Enersys Batteries

EnerSys Batteries: What They Are and When to Choose Them

EnerSys supplies sealed lead-acid (AGM and TPPL) and lithium-ion batteries for telecom, UPS/data centers, utilities, material handling, and transportation/marine. Choose EnerSys when you need sealed designs with standardized footprints, predictable performance, and supported charger profiles for critical backup or multi-shift fleets.

Product Families and Best-Fit Use Cases

• PowerSafe — 2 V and 12 V VRLA AGM for telecom, utility switchgear, and long-duration DC backup. Best for float/standby with infrequent discharges (about 2–8 hours). Avoid if daily deep cycling is expected.
• DataSafe — High-rate VRLA for UPS ride-through (5–30 minutes). Select by required watts-per-cell at target minutes. Avoid for frequent deep-cycle service.
• Genesis NP — Compact sealed lead-acid for security panels, emergency lighting, medical devices, and small UPS. Choose when you need sealed, spill-resistant small formats. Avoid for high-vibration starting or heavy deep-cycle duty.
• Hawker — Motive power lead-acid, including TPPL. Fit for electric forklifts and AGVs operating one to two shifts with appropriate charging and ventilation. Avoid if fast/opportunity charging is required but infrastructure is not in place.
• NexSys (TPPL) and NexSys iON (Li-ion) — Maintenance-minimized motive power solutions. Choose for fast or opportunity charging, consistent power, and reduced downtime. Avoid if lowest upfront cost is the only priority or if charger/BMS communication cannot be supported.
• Odyssey — AGM for automotive, marine, and powersports with high cranking and some deep-cycle tolerance. Good for vehicles, boats, and auxiliary loads. Not intended for large stationary strings.

Quick Selection Guide

• Reserve power: PowerSafe (long duration), DataSafe (high-rate UPS), Genesis NP (small-format backup)
• Motive power: Hawker (lead-acid/TPPL), NexSys (TPPL), NexSys iON (lithium-ion for fast/opportunity charging)
• Transportation/marine: Odyssey for cranking plus house loads

Lead-Acid vs. Lithium-Ion

Criteria	AGM/TPPL (VRLA)	Lithium-ion (with BMS)
Typical cycle life	~300–800 (AGM @ 50% DoD); ~800–1,800 (TPPL)	~2,000–4,000+ (varies by chemistry/DoD)
Maintenance	Sealed; no watering; TPPL reduces maintenance	No watering; integrated protection/telemetry via BMS
Charge time	AGM ~6–10 h; TPPL supports faster/opportunity charging	~1–2.5 h with compatible fast chargers
Upfront cost	Lower	Higher
Cold performance	Good cranking; capacity drops below 32°F	Discharge OK cold; charging often limited below ~32°F (BMS restricts)
Best use	Standby backup; predictable single-shift duty; budget-sensitive	Multi-shift fleets; rapid charge windows; space/weight constrained

Values are typical ranges. Confirm with the specific EnerSys datasheet and your duty profile.

Specifying and Sizing Basics

1. Define duty: Standby runtime (minutes/hours) or motive power shifts per day, plus peak/average load (W or A).
2. Reserve power runtime estimate: Runtime (h) ≈ [System V × Ah × usable DoD × efficiency] ÷ Load (W). Use 0.75–0.9 efficiency; high-rate discharges reduce effective capacity.
3. UPS selection: Choose by watts-per-cell at target minutes to a specified end voltage (e.g., 1.67 V/cell). Do not size by Ah for 5–30 minute rides.
4. Motive power: Traditional lead-acid supports ~1 shift per full charge (about 8 h use + 8–10 h charge). TPPL/Li-ion enable 10–30 minute opportunity charges to support 2–3 shifts without swaps.
5. Charging guidance (typical): VRLA float ~2.25–2.30 V/cell at 77°F; bulk/absorb ~2.40–2.45 V/cell; temperature compensation ~−3 mV/°C/cell. Li-ion requires the designated charger and BMS communication.

