Enersys CYCLON Batteries

About EnerSys CYCLON Batteries

CYCLON is EnerSys's pure lead sealed battery platform, originally developed by Gates Corporation in 1973 and now manufactured by EnerSys in Warrensburg, Missouri. What distinguishes CYCLON from conventional sealed lead-acid (SLA) batteries is the purity of the lead used in the plates — 99.99% pure, compared to the alloys used in standard SLA construction. This purity drives meaningful differences in power density, cycle life, float life, and temperature performance that make CYCLON a preferred choice in applications where conventional SLA falls short.

CYCLON batteries are UL Recognized Components and are classified as nonspillable under DOT regulations, excepting them from comprehensive packaging requirements when properly labeled.

CYCLON Single Cells vs. Monoblocs

CYCLON batteries are available in two fundamental configurations, each suited to different design and installation requirements.

Single Cells are individual 2-volt cells housed in a cylindrical steel can. The metal jacket provides exceptional shock, vibration, and temperature resistance, and the cells can be connected in series or parallel to achieve virtually any required voltage or capacity. Single Cells are the more flexible option for custom pack designs and operate across an exceptionally wide temperature range of -65°C to +80°C. They are available in D (2.5Ah), DT (4.5Ah), X (5.0Ah), E (8.0Ah), and BC (25.0Ah) capacities, plus the J cell (12.0Ah) — contact us for J cell availability.

Monoblocs are multi-cell assemblies in a plastic enclosure, providing 4V or 6V output in a single unit. Monoblocs are available in 2x3 and 1x6 configurations and are better suited for applications where a self-contained higher-voltage unit is preferred over individual cell assembly. Monobloc operating range is -40°C to +40°C. We stock Monoblocs in D (2.5Ah), X (5.0Ah), and E (8.0Ah) capacities across 4V and 6V options — contact us if you need configurations not shown above.

Key Technical Advantages of CYCLON Pure Lead Technology

Power density. Pure lead plates are thinner than alloyed lead plates, which means more surface area per unit volume and significantly higher high-rate power density. At pulse and high-rate discharge durations under 100 minutes, CYCLON batteries deliver more power per unit weight than competitive sealed lead-acid products.

Cycle life. Conventional sealed lead-acid batteries typically offer up to 200 full cycles. CYCLON Single Cells are rated for up to 300 cycles at 100% depth of discharge — 50% to 200% more cycle life depending on the competitive product being compared.

Float life. CYCLON Single Cells carry a 10-year design life at 25°C and a 15-year design life at 20°C — considerably longer than the 3 to 6 years specified for most conventional sealed lead-acid batteries in standby applications.

Fast recharge. The low internal resistance of pure lead chemistry enables CYCLON batteries to reach 95% state of charge in under one hour using conventional constant voltage charging — without loss of capacity or electrolyte. No current limiting is required with a constant voltage charger, simplifying charger design.

Temperature range. CYCLON Single Cells operate from -65°C to +80°C and deliver twice the capacity of conventional sealed lead-acid batteries at temperatures below -20°C. This makes them the practical choice for outdoor, aerospace, and extreme environment installations where conventional SLA performance degrades significantly.

Safety. CYCLON batteries emit minimal to no gas under normal charging conditions, making them suitable for deployment in occupied environments including offices, hospitals, aircraft cabins, and data centers. A resealable 50-PSI safety valve allows gases to escape and automatically reseals, eliminating both excessive gas accumulation and the "dry out" failure mode common in repeated-recharge applications.

Shelf life. CYCLON batteries have a self-discharge rate significantly lower than conventional lead-acid batteries. EnerSys recommends a boost charge every 24 months or when open circuit voltage drops to 2.00 volts per cell — whichever occurs first.

