Casio · Calculators

Casio SL-310YC battery

1 × 1.5V alkaline button cell

Casio SL-310YC uses the same Two-Way Power setup as MS-20YC: solar plus one LR54 (LR1130). Replace with (+) facing up using the bottom battery-cover latch. Do not buy LR44 for this model.

Based on: Casio documentation
Last checked: 9 October 2026
Size: 11.6 × 3.1 mm
Voltage: 1.5 V
Rechargeable: Not supported

How to replace it

How to open	Same Casio procedure as MS-20YC: press the bottom battery-cover button with a thin tip, slide the cover while holding the button, replace LR54/LR1130 with (+) facing up, reseat cover.
Orientation	(+) side facing up / visible
Access	Tool-free
Notes	Casio: replace at least every three years even if unused. Memory/tax settings can be affected when the backup cell is weak.

Important

Do not confuse with solar-only scientific models (e.g. fx-260 SOLAR II) that have no replaceable LR1130.
LR54 = LR1130 alkaline; not LR44.

Sources

Last checked 9 October 2026

Casio User’s Guide — MS-20YC / SL-310YC (Power Supply + Battery Replacement)
Product manual · casio.com

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Need a LR1130?

Casio SL-310YC uses 1 × LR1130.

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Helpful for this device

Optional tools for opening, testing or charging — separate from the battery answer.

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Fluke 101 Digital Multimeter
Accurate open-circuit voltage and basic electrical checks
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Klein Tools MM400 Multimeter
General DC voltage checks including battery terminals
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Digital multimeter
Measure open-circuit voltage and general electronics checks
Voltage alone does not establish usable capacity, especially for rechargeables.
Tester vs multimeter Buy on Amazon

Buy links are optional and separate from the battery answer.

New battery but still not working?

A fresh 1 × LR1130 should restore Casio SL-310YC if the battery was the problem. Work through the checks below before replacing the device.

Check orientation
Confirm the cell is seated correctly: (+) side facing up / visible
Check the battery type
This device needs 1 × LR1130 (alkaline). Rechargeable cells are not supported for this device. Same size does not always mean the same battery.
Check known model-specific issues
Do not confuse with solar-only scientific models (e.g. fx-260 SOLAR II) that have no replaceable LR1130. LR54 = LR1130 alkaline; not LR44.
Confirm the battery itself
For most coin cells, fitting a known-good fresh cell of the correct code is simpler than capacity testing.
Still not responding?
If a correct, fresh battery installed properly does not restore the device, the fault may be elsewhere — the device may need service or replacement.

Replacing the device?

Casio SL-310YC is still sold new. Only consider a replacement if the checks above did not help.

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Buy links are separate from the battery answer. Try the checks above before replacing the device.

Need to replace the device?

Casio SL-310YC is still sold new. Only buy another if a fresh battery and the checks above did not help.