About this replacement
Leica Q2 / SL2 Series — 7.2V Li-ion Replacement Battery (19 531 / BP-SCL6)
This 7.2V, 2600mAh Li-ion cell replaces the Leica 19 531 / BP-SCL6 battery. It fits the Q2, Q3, SL2, and SL2S bodies. The same battery platform powers the fixed-lens Q-series and the interchangeable-lens SL-series, so one cell covers both lines.
- Q2, Q3, SL2, and SL2S compatibility: Leica standardised the BP-SCL6 cell across both the Q and SL lines. Same voltage rail, same connector, same BMS handshake protocol. A cell that clears the Q2's authentication also clears the SL2S without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge passes on a Q2 body. The BMS accepted the cell, reported battery level correctly, and held voltage above the 6.4V low-cutoff threshold through sustained continuous shooting and 4K video recording loads.
- First-cycle initialisation on Leica bodies: Leica's BMS maps the battery-remaining display by reading the cell's discharge curve during its first full cycle. Run the first charge inside the camera body or via the Leica BC-SCL4 charger — not a generic USB-C charger — to allow accurate fuel-gauge calibration from the start.
Why the Q2 battery indicator jumps erratically after fitting a new cell
The Q2 maps its battery-remaining display against a stored discharge curve from previous charge cycles. A new cell has no history in that map, so the camera interpolates voltage readings against old data and produces inaccurate jumps — often dropping from 80% to 20% in a single burst. This is not a fault with the cell. One full charge-discharge cycle inside the camera body rewrites the curve reference and stabilises the readout. After that cycle, the percentage display tracks normally through the cell's full range.
Leica body showing "no battery" or refusing to power on with a new cell installed
Leica bodies run a BMS authentication check on every power-on. If the cell voltage sits below approximately 6.0V after storage or shipping, the camera rejects it before the authentication handshake completes. Remove the cell, place it in the BC-SCL4 charger until the charge indicator confirms it has accepted current, then reinsert it into the body. If the camera still shows no battery, hold the power button for five seconds to force a full BMS re-initialisation — the camera will power on and begin the recognition sequence again.