Attwood 90821 Standard Vented Battery Box – Group 16, Black
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
The Attwood 90821 is a vented marine battery box sized for Group 16 batteries, including smaller flooded lead-acid batteries used in personal watercraft, smaller outboard-powered boats, and similar applications. Built from acid-resistant polypropylene and compliant with ABYC standard E-10 and USCG Specification 183.420, it meets the same standards as larger Attwood battery boxes in a compact footprint.
Four enlarged cable openings (0.55" diameter) allow clean routing of battery cables without tight bends, and large handles with rolled edges make the box easy to carry and position during installation. Mounting hardware is included.
- Fits Group 16 batteries
- Vented design — allows hydrogen gas to escape safely during charging of flooded lead-acid batteries
- Four enlarged cable openings — 0.55" diameter for clean, unrestricted cable routing
- Large handles with rolled edges for comfortable carrying
- ABYC E-10 and USCG 183.420 compliant
- Acid-resistant polypropylene construction
- Mounting hardware included
- Black finish
Best Use Case: Designed for Group 16 flooded lead-acid batteries in personal watercraft, small tenders, or compact outboard-powered boats where a smaller battery enclosure is needed. Also suitable for auxiliary or accessory batteries in larger vessels where space is limited.
Parts Desk Insights: This is a vented box — correct for flooded lead-acid (wet cell) batteries that off-gas hydrogen during charging. If you are installing a sealed AGM or gel battery, a non-vented box is more appropriate. For larger battery groups, see the Attwood 90651 Standard Vented Battery Box – Group 24/24M, the Attwood 90671 Power Guard Vented Battery Box – Group 27M, or the Attwood 90707 PowerGuard Pro Battery Box – Group 24/27. For a snap-top style enclosure, see the NOCO BG31 Snap Top Battery Box for Group 24–31.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.