MiBoxer C4 Charger

The MiBoxer C4 is a universal battery charger with 4 independent bays, built for anyone juggling several cell formats and chemistries. Made from fire retardant PC plastic, it automatically detects most inserted cells and shows all the useful data on a large LCD screen.

Its compatibility is very broad: Li-ion, IMR, INR and ICR cells (4.20V or 4.35V depending on chemistry), LiFePO4 (3.6V) and rechargeable NiMH/NiCd batteries (1.48V), from the small 10340 up to the 26650, including the common 18650, 21700, AA, AAA and C formats. One point worth flagging: the C4 cannot automatically tell Li-ion 4.35V apart from LiFePO4 3.6V, so you need to manually select the right mode with the MODE button before charging, otherwise it defaults to Li-ion 4.2V. A simple step, but one not to skip.

The LCD screen shows, for each bay, the voltage, charging current, internal resistance, charged capacity in mAh and estimated percentage. Current can be manually adjusted up to 1.5A per slot, with independent charging across all 4 bays without interference. The 4th bay stands out with a discharge function that measures a cell's real capacity, a useful way to check how much life an old battery has left.

Dual power input means the C4 runs equally well from mains (90-260V) or from a 12V car socket, handy on the road or when camping. The expected protections are present (reverse polarity, short circuit, automatic stop at full charge), and the case dissipates heat well.

Do not confuse it with the MiBoxer C4-12, a different model that charges faster (up to 3A per bay) but does not support LiFePO4. The C4 described here is the current revision (V3), the one that explicitly handles all 4 chemistries listed above. Sold under the MiBoxer brand, this charger is distributed on Amazon through the COSOOS storefront, which is why some listings show COSOOS as the brand: the unit itself, its screen and its packaging all carry the MiBoxer logo.