Replacement batteries for Olympus and OM1. operational modelingComputational method or mathematical model for simulating, describing or optimizing technical systems.2. optical microscopyMicroscopy technique for imaging and characterizing fine material structures. System Micro Four Thirds cameras are the subject of a teardown that focuses on why some third-party packs arrive already swollen. The batteries still appeared functional, but both units examined were slightly distended, enough to justify retiring them before they could become stuck in a camera body.
The first pair was a BLN-1 pack sold under different supplier names but with identical external construction, suggesting a common manufacturing source. Each battery uses a prismatic two-cell layout and exposes four main contacts, plus a fifth S terminal that appears to have been added to satisfy revised Japanese charger requirements. The older BLN-1 design relies on separate I and T connections for identification and temperature sensing, while charge and discharge are handled through the positive and negative terminals.
Inside the pack, the circuit is straightforward: an eight-lead dual N-channel MOSFET1. metal-oxide semiconductor field effect transistorVoltage-controlled field-effect transistor with an insulated gate, widely used in integrated circuits.2. metal-oxide-semiconductor field-effect transistorA common transistor type used here as the layout and technology reference. and a six-lead protection IC1. integrated circuitIC is the common term for an integrated circuit.2. ion chromatographyAnalytical method that separates and identifies the components of a mixture. sit on a small PCBprinted circuit boardBoard that mechanically supports components and electrically interconnects them with copper traces., with insulation strips separating the board from the cell terminals. The cells themselves carry markings that appear to indicate a September 2016 production date, which fits the age-related swelling observed in the pack. The teardown also notes that the cells are likely a common 4.2 V type with a nominal 3.7 V rating, connected in series.
A second battery, branded Newmowa, showed the same overall architecture but with different sourcing details. Its two cells were unmarked on the outside, yet the PCBprinted circuit boardBoard that mechanically supports components and electrically interconnects them with copper traces. layout again combined a dual N-channel MOSFET1. metal-oxide semiconductor field effect transistorVoltage-controlled field-effect transistor with an insulated gate, widely used in integrated circuits.2. metal-oxide-semiconductor field-effect transistorA common transistor type used here as the layout and technology reference. with a small protection device. The component markings differed from the first pack, but the function appears to be the same: basic cell protection rather than sophisticated balancing or management.
The comparison suggests that swelling in these third-party camera batteries can stem from a combination of older cells, prismatic packaging, and minimalist battery-management hardware. In this case, the packs were set aside for safety, with the teardown reinforcing how little margin there can be between a low-cost replacement battery and one that should no longer be used.