MiBoxer C4: our full review

Name: MiBoxer C4: our full review
Item: MiBoxer C4 Charger
Rating: 4
Author: Julien De Jurquet

Author: Julien De Jurquet
Review published on September 10, 2026 at 20:00 · 2 min read

Four independent bays, a complete LCD screen, and compatibility reaching LiFePO4: the C4 aims for universality, provided you select the right chemistry yourself and accept a real risk of screen failures after intensive use.

Our rating

4.0/5

How is this rating calculated?

MiBoxer C4 four-bay charger with LCD screen

The essentials

The MiBoxer C4 checks a lot of boxes for a universal charger: four independent bays, an LCD screen showing voltage, current, internal resistance, and capacity, and compatibility reaching LiFePO4, a chemistry rarely supported at this price point. The real caveat: the C4 doesn't automatically distinguish 4.35V Li-ion from 3.6V LiFePO4, you have to manually select the right mode before starting a charge, or risk overcharging a LiFePO4 cell at 4.2V. Another, rarer but documented caveat: screen failures remain possible after several weeks to several months of intensive use, offset by responsive customer support. For regular but not round-the-clock use, the C4 remains a versatile companion, with dual mains/12V power a welcome touch on road trips.

Strengths

Rare compatibility reaching LiFePO4 (3.6V), on top of Li-ion/IMR/INR/ICR and NiMH/NiCd
Complete LCD screen per bay: voltage, current, internal resistance, and capacity charged
Four independent bays with no interference, plus a discharge/test function on bay 4
Dual power input, mains (90-260V) and 12V car outlet, handy on road trips
Fire-retardant PC plastic shell with good heat dissipation

Limitations

LiFePO4 mode must be selected manually, otherwise the C4 defaults to charging at 4.2V Li-ion
Screen failures remain possible after several weeks to several months of intensive use
Only a one-year manufacturer warranty
Current capped at 1.5A per bay, slower than fast-charging USB-C models
Not to be confused with the MiBoxer C4-12, faster but without LiFePO4 compatibility

MiBoxer C4 Charger: see the full details and price →

A universal charger for several chemistries

The MiBoxer C4 is a battery charger with 4 independent bays, built for users juggling several battery formats and chemistries. It automatically detects most inserted cells and displays all the useful information on a large LCD screen.

Independent bays

1.5 A

Max current per bay

Compatible chemistries

Up to LiFePO4, with a real point of vigilance

Its compatibility is very broad: Li-ion, IMR, and ICR cells (4.20V and 4.35V depending on chemistry), LiFePO4 (3.6V), and rechargeable NiMH/NiCd batteries, from 10440 up to 26650, including the essential 18650, 21700, AA, AAA, and C.

Worth knowing: the C4 doesn't automatically distinguish 4.35V Li-ion from 3.6V LiFePO4. You must manually select the right mode with the MODE button before starting a charge, or risk charging the cell at 4.2V Li-ion by default, which isn't suited to this chemistry.

A detailed LCD screen, bay by bay

The LCD screen shows, for each bay, the voltage, charging current, internal resistance, capacity charged in mAh, and an estimated percentage. Current is manually adjustable up to 1.5A per bay, with independent charging across all 4 bays without interference. Bay 4 stands out with a discharge function that measures a cell's real capacity.

A caveat worth knowing: possible screen failures

Dual power input means the C4 works on both mains power (90-260V) and 12V via a car outlet, handy in a car or RV. The expected protections are there (reverse polarity, short circuit, automatic cutoff at end of charge), and the fire-retardant PC shell benefits from good heat dissipation.

Worth noting: a screen failure remains possible after a few weeks to a few months of intensive use, offset by responsive customer support. For regular but not round-the-clock use, this risk stays limited.

C4 or C4-12, MiBoxer or COSOOS

Be careful not to confuse this C4 with the MiBoxer C4-12, a different model, faster (up to 3A per bay) but without LiFePO4 charging. The C4 described here is the current revision (V3), the one that explicitly handles the 4 stated chemistries. This charger is distributed on Amazon through the COSOOS store, which explains why the product page sometimes lists COSOOS as the brand: the unit itself, its screen, and its packaging all carry the MiBoxer logo.

Who the C4 is for

This charger suits anyone with several battery chemistries to recharge regularly, including LiFePO4, who wants a detailed display without investing in an analyzer charger like the Xtar Dragon VP4 Plus. For heavier use or faster charging without LiFePO4, the MiBoxer C4-12 or a fast USB-C charger like the Xtar VC8 will suit better.

The rating in detail

Our rating

4.0/5

Actual charging current not measured

Battery compatibility not measured

Safety and protections 3.6

Build and endurance 3.2

Cables and connectors not measured

Actually delivered power not measured

Multi-port power sharing not measured

Protocol compatibility not measured

Size and technology not measured

Format and chemistry compatibility 4.4

Charging precision 4.2

Display and control 4.0

MiBoxer C4 Charger: see the full details and price →

The product and its alternatives

MiBoxer C4 Charger

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The MiBoxer C4 charges 4 cells at once, shows voltage, current and capacity on its LCD screen, and even handles LiFePO4: the clever universal charger.

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Xtar VC8 Charger

See price (14)

Eight cells at once: the Xtar VC8 charges, tests and grades up to eight 18650 or 21700 cells over USB-C, with a large and very detailed LCD screen.

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Nitecore UM2 Charger

$17.78 (9)

A compact two-bay charger with a large LCD screen: the Nitecore UM2 recharges over USB at up to 3A and shows voltage, current, capacity and health for each cell.

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MiBoxer C4: our full review