About this replacement
SumUp Air / AIR1E215 — 3.7V Li-ion Replacement Battery (DTS-1300-SW)
This is a 3.7V, 1200mAh Li-ion battery for the SumUp Air card reader (AIR1E215). It replaces OEM part DTS-1300-SW and fits directly into the Air's battery bay without any modification. When the original cell degrades and the reader dies mid-shift, this is the swap.
- SumUp Air and AIR1E215 fit: Both model variants use the same 3.7V cell, the same connector, and the same BMS handshake. One battery covers both SKUs.
- Bench tested on actual hardware: We ran this cell through full charge cycles on the SumUp Air and confirmed the BMS accepted the new cell without error flags. Charge IC entered normal CC/CV mode — no protection trip, no fault state.
- First-deployment calibration: After fitting the battery, complete one full transaction cycle before using the terminal in a live environment. The SumUp Air maps battery capacity during normal operation and needs at least one complete power cycle to register the charge indicator correctly.
SumUp Air rebooting mid-transaction after a battery swap
A fresh cell can trigger a BMS overcurrent trip if the terminal attempts a high-draw event — like a receipt print or wireless burst — before the protection circuit has settled. The BMS on a new cell starts conservatively and tightens the overcurrent threshold until it learns the load profile. This causes an unexpected reboot that looks like a firmware fault but is actually a protection event. Run two or three complete transaction cycles on the new battery and the trip threshold self-adjusts to normal operating current.
Terminal stuck at 99% charge and won't drop — new battery
This happens because the charge IC enters top-off mode on a new cell — it holds the cell at float voltage and the fuel gauge reports 99% rather than 100% until the first full discharge-recharge cycle completes. It is not a faulty battery or a faulty charger. Run the terminal down to the low-battery warning, then charge it uninterrupted to completion. After that cycle, the gauge re-anchors its 100% reference and reads correctly.