An outdoor battery project almost never needs IP68. If the enclosure sits on a wall, a pole or a pad and faces rain, splash and occasional hose-down, an enclosure rated IP67 by the manufacturer already covers it, including a 1 m flood for 30 minutes. Reach for IP68 only when the box will actually sit underwater, or in a vault or pit that floods and stays flooded. The full definition of IP68 is in what an IP68 rating means for an electronics enclosure; this article compares the two codes and drives the buying decision.
One framing rule before anything else: our enclosures are rated NEMA 4X / IP66 by the manufacturer; not UL listed. NEMA does not test, certify or endorse enclosures. In US installations, NEC 110.28 states that IP ratings are not a substitute for enclosure type ratings, so check what your specification and inspector actually call for.
The short answer
IP67 means the enclosure was tested at 1 m of submersion for 30 minutes, plus full dust tightness. IP68 means continuous submersion deeper than 1 m, or longer than 30 minutes, at depth and duration the manufacturer states on the marking. There is no fixed IP68 number: 1.5 m, 4 m and 10 m products all exist, and the rating alone does not tell you which you are buying. If your battery never goes underwater, that ambiguity is one more reason IP67 is the saner target.
Side by side
| IP67 | IP68 | |
|---|---|---|
| Dust | Dust tight, no ingress | Dust tight, no ingress |
| Water test | Immersion, 1 m, 30 min | Continuous immersion, depth and duration set by maker |
| Typical marked depth | Fixed at 1 m | 1.5 m to 10 m or more, stated per product |
| Hose or jet spray | Not the basis of the rating (that is IP65/IP66) | Not the basis of the rating |
| Cable entry burden | Glands and seals rated at least IP67 | Every gland, connector and joint must be rated IP68 at the stated depth |
| Realistic use | Rain, washdown, brief flooding, ground-mounted gear | Pits, vaults, underwater or permanently wet locations |
| Cost and lead-time impact | Standard glands, standard gasket work | Custom sealing, tested assemblies, harder to modify later |
For the spray side of the scale, see IP65 vs IP66 water jet tests: what actually differs; the fundamentals of the whole IP code system are in the IP rating chart guide.
Where IP67 wins
IP67 wins everywhere the water is temporary. Rain on a wall-mounted battery cabinet, hose splash at a ground mount, a site that puddles for an hour after a storm: all of this sits inside 1 m for 30 minutes with margin. The 48 V battery bank people build for solar sheds, gate controllers and off-grid sites is exactly this case, and outdoor solar battery enclosures: what to specify covers the heat and size questions that matter more than the second immersion digit.
IP67 also wins on practicality. Glands rated IP67 are common, cheap and standardized, and a stainless body with a gasketed door holds the rating with ordinary workmanship. Maintenance is realistic: you can open the door, replace a battery module, re-torque the glands and trust the seal again. IP67 is a fixed, published test, so two enclosures marked IP67 were tested to the same condition.
Where IP68 wins
IP68 wins when the water is permanent. A battery enclosure in a flood-prone basement pit, a sump-adjacent vault, a dock or underwater instrument feed genuinely needs it. There, the depth rating is the whole point: check the marking for the stated depth and duration, because an IP68 box rated at 2 m does not survive a 5 m installation. If submersion is the design case, also read NEMA 4X vs NEMA 6P: which rating survives submersion?, since US specifications for prolonged submersion are usually written as a NEMA 6P type, and we do not build hazardous-location or submersion-rated boxes to order.
The honest caveat: IP68 is agreed between the manufacturer and the test house. That is why arguments about whether IP68 means 1.5 m forever or something else never resolve: both answers exist on real products. Buy the marked depth, not the code.
What IP68 demands of cable entries
The enclosure body is rarely the weak point. On a battery box, the cable entries are:
- Glands. Each gland must carry an IP68 rating at the same depth as the enclosure, and the cable OD must fall inside the gland's stated seal range. One cable per gland; see two cables through one cable gland: when it works for why stacking cables kills the rating.
- Connectors. Field connectors for battery and load leads must be rated for the same immersion condition. Connector makers do publish IP67 and IP68 series, so match the numbers.
