Sentinel walk-in lithium battery storage containers.
Walk-in rooms for lithium-ion and LiFePO4 storage, staging and charging, with ventilation, detection, suppression and the AEL CORE control panel installed. Designed and built to UL 1487 and NFPA 855 standards in our Santa Rosa, California plant.
Sentinel™ Walk-In Battery Storage Enclosures: outdoor containers and indoor rooms for lithium-ion and LiFePO4 storage, staging, isolation and charging review, with available environmental controls, detection, suppression, racking, electrical integration and project documentation.
Built in-house: AEL is fully vertically integrated. Control panels, container retrofits, plumbing, electrical, fire suppression and HVAC installation, welding, sheet metal fabrication, and powder coating are all done by our own team. See our in-house capabilities.
Walk-in container sizes — Sentinel™ Battery Storage
Outdoor solutions.
8′ W × 10′ L × 9′ H · 80 sq ft
Sentinel 8×10
Compact walk-in container for smaller deployments and staging areas.
8′ W × 20′ L × 9′ H · 160 sq ft
Sentinel 8×20
Mid-size container for commercial and industrial battery storage.
8′ W × 40′ L × 9′ H · 320 sq ft
Sentinel 8×40
Full-size container for utility-scale deployments.
Built to approved specifications
Custom Sizes
Custom modular footprints are available for engineering review.
Indoor Solutions — Sentinel™ Battery Storage
Indoor solutions.
Walk-in or rack access · grey or white
Indoor Sentinel
Built inside your building, with exhaust ducted out and alarms tied into your fire-alarm system.
Need cabinet-scale storage? See Sentinel Mini™ battery cabinets.
Engineering scope
Features, systems, and available integration.
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Fire-Suppression Options
Dry chemical, clean agent, aerosol, or water-sprinkler options can be reviewed with early-warning thermal detection when required by the project.
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Side-Mounted HVAC
Climate-control options with side-mounted equipment can be sized around the battery heat load, ambient conditions, and operating criteria.
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NFPA 855 Planning Support
Sentinel enclosures are designed and built to UL 1487 and NFPA 855 standards. AEL can configure project documentation around applicable installation criteria, facility conditions, battery information, and the authority review path.
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Controls Built to UL 508A
Factory-wired control panels built to UL 508A, with BMS interfaces, gas detection, ventilation interlocks, and remote monitoring, are available as specified.
| Feature | Sentinel 8×10 | Sentinel 8×20 | Sentinel 8×40 |
|---|---|---|---|
| Exterior dimensions | 8′ W × 10′ L × 9′ H | 8′ W × 20′ L × 9′ H | 8′ W × 40′ L × 9′ H |
| Floor area | 80 sq ft | 160 sq ft | 320 sq ft |
| Construction | Rugged steel construction, fabricated and finished in-house; 1, 2 and 3-hour constructions available |
|---|---|
| Base frame | Heavy-duty steel base, ready to set and relocate |
| Doors | Standard (unless otherwise specified): one 3' × 7' single man door with lock and key, panic hardware and self-closer. Options: double doors on the long side (two 3' × 7'), 40–42 in. wide man doors, multiple sets of single or double doors, key fob entry, electric locks and fail-safe safety door locks |
| Ventilation | Gas-detection-linked emergency ventilation, engineered in-house to clear the enclosure fast and keep the site safe |
| Climate control | Engineered to hold battery temperature in your climate, with a hazardous-location rated option |
| Power | Factory-wired electrical service, sized to your site, with three-phase options |
| Controls | AEL CORE control panel, built to UL 508A, NEMA rated for indoor and outdoor installs |
| Fire suppression | Dry chemical (standard); Stat-X condensed aerosol and clean agent available |
| Flooring | Epoxy flooring (standard); custom flooring available, including anti-static flooring |
Custom sizes and indoor Sentinel configurations are available.