Example: A 48 V, 100 Ah VRLA string at 50% DoD and 0.85 efficiency powering a 1,000 W load: 48 × 100 × 0.5 × 0.85 ≈ 2,040 Wh ≈ ~2.0 hours (check high-rate tables for corrections).

Installation and Maintenance Essentials

• Do not mix ages, capacities, or chemistries within a string/pack.
• Use model-appropriate charger profiles (AGM/TPPL) or the specified Li-ion charger with required BMS communication.
• Maintain ambient 68–77°F (20–25°C) for VRLA; life typically halves for approximately every 18°F (10°C) rise above 77°F.
• Provide ventilation/spacing; do not block relief valves. Torque terminals to spec; label polarity; use matched cables.
• Monitor voltage, internal resistance (VRLA), and temperature in critical sites to detect early degradation.
• Storage: Keep cool and charged. Top up VRLA every 3–6 months at 68–77°F; store Li-ion at moderate state of charge per BMS guidance.
• End-of-life checkpoint: Replace when capacity drops to ~80% of nameplate or per system requirement.

When EnerSys Is a Good Fit

• Telecom, utility, and UPS applications needing standardized footprints and predictable float performance.
• Warehouses running multi-shift fleets that benefit from opportunity charging and reduced maintenance.
• Installations with limited space needing sealed batteries and minimal ventilation requirements.

When to Consider Alternatives

• Sites with extreme temperatures without HVAC/heating where battery life or charge acceptance would be compromised.
• Very deep, daily cycling where a different chemistry or larger capacity may be more economical over life.
• Facilities lacking compliant charging infrastructure or utility capacity for fast/opportunity charging.

Compatibility Notes

• UPS/telecom: Match system voltage, rack footprint, terminal orientation, and certified models. For high-rate UPS, select by watts-per-cell at target minutes.
• Motive power: Confirm pack voltage/capacity, connector (e.g., SB series), charger output/profile, and BMS communication requirements with the truck OEM.
• Transportation/marine: Verify alternator and charger compatibility with AGM profiles and temperature compensation.

Common Mistakes to Avoid

• Sizing UPS batteries by Ah instead of watts-per-cell at the required minutes.
• Mixing old and new batteries within a string, causing imbalance and early failure.
• Charging Li-ion packs with non-approved chargers or without BMS communication.
• Ignoring temperature effects on life and charge acceptance.

Safety and Compliance

• Wear appropriate PPE; follow lockout/tagout procedures and local electrical codes.
• Prevent short circuits; use insulated tools and proper covers.
• Ship and recycle per regulations. Lead-acid is widely recyclable; lithium-ion requires UN 38.3-tested transport and approved recycling channels.

Specification Checklist

• System voltage, target runtime (or shifts), and load profile (kW/kWh).
• Charge windows and available power (standard vs. fast/opportunity charging).
• Ambient temperature range, space/rack constraints, and ventilation.
• Charger model/profile and communication needs (especially for lithium-ion).
• Monitoring/service plan, replacement intervals, and recycling logistics.

FAQ

How long do EnerSys batteries last?

Standby VRLA can provide multi-year float service with limited discharges; motive power lead-acid often delivers around 1,000 cycles depending on DoD and care; lithium-ion typically achieves 2,000–4,000+ cycles. Temperature, depth of discharge, and charging practices drive actual life.

Can I replace one battery in a string?

Not recommended. Mixing new and aged units causes imbalance, uneven charging, and premature failure. Replace strings or matched sets together.

Which charger should I use?

Use a charger with the model-specific profile. Lithium-ion packs require the designated charger and BMS communication. AGM/TPPL need correct voltage/current and temperature compensation.

Is opportunity charging safe for my fleet?

Yes, if the chemistry supports it (TPPL or lithium-ion) and the charger/BMS are matched. Traditional flooded lead-acid is less suitable. Follow limits and guidance in the datasheet.

What temperatures are acceptable?

VRLA life is optimal near 68–77°F (20–25°C) and declines at higher temperatures. Lithium-ion BMS typically restricts charging below about 32°F (0°C). Always verify the specific model datasheet.