Replacement batteries for solar lights
Sources checked
A replacement battery must fit the exact light electrically and mechanically, not just share its dimensions or mAh rating. Check chemistry, voltage, size, polarity and any connector in the manual. Do not place an ordinary non-rechargeable cell in a lamp that charges it.
Diagnose short runtime before replacing the cell
Insufficient sunlight, a dirty or shaded panel, an unsuitable mode and other faults can all reduce lighting time. Check charging conditions and settings rather than assuming the battery is the only cause.
Record the exact product and original battery designation. Similar-looking cylindrical cells can have different voltages and charging requirements.
Replace according to the product instructions
Use the specified supported type, capacity range and service method. Confirm whether the battery is owner-replaceable and how seals or weather protection are restored after access.
Dispose of the old rechargeable cell through the appropriate collection route. A higher-capacity mAh number does not automatically make a cell compatible or solve a panel that cannot collect enough daily energy.