Included features (typical)
- AEL CORE control panel, built to UL 508A
- Visual and audible alarms
- Emergency purge at the door
- Epoxy floor
- One 3′ × 7′ single man door with lock and key, panic hardware and self-closer (standard unless otherwise specified)
- NFPA 704 hazard diamond placard
- Gas detection and ventilation interlocks with automatic emergency ventilation
Optional upgrades
- Charging battery storage add-on
- Stat-X condensed aerosol fire suppression
- 1, 2 and 3-hour constructions available
- Three-phase power or higher-amperage service
- Additional outlets, lighting and hazardous-location devices
- Enhanced controls (HMI), telematics and monitoring
- Custom flooring, including anti-static flooring
- Remote monitoring and alarm notification
- Door options: double doors on the long side (two 3′ × 7′), 40–42 in. wide man doors, multiple sets of single or double doors, key fob entry, electric locks and fail-safe safety door locks
- Fire suppression options: dry chemical, clean agent, aerosol or water sprinkler
- Deflagration venting panels
- Side-mounted HVAC system
- BMS interface connections
- Adjustable battery racking
- Stamped drawings and documentation
- Factory testing documented as specified
- Project criteria review for applicable NFPA 855 requirements
Stat-X condensed aerosol fire suppression
Sentinel supports Stat-X condensed aerosol fire suppression: a compact, pipe-free system that responds at the source of a fire, before it can spread through the enclosure.
It is made for enclosed battery spaces, where fast knockdown matters most, and it keeps installation and upkeep simpler than traditional piped systems.
AEL is an approved Stat-X distributor. Our own technicians design and install Stat-X, dry chemical and clean agent systems in-house, so suppression is coordinated with the enclosure from day one.
AEL CORE control panel
Every Sentinel ships with the AEL CORE control panel, built to UL 508A in our own panel shop and NEMA rated for indoor and outdoor installs. One familiar operator layout controls ventilation, lighting and emergency stop, and the tower light gives a one-glance status:
- Red: check airflow
- Amber and horn: purge
- No light: system OK
Lithium-ion batteries bring specific hazards: thermal runaway, toxic off-gassing and fire propagation. NFPA 855 and the fire codes that adopt it ask owners to show how an incident will be detected, contained and kept away from people and property. Sentinel answers with 1, 2 and 3-hour constructions available, integrated gas detection, emergency ventilation and Stat-X fire suppression, in a relocatable enclosure designed and built to UL 1487 and NFPA 855 standards.
Whether you are staging batteries for deployment, isolating damaged cells or holding inventory long term, Sentinel gives your AHJ a defined, documented enclosure to review.
Codes & standards
- Designed and built to UL 1487 and NFPA 855 standards
- AEL CORE control panel built to UL 508A
- Project review references: NFPA 70 (NEC), IFC / IBC and NFPA 1
Safety and scope note: AEL provides engineered enclosures and defined interfaces. Fire protection options are intended for incipient fire response and hazard isolation. This product is not designed, represented, or warranted to stop or prevent lithium battery thermal runaway. Final code compliance and Authority Having Jurisdiction (AHJ) acceptance are the responsibility of the Owner. All installations must comply with applicable local, state, and federal codes including NFPA 855, IFC, and local AHJ requirements.
Some inventories cannot sit at shipping charge for months: replacement packs that must be topped up before install, UPS modules held on a maintenance charge, fleet spares rotated back into service on a schedule. The charging add-on turns a Sentinel enclosure into a supervised charging and storage room, wired in the same shop that builds the rest of the unit.
- Dedicated charging circuits, receptacles or hard-wired charger connections, sized to the chargers you specify
- Charger mounting positions and cable routing laid out with the racking, so cords stay off the floor and out of the aisle
- Charging power can be tied into the AEL CORE control panel and cut on a gas, heat or ventilation alarm
- Exhaust and detection sized for the heat and off-gas of charging, not storage alone
- Charging scope written into the drawings and system descriptions for your AHJ review
Sentinel enclosures with the charging add-on are designed and built to UL 1487 and NFPA 855 standards. Send the charger make, model and quantity, the batteries being charged and the charging schedule, and we will size the electrical service and ventilation around them.
Download the brochure (Sentinel sizes, specifications, included features and upgrades, PDF).
Planning a battery storage building? Get a quote
Application planning
Sentinel™ Battery Storage Enclosures by application.
Product Gallery
Product and installation gallery.
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AEL CORE CP2000 control panel, built to UL 508A, NEMA rated for indoor and outdoor installs
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Facility planning
Start with the battery workflow—not a standard box.
Project requirements should be confirmed with the facility team, qualified design professionals, applicable battery guidance, and the authority having jurisdiction.
