The LIR2025 is a rechargeable lithium-ion coin cell in the CR2025's 20 by 2.5 mm format, nominal 3.6 volts, around 30 mAh. A handful of self-charging car key fobs use cells in this class, but most CR2025 devices must never receive one.
LIR2025, face and side profile, drawn to scale: 20 mm across, 2.5 mm thick.
Voltage
3.6 V
Size (D×H)
20 × 2.5 mm
Chemistry
Lithium-ion (rechargeable)
Capacity
28-30 mAh (rechargeable)
Compatible replacements
CR2025: Primary 3 V cell of the same size; not electrically equivalent.
ML2020: 3 V rechargeable of similar size used in some car key fobs; check which type your fob charges.
⚠️ Match rechargeable types exactly in self-charging fobs; a primary CR cell in a charging cradle can vent or rupture.
Buying and replacement notes
If a key fob recharges when docked or inside the car, its cell is a rechargeable type; fitting a primary CR2025 there risks the fob trying to charge a non-rechargeable battery. The reverse mistake is equally bad. Identify the exact cell type printed on the old battery: LIR (3.6 V li-ion), ML or VL (3 V rechargeable lithium) and CR (3 V primary) all exist in near-identical cases.
⚠️ Keep away from children. Swallowed button batteries, especially 20 mm lithium coins, cause severe injury within hours. If a child swallows one, call the 24/7 National Battery Ingestion Hotline (US) at 800-498-8666 or poison control at 800-222-1222 immediately. What every parent should know.
Frequently asked questions
My fob battery says ML2020 but listings offer LIR2025. Same thing?
No. The ML2020 is a 3 V rechargeable lithium cell; the LIR2025 is a 3.6 V lithium-ion cell in a slightly different size. A fob designed to trickle-charge an ML cell should get an ML cell. The voltage difference matters to the charging circuit.
Can I put a CR2025 in a rechargeable fob?
If the fob charges its battery (docked fobs, some BMW and Renault designs), no: charging a primary lithium cell can make it leak, vent or rupture. If the fob never charges the cell, it was designed for a CR2025 in the first place.
How long does an LIR2025 hold a charge?
Li-ion coin cells self-discharge a few percent per month, so a charged spare is half-empty within a year. That is fine for a device that tops the cell up regularly and disqualifying for backup roles where a primary cell lasts a decade.