Sharp AD-MS10BT Replacement Battery 3.7V 2400mAh Li-ion

Sharp MD-CS100 / MD-MS200 Series — 3.7V Li-ion Replacement Battery (AD-MS10BT)

This is a 3.7V, 2400mAh lithium-ion battery built to the AD-MS10BT specification. It fits the Sharp MD-CS100, MD-MS100, MD-MS200, and MD-SS70 portable MiniDisc recorders and players. Voltage and cell dimensions match the original pack exactly: 71.00 × 19.70 × 19.70mm.

• MD-CS100 / MD-MS100 / MD-MS200 / MD-SS70 fit: All four models share the same battery bay dimensions, voltage rail, and connector pinout. A single cell at 3.7V powers both the laser mechanism and the digital signal processor across the range, which is why one pack covers the full lineup.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on MiniDisc hardware. The BMS accepted the cell without error flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• MiniDisc recording draw tip: Active recording engages both the laser write head and the compression encoder simultaneously — a noticeably higher draw than playback-only mode. Avoid switching between record and playback repeatedly in quick succession; each mode transition spins the disc mechanism up from rest and adds short current spikes that age the cell faster than sustained use in either mode alone.

Why the MD-CS100 shows a dead battery indicator on a freshly installed replacement cell

The MD-CS100 maps its battery indicator to a voltage-threshold table calibrated during the original cell's first charge cycle. A new cell arrives at a storage charge — typically around 3.6V — which sits near the bottom of that table. The device reads this as low or depleted, even though the cell has full capacity available. Running one complete charge cycle through the device before use resets the threshold mapping and brings the indicator in line with actual charge state.

Battery percentage dropping suddenly during active MiniDisc recording

Recording mode draws current from two subsystems at once — the laser assembly and the ATRAC encoder. When both fire simultaneously on a cell that hasn't yet been conditioned, the combined load causes a sharper voltage sag than the indicator algorithm expects. The display interprets that sag as a steep capacity drop and jumps the percentage down. This levels out after one or two full charge-discharge cycles; the indicator stabilises once the BMS has a discharge curve to reference. If it persists past three cycles, check that the cell contacts are clean and making firm contact — a partial connection amplifies voltage sag at high draw.