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Same size, different electrical family

LR41 / AG3 vs SR41 / 392

The 7.9 × 3.6 mm envelope matches, but the electrical families do not: Alkaline manganese dioxide / zinc at 1.5 V nominal versus Silver oxide / zinc at 1.55 V nominal. Physical fit is not equivalence.

Same size, different electrical family

The 7.9 × 3.6 mm envelope matches, but the electrical families do not: Alkaline manganese dioxide / zinc at 1.5 V nominal versus Silver oxide / zinc at 1.55 V nominal. Physical fit is not equivalence.

Top profile · Ø 7.9 mm
Side profile · 3.6 mm high
Original proportional profiles. Scale is consistent within this diagram; screen size is not a physical ruler.
Top profile · Ø 7.9 mm
Side profile · 3.6 mm high
Original proportional profiles. Scale is consistent within this diagram; screen size is not a physical ruler.
FieldLR41 / AG3SR41W / 392
Dimensions7.9 × 3.6 mm7.9 × 3.6 mm
Voltage1.5 V nominal1.55 V nominal
ChemistryAlkaline manganese dioxide / zincSilver oxide / zinc
DrainGeneral-purpose alkaline; sloping discharge profileW: higher-drain profile
RechargeableNo — primary cell; do not recharge.No — primary cell; do not recharge.

Direct answer

LR41/AG3 and SR41W/392 share 7.9 × 3.6 mm dimensions. The first is 1.5 V alkaline; the second is 1.55 V silver oxide with a W higher-drain designation.

Both are 7.9 mm in diameter; heights are 3.6 mm and 3.6 mm. The 7.9 × 3.6 mm envelope matches, but the electrical families do not: Alkaline manganese dioxide / zinc at 1.5 V nominal versus Silver oxide / zinc at 1.55 V nominal. Physical fit is not equivalence.

Do not infer acceptability from fit alone. The device maker’s complete code and current instructions remain authoritative.

Why these codes are confused

LR41 / AG3 and SR41W / 392 share part of their dimensions, naming pattern or retail context. The table separates the four fields that a one-line cross-reference can hide.

When the alternative may be acceptable

Only when the device or battery manufacturer explicitly permits the alternative after accounting for size, nominal voltage, chemistry and drain behaviour. Otherwise use the specified family. Never stack cells or modify a compartment to compensate for a height difference.