About this replacement
Sony DSLR-A100 / A200 / A300 / A350 — 7.4V Li-ion Replacement Battery (NP-FM500H)
This is a 7.4V, 2000mAh Li-ion replacement for the Sony NP-FM500H battery pack. It fits the DSLR-A100, A200, A300, and A350 bodies, along with over 110 additional Sony Alpha DSLR models sharing the same battery bay and connector. The cell is rated at 14.8Wh and slots directly into the camera's grip compartment.
- Alpha DSLR platform compatibility: The A100 through A350 series all run on the same 7.4V battery rail with a shared connector pinout and BMS handshake protocol. Sony kept this battery form factor consistent across several generations, so one cell covers a wide range of Alpha bodies without modification.
- Bench tested on actual hardware: We cycled this cell through the DSLR-A300 body and a Sony BC-VM10 charger. The BMS accepted the cell on the first charge cycle, reported capacity correctly, and held voltage above 7.0V through sustained burst shooting and live-view use.
- First-cycle initialisation on Alpha bodies: Run one full charge cycle through the camera body or OEM charger before a heavy shoot. Sony's Alpha BMS maps the discharge curve during that first cycle — skipping it can cause the battery indicator to read inaccurately for the first few sessions.
Why the DSLR-A100 battery percentage jumps erratically after a swap
The A100 uses a voltage-threshold system to estimate remaining charge. A new cell has a slightly different discharge curve than an aged OEM pack, so the camera maps those voltage thresholds incorrectly on the first few cycles. You may see the indicator drop from 75% to 20% in a single burst sequence. After two or three full charge-discharge cycles through the camera body, the readings stabilise and track accurately through the rest of the cell's life.
Flash recycling slowing mid-shoot on a new NP-FM500H replacement
The built-in flash on A-series bodies draws a sharp current spike to recharge the capacitor between shots. If recycling time noticeably lengthens mid-shoot, the cell voltage is sagging under that capacitor-recharge load — usually below 7.0V. On the bench, we saw this begin when the replacement cell had not completed its first full conditioning cycle. Charge to 100% via the BC-VM10 or in-body charger, then discharge fully through shooting before your next session. Cell voltage should hold above 7.0V through a full card of flash-assisted frames once the cell is properly conditioned.