| Lithium-ion (Li-ion) | 3.6–3.7 V per cell | 1,500–5,000 mAh per cell or battery pack | Approximately 150–250 Wh/kg | Typically about 300–800 full cycles, depending on cell chemistry, depth of discharge, temperature, and charging profile | High energy density, compact size, low self-discharge, and good support for portable terminals | Requires protection circuitry; vulnerable to overcharge, over-discharge, heat, and physical damage | Handheld POS terminals, mobile payment devices, barcode scanners, and portable receipt printers |
| Lithium-polymer (Li-Po) | 3.7 V nominal; 4.2 V when fully charged for many single-cell designs | 800–6,000 mAh, depending on enclosure size and product design | Approximately 130–220 Wh/kg | Typically about 300–600 full cycles when properly charged and stored | Flexible pouch shapes, thin profiles, and efficient use of limited internal space | Pouch cells need mechanical protection; swelling, puncture, high temperature, or incorrect charging can create safety risks | Thin handheld POS devices, smart payment terminals, and custom-shaped battery compartments |
| Lithium iron phosphate (LiFePO4) | 3.2 V per cell | 1,000–10,000 mAh, usually in larger or specialized packs | Approximately 90–160 Wh/kg | Often about 2,000–5,000 cycles, with strong thermal and chemical stability | Long service life, improved thermal stability, and lower risk of thermal runaway than many cobalt-based lithium chemistries | Lower energy density and a different voltage curve; may not be electrically compatible with a Li-ion POS device | High-duty-cycle equipment, payment kiosks, and applications where long service life is more important than minimum size |
| Nickel-metal hydride (Ni-MH) | 1.2 V per cell | 800–3,000 mAh per cell or pack | Approximately 60–120 Wh/kg | Typically about 300–500 cycles; performance depends on charge control and operating temperature | Lower material toxicity than nickel-cadmium and relatively robust in moderate operating conditions | Heavier and larger for the same energy; higher self-discharge and usually less suitable for thin modern POS terminals | Legacy POS equipment, specific battery bays, and devices designed for multi-cell Ni-MH packs |
| Sealed lead-acid (SLA) | 6 V or 12 V per battery | 1,200–9,000 mAh or higher | Approximately 30–50 Wh/kg | Often about 200–500 cycles, depending on discharge depth and maintenance | Low cost, widely available, and suitable for backup power systems | Very heavy and bulky; unsuitable for most handheld POS products and sensitive to deep discharge | Stationary POS backup systems, kiosk power supplies, and uninterruptible power applications |
| Rechargeable lithium battery pack with BMS | Commonly 3.7 V, 7.4 V, or 11.1 V nominal, depending on cell count | 2,000–10,000 mAh, depending on voltage and enclosure volume | Depends on the selected cell chemistry | Depends on cell quality, BMS settings, charging current, and operating temperature | Can integrate overcharge, over-discharge, overcurrent, short-circuit, and temperature protection | Battery-management settings, connector wiring, communication protocol, and charger parameters must match the POS device | Most modern portable POS terminals requiring a custom replacement or original-equipment-compatible pack |
| Selection note: The battery chemistry alone does not determine compatibility. Confirm the device's original voltage, capacity, dimensions, connector, polarity, protection circuit, charging method, operating temperature range, and communication requirements before placing a supplier order. |