The Nitecore D4 Digi-Charger is a universal smart charger compatible with almost all cylindrical
rechargeable batteries, thus eliminating the need to own several chargers. The Nitecore D4
automatically detects Li-ion, Ni-MH and Ni-Cd batteries, and through manual selection is also
capable of charging LiFePO4 batteries. Intelligent charging circuitry selects the optimal
charging mode (CC, CV and dV/dt) for a given battery and each of the D4’s four
microcomputer-controlled charging slots then monitors and charges the battery
independently. Furthermore, an integrated digital LCD screen clearly displays charging
progress, voltage, current and time while an intelligent automatic power-off function
terminates current when charging is complete.
The Nitecore D4: The world’s most advanced fully-automatic digital charger. It’s as simple as
insert, detect and charge.
Capable of charging 4 batteries simultaneously
Each of the four battery slots monitors and charges independently
Compatible with and identifies Li-ion (26650, 22650, 18650, 17670, 18490, 17500, 18350,
16340(RCR123), 14500, 10440), Ni-MH and Ni-Cd (AA, AAA, AAAA, C) rechargeable
Optimized charging design for IMR batteries
Integrated LCD panel clearly displays charging parameters and progress
Two conveniently located side buttons allow easy selection of specific battery types and
Intelligent circuitry detects the battery type and status before entering automatic charge
mode (CC, CV, dV/dt)
Automatically detects battery power status and selects the appropriate voltage and charge
mode (with the exception of LiFePO4 batteries which require manual selection)
Compatible with LiFePO4 batteries
Compatible with small capacity batteries
Automatically stops charging when complete
Features over-charge prevention to protect batteries
Features temperature monitoring to prevent overheating
Made from durable ABS (fire retardant / flame resistant)
Features reverse polarity protection
Designed for optimal heat dissipation
Certified by RoHS, CE, FCC and CEC
Input: AC 100-240V 50/60Hz 0.35A(MAX), DC 12V 1A
Output voltage: 4.2V ±1% / 3.7V ±1% / 1.48V ±1%
Output current: 375mA x 4 / 750mA x 2
Li-ion / IMR / LiFePO4: 26650, 22650, 18650, 17670, 18490, 17500, 18350, 16340(RCR123),
Ni-MH / Ni-Cd: AA, AAA, AAAA, C
Dimensions: 143mm× 99mm×36mm
Weight: 239g (without batteries and power cord)
Plug one end of the power cord or car charging adapter into the Nitecore D4 charger. Plug the other
end of the cord into an applicable outlet. The LCD display and all battery indicator bars will
illuminate as the charger runs a quick self-test. When testing is complete, the name of the
product will appear on the screen, the bars will dim and the charger will enter into stand-by
mode. If no batteries are detected within 1 minute, the charger will automatically enter Eco
Mode (the LCD backlight will turn off). When a battery is installed while in Eco Mode, simply
press any button to activate the LCD display.
The Nitecore D4 features four charging slots, each of which charges and monitors a battery
independently. Rechargeable batteries of differing chemistries and voltages may be charged
simultaneously using either 1, 2, 3 or all 4 of the charging slots. When inserting a battery,
ensure the positive and negative ends correspond with the positive (+) and negative (-)
symbols on the charger. Incorrect installation will result in failure to initiate the charging
Note: The Nitecore D4 is capable of charging 3.7v Li-ion rechargeable cells, 1.2v, Ni