- Drains and vents. An IP68 box has none: any hole, even a 3 mm drain, is a submersion leak path. That conflicts with condensation management, so a truly sealed IP68 battery box needs an internal heater or desiccant strategy; start with when an outdoor enclosure needs an anti-condensation heater.
- Door gasket compression. Continuous submersion loads the gasket harder than a 30-minute dip. Factory-cut gaskets in a formed channel, torqued hinges and latches, not a flat sheet gasket held by screws.
For the general sealing discipline that applies to any outdoor box, sealing an outdoor junction box: glands, drip loops and drains is the practical walkthrough, and how to make an electrical enclosure waterproof with glands covers the gland installation itself.
The decision by environment
- Wall or pole mount, rain and sun only: IP66 or IP67. A standard stainless wall-mount enclosure rated NEMA 4X / IP66 by the manufacturer covers it; browse the stainless enclosure size finder.
- Ground mount, washdown, splash, occasional standing water: IP67, with glands facing down and drip loops on every cable.
- Pit, vault, flood zone, or anything underwater: IP68 with a marked depth, or a NEMA 6P type where the spec is written that way.
- Specification documents in the US: write the NEMA type, because IP codes alone do not satisfy NEC 110.28. If you are not sure which type the environment needs, the enclosure selector walks environment, size and module count into a shortlist.
What to specify
Put this on the order or quote request:
| Item | Write it as |
|---|---|
| Rating | NEMA 4X type / IP66 or IP67, manufacturer-rated (state if a listing is required) |
| Material | 316L stainless for coastal or road-salt sites, 304 otherwise |
| Size | Inside height and width for the battery, plus clearance for heat and cabling |
| Gland holes | One per cable, size and position, bottom or underside preferred |
| Gland rating | At least the enclosure rating; IP68 at stated depth if submerged |
| Extras | Gland plate if entries may change; heater or vent strategy for condensation |
If the entry set is fixed, a stainless enclosure with a gland plate keeps future changes off the enclosure wall. Custom work is delivered in 10 business days, counted from your approval of the drawing. For battery projects that also carry field I/O outdoors, the guide to selecting IP67 Modbus TCP field I/O modules for outdoor use helps keep the I/O rating matched to the enclosure.
Enclosures for this job
Catalog sizes that suit the job this article answers, picked from its subject; open one for its full specifications.
| Enclosure | Material | Outside H x W x D / display | Rating |
|---|---|---|---|
| 12 × 10 × 6 in | 304 stainless | 12 x 10 x 6 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 16 × 14 × 8 in | 304 stainless | 16 x 14 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 20 × 16 × 8 in | 304 stainless | 20 x 16 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 16 × 12 × 8 in | 304 stainless | 16 x 12 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
Questions
Is IP68 always better than IP67 for an outdoor battery?
No. IP68 only matters if the enclosure is submerged deeper than 1 m or for longer than 30 minutes. For a pole, wall or pad mount that gets rain and washdown, IP67 or even IP66 is sufficient, and simpler to seal and inspect. IP68 adds cost and makes cable entries harder, with no benefit in normal weather.
Does IP67 or IP68 cover a NEMA 4X washdown requirement?
Not automatically. An IP code and a NEMA type are different systems. In US installations, NEC 110.28 states that IP ratings are not a substitute for enclosure type ratings. If the specification calls for NEMA 4X, order an enclosure rated for that type, and check whether a listing is also required. Many enclosures carry both markings.
Can I test a DIY enclosure to IP68 myself?
Not credibly. IP68 has no fixed test condition; the depth and duration are agreed between the manufacturer and the test house, then marked on the product. You can informally check a DIY box in a tank, but the result is your own claim, not a rating. A made-to-order enclosure with manufacturer-rated IP66 or IP67 is the defensible route.
Do IP68 cable glands exist for battery cables?
Yes, several makers offer glands rated IP68 at stated depths, but only when the cable diameter matches the gland's seal range exactly, which is why one gland per cable matters. The gland must also be torqued to its specification into a correctly cut hole. The gland, not the enclosure body, is usually the limit of the whole assembly.
