembly is only as sealed as its weakest entry point.
Treating the rating as permanent. Gaskets age, compress and crack. A pack that left the factory at IP65 and has had its lid removed three times for service is no longer reliably IP65. Treat the rating as a design specification, not a lifetime guarantee.
A practical specification rule
Ask one question: what is the worst thing that will physically touch this pack?
- Indoor, climate-controlled, nothing touches it → IP21 or IP54
- Outdoor or vehicle-mounted, dust and washing → IP65
- Vehicle-mounted, will encounter standing water → IP67
Then verify that the connectors, cable glands and any vents carry the same rating as the enclosure. The weakest point sets the real figure.
If you are unsure which band an application falls into, describe the operating environment to the application engineering desk and we will specify against it.