CYCLON Battery Part Numbers We Stock

We carry the following EnerSys CYCLON part numbers. All are 2V Single Cells or Monobloc assemblies as noted:

• 0810-0004 — D Single Cell, 2V, 2.5Ah
• 0860-0004 — DT Single Cell, 2V, 4.5Ah
• 0800-0004 — X Single Cell, 2V, 5.0Ah
• 0850-0004 — E Single Cell, 2V, 8.0Ah
• 0820-0004 — BC Single Cell, 2V, 25.0Ah
• 0819-0012 — D Monobloc, 6V, 2.5Ah
• 0809-0012 — X Monobloc, 6V, 5.0Ah
• 0859-0010 — E Monobloc, 4V, 8.0Ah
• 0859-0012 — E Monobloc, 6V, 8.0Ah

If you need a part number not listed above — including the J Single Cell (0840-0004, 2V, 12.0Ah), 4V Monoblocs, or standard battery assembly configurations — contact us to discuss availability.

Common Applications

CYCLON batteries are used across a wide range of standby and portable/cyclic applications. Common deployment areas include uninterruptible power supplies (UPS), telecommunications infrastructure, medical equipment, defense and aviation systems, computer backup, electric vehicles, solar power installations, and any application requiring reliable operation across extreme temperature ranges. The sealed, nonspillable, any-orientation design makes CYCLON particularly well-suited for installations where conventional lead-acid batteries present handling, safety, or orientation constraints.

Frequently Asked Questions

What is the difference between a CYCLON Single Cell and a Monobloc?

Single Cells are individual 2-volt cells in a cylindrical steel housing, intended to be connected in series or parallel to build the required voltage and capacity. Monoblocs are pre-assembled multi-cell units in a plastic enclosure, available in 4V and 6V configurations. Single Cells offer a wider operating temperature range (-65°C to +80°C vs. -40°C to +40°C for Monoblocs) and greater design flexibility. Monoblocs offer a more compact and convenient self-contained solution where higher voltage in a single unit is preferred.

Can CYCLON Single Cells be connected in series and parallel?

Yes. CYCLON Single Cells and Monoblocs can be connected in series to increase voltage and in parallel to increase capacity, or in series-parallel combinations to achieve both. EnerSys provides a range of standard assembly configurations in rigid ABS, styrene, and shrink wrap packaging — contact us if you need a configured battery pack rather than individual cells.

What charger is recommended for CYCLON batteries?

Constant voltage (CV) charging is the preferred method for CYCLON batteries. For cyclic applications, the recommended charge voltage is 2.45–2.50V per cell. For float/standby applications, 2.27–2.35V per cell is recommended. At 12V, the corresponding ranges are 14.70–15.0V (cyclic) and 13.62–14.10V (float). No current limiting is required with a constant voltage charger. Temperature compensation of approximately -3mV per cell per degree Celsius from 25°C is recommended to avoid thermal runaway at elevated temperatures. Consult EnerSys Application Support if you intend to use constant current charging.

Are CYCLON batteries approved for air transport?

CYCLON Single Cells and Monoblocs are classified as nonspillable batteries under DOT regulations and are excepted from comprehensive packaging requirements when properly labeled. They have been tested to comply with ICAO and IATA packaging requirements. Aviation installation may require FAA or other appropriate agency certification depending on the application — consult the applicable regulatory requirements for your specific use case.

How should CYCLON batteries be stored?

CYCLON batteries have a low self-discharge rate and can be stored for extended periods. EnerSys recommends a boost charge every 24 months, or sooner if the open circuit voltage drops to 2.00V per cell. If storage temperatures regularly exceed 25°C, inventory should be checked more frequently. Batteries should be stored in a cool, dry environment to maximize shelf life.

What does the 1-year warranty cover?

Our 1-year warranty covers defects in materials and workmanship under normal use. If a battery arrives damaged or fails within the warranty period, contact our customer service team at 1-800-405-2121 or online and we'll make it right. Note that EnerSys separately specifies a 10-year design float life for CYCLON Single Cells at 25°C — this refers to the battery's engineering design life, not a product warranty term.