Midland ER102 Emergency Radio Replacement Battery 3.6V 600mAh

Midland ER102 Emergency Crank Weather Radio — 3.6V Ni-MH Replacement Battery

This 3.6V 600mAh Ni-MH battery replaces the internal rechargeable cell in the Midland ER102 Emergency Crank Weather Radio. It stores charge from both the hand crank mechanism and external power sources, keeping the radio operational when mains power is unavailable. Voltage and cell count match the original pack exactly.

• ER102 crank radio fit: The ER102 uses a low-voltage Ni-MH cell because the hand crank generator outputs a modest charge current suited to this chemistry. A Li-ion cell would require a different charge circuit — this 3.6V Ni-MH pack works within the existing onboard charge management without modification.
• Bench tested on actual hardware: We cycled this pack through crank-charge and USB-charge inputs on the ER102. The battery accepted charge from both sources and the BMS held cutoff correctly at full charge without overrun.
• First-charge protocol for crank radios: After installing, charge via the DC jack or USB port for a full 16 hours before use — do not rely on the hand crank alone for the initial charge. The crank delivers a low, variable current that cannot bring a depleted Ni-MH cell to rated capacity in a single session.

Why the ER102 shows a charging error or no charge indicator on a new battery

Ni-MH cells discharged during storage can sit below the voltage threshold the ER102's charge circuit expects to see before it begins a charge cycle. When the radio detects a voltage too low to confirm a valid battery, it may show no charge activity or a fault indicator. Connecting via the DC jack — rather than USB — delivers slightly higher input voltage, which can push the cell above the acceptance threshold and trigger the charge cycle. Leave it connected for at least 30 minutes before concluding the battery is faulty.

Talk time shorter than expected after fitting a new Ni-MH cell

A fresh Ni-MH cell does not deliver its rated 600mAh on the first discharge cycle — capacity builds over three to five full charge-discharge cycles as the crystal structure in the cells stabilises. If the radio runs noticeably short early on, this is expected behaviour, not a defective battery. Run three full cycles: charge completely via DC jack for 16 hours, then discharge by using the radio until it powers off. By cycle four, output should be close to rated capacity.