POS machine battery
Quick answer: POS machine batteries are lithium-ion or lithium-polymer packs, most commonly 3.7V to 7.4V at 2,000–5,000mAh for handheld terminals, with LiFePO4 or sealed lead-acid used for countertop backup. The failure mode that matters is not cycle count but continuous full-charge docking — which is why a well-specified pack lasts two to three years and a generic one often does not.
Two very different POS battery jobs
Retail terminals split into two categories, and the battery requirement is different in each. Handheld and mobile terminals run on their own battery through a shift and return to a dock to recharge — they need real energy density, a fuel gauge the terminal can read, and a pack that survives being left on charge overnight. Countertop terminals run on mains power and use the battery only to ride out a power interruption or to complete a transaction during a brief outage — they need a small, reliable standby pack rather than a large one.
| Handheld / mobile POS | Countertop POS | |
|---|---|---|
| Chemistry | Li-ion or lithium-polymer | LiFePO4 or sealed lead-acid |
| Typical voltage | 3.7V / 7.4V | 6.4V / 12.8V |
| Typical capacity | 2,000–5,000mAh | 1–7Ah |
| Duty | Full discharge over a shift, docked overnight | Float charge, occasional discharge |
| Key metric | Runtime per shift, gauge accuracy | Standby reliability, float life |
| Dominant failure | Calendar aging at high state of charge | Grid corrosion (lead-acid) or over-discharge |
Why POS packs die earlier than the datasheet suggests
A well-made 18650 cell is good for 500 to 1,000 full cycles. POS terminals rarely perform full cycles — they perform many shallow ones and then sit on a charger at 100% for the rest of the day. That combination is harder on the cell than cycling, because lithium cells age fastest at high state of charge and elevated temperature.
- High state of charge. Holding a cell at 100% accelerates the growth of the passivation layer on the anode. Calendar aging roughly doubles for every 10°C rise.
- Heat from the terminal. A handheld terminal’s processor sits millimetres from the pack, and a payment terminal is often enclosed or in direct sun at a counter.
- Shallow, frequent cycling. Less damaging per event than deep cycling, but the sheer count adds up over a three-year service life.
- Charge termination behaviour. A charger that floats at full voltage rather than terminating cleanly keeps the cell in the worst aging regime.
The practical mitigations are a BMS that terminates charge cleanly, a pack positioned away from the terminal’s heat source where the enclosure allows, and — if the platform supports it — a charge profile that holds the pack below 100% while docked.
Specifying a POS pack
| Parameter | Typical range | What to check before ordering |
|---|---|---|
| Nominal voltage | 3.7V, 7.4V, 11.1V | Must match the terminal; a mismatch can damage the input stage |
| Capacity | 1,500–5,000mAh | Size for a shift plus 25–30% aging margin |
| Continuous discharge | 1–3A | Must cover peak transmit and printer current, not just idle draw |
| Dimensions | Custom | The battery bay is fixed — lock the envelope first |
| Connector | 2–6 pin, board-to-board or wire | Pin-out and latch geometry must match exactly |
| Fuel gauge | None / SOC pin / I2C / SMBus | Required if the terminal displays battery percentage |
| Charging | CC/CV, 0.2C–0.5C | Must match the terminal’s charger profile |
| Certification | UN38.3 + IEC 62133 + CE | Match the terminal’s destination markets |
When the OEM battery is discontinued
A retail estate typically outlives the battery supply for the terminal it runs on. When the OEM stops shipping packs, the choice is usually to replace the whole estate or to find a replacement pack built to the original specification. The second option is almost always cheaper, and it is what most custom POS pack projects are.
The three things that have to match are the mechanical envelope, the connector and pin-out, and — if the terminal authenticates the pack — the fuel-gauge protocol. Voltage is the easy part; terminals that refuse to recognise a replacement usually do so because of the gauge, not the cells.
Testing and traceability
| Test | What it verifies | Frequency |
|---|---|---|
| Capacity and internal resistance | Cell consistency and pack health | Every unit |
| Peak current under transmit / print load | That the pack does not trip on real duty | Per design |
| Charge termination behaviour | That the pack is not held in an aging regime | Per design |
| Temperature rise in the terminal enclosure | Thermal margin in the real installation | Per design |
| Drop and connector retention | Survival of counter and field handling | Per design |
| Transport compliance (UN38.3) | Legality of shipment | Per design and cell change |
Certifications
- UN38.3 — mandatory transport test for any lithium cells or packs.
- IEC 62133 — baseline safety standard for portable sealed lithium batteries.
- UL 2054 / UL 1642 — North American pack and cell safety where required.
- CE / RoHS — EU conformity and hazardous-substance restriction.
Terminal specifications we build to
| Form factor | Voltage | Typical capacity | Application |
|---|---|---|---|
| Single-cell pouch or prismatic | 3.7V | 2,000–5,000mAh | Handheld terminals, PIN pads |
| Two-cell pack | 7.4V | 2,000–4,000mAh | Mobile terminals with printer |
| Three-cell pack | 11.1V | 2,000–3,000mAh | Higher-draw terminals and kiosks |
| Standby pack | 6.4V / 12.8V LiFePO4 | 1–7Ah | Countertop and kiosk power ride-through |
POS battery FAQ
What battery does a POS terminal use?
Most handheld and mobile POS terminals use a single-cell or two-cell lithium-ion or lithium-polymer pack in the 3.7V to 7.4V range, with a capacity of roughly 2,000 to 5,000mAh. Countertop terminals often use a small sealed lead-acid or LiFePO4 backup instead, because they sit on mains power.
Why do POS batteries fail early?
Three causes dominate: continuous charging at full state of charge while the terminal sits on a dock, heat from the terminal itself, and shallow but very frequent cycling. Together they age a cell far faster than the cycle count alone would suggest.
Can you make a drop-in replacement for a discontinued POS battery?
Yes — that is a common request, because terminals stay in service long after the OEM stops supplying packs. Send the original battery or a dimensioned drawing, the connector, the pin-out and the voltage, and we build to that envelope.
Does the pack need to communicate with the terminal?
If the terminal displays a battery percentage or refuses to boot on an unrecognised pack, yes. Some POS platforms authenticate the battery through a fuel-gauge IC over I2C or SMBus. Tell us the model and we match the gauge and the protocol.
What capacity should I specify?
Size from a shift, not from a day. A full retail shift is typically 8 to 12 hours; measure the terminal’s average current in that duty and add 25 to 30% margin for aging, because a pack that is exactly adequate when new will not last a shift in year two.
How long should a POS battery last?
Two to three years in continuous dock-and-discharge duty is typical for a well-designed pack, depending on the terminal’s thermal environment. Reducing the time spent at 100% state of charge is the single most effective way to extend it.
Are your POS packs certified for retail deployment?
UN38.3 for transport is standard on every pack, plus IEC 62133 for portable safety and CE / RoHS where the destination market requires them. The terminal itself will have its own certification, which the battery has to be compatible with.
Can you private-label the pack?
Yes. Label artwork, packaging and the documentation set can all carry your brand, and the BMS firmware identity can be set so the terminal sees a pack consistent with your own range.
Explore related pages
- Instrument lithium batteries
- Medical device battery packs
- Power tool replacement batteries
- Custom battery pack design
- Private label LiFePO4
- Project and custom work
Request a POS battery quote
Send the terminal make and model, the original pack or a drawing, the connector and pin-out, and your target runtime per shift — we respond with a pack concept in three working days.