What should a facility review before selecting a lithium battery storage enclosure?
Start with the application: routine inventory, charging, service staging, recalled packs, or isolated handling. Then review battery type and condition, indoor or outdoor siting, access requirements, nearby operations, environmental controls, and the approval path for the project. AEL uses that information to scope the enclosure configuration and supporting systems.
Can a battery storage enclosure be installed indoors?
Indoor battery isolation is a site-specific design decision. The available room, building systems, battery workflow, access, ventilation approach, and local requirements all affect the solution. AEL offers modular indoor enclosure configurations and can work from the facility layout and project criteria.
How are recalled or damaged batteries handled differently from normal battery inventory?
A damaged or recalled battery may require a different isolation process than routine inventory. The battery manufacturer’s guidance, the facility safety team, and the authority having jurisdiction should establish the handling protocol. AEL can configure an enclosure around the application information provided for the project.
What fire suppression options can be integrated into Sentinel Battery Storage Enclosures?
Dry chemical suppression is standard. Stat-X condensed aerosol and clean agent systems are available, and other options can be reviewed for the project, along with detection, ventilation interlocks and control-panel integration. AEL is an approved Stat-X distributor and installs suppression with its own technicians.
What is the difference between Sentinel Battery Storage and EnergyCube BESS enclosures?
Sentinel is AEL’s battery storage and isolation enclosure line for commercial and industrial applications. EnergyCube is built for integrators who bring the batteries and power electronics while AEL fabricates the enclosure around the project configuration.
Can Sentinel be evaluated for LiFePO4 or LFP battery storage?
Yes. AEL can review lithium iron phosphate (LiFePO4 or LFP) and other lithium-ion battery formats. Chemistry is one input; battery dimensions, energy, quantity, condition, state of charge, manufacturer guidance, storage versus charging activity, and site criteria must also be confirmed.
What changes when batteries will be charged inside the enclosure?
Charging adds electrical load, heat, battery-management behavior, supervision, disconnects, ventilation, detection, and emergency-planning considerations. Charging should be identified during project scoping so the enclosure and supporting systems can be reviewed as one operating package.
How are ventilation and gas detection selected?
Ventilation and detection are application-specific. AEL reviews the battery information, expected operating condition, indoor or outdoor siting, heat load, potential off-gas concerns, alarm strategy, interlocks, discharge location, and building-control interfaces before equipment is selected.
What information supports fire-marshal or AHJ review?
The review package may include the enclosure layout, battery information supplied by the owner, equipment schedules, access and separation information, electrical and mechanical details, detection and suppression descriptions, and project drawings. Final requirements are established by the project team and authority having jurisdiction.
What sizes and racking layouts are available?
Standard Sentinel sizes are 8×10 (8′ W × 10′ L × 9′ H, 80 sq ft), 8×20 (8′ W × 20′ L × 9′ H, 160 sq ft) and 8×40 (8′ W × 40′ L × 9′ H, 320 sq ft), with custom lengths and indoor panelized solutions available. Racking, aisles, door access, service clearances, anchoring, and handling routes are configured around the selected batteries and facility workflow.
What do the tower light colors on the AEL CORE control panel mean?
Red means check airflow, amber with the horn means purge, and no light means the system is OK. The AEL CORE control panel is built to UL 508A in our own panel shop, with one familiar operator layout for ventilation, lighting and emergency stop.
Get a quote
Let’s scope
your project.
Tell us about your application and timeline. Our team — not a call center — responds within one business day.
- Built in-house: fabrication, electrical, controls and suppression by our own team.
- Approved Stat-X distributor.
- Factory testing, documented as specified.
Financing available. Explore equipment financing and leasing options
- Talk to an engineer (888) 502-6695
- Location 1402 Airport Blvd, Santa Rosa, CA 95403
- Hours Mon – Fri, 8AM – 6PM PT
Request received.
Thank you. An AEL representative will review your request and reach out to you soon.
Your inquiry:
What happens next
- Engineering review. An AEL engineer reads your request and checks it against the right product line.
- We reach out within one business day. By email or phone, to confirm scope, site conditions and timeline.
- Specs and pricing. You receive pricing and the key specifications for your configuration. Project drawings are prepared once an order is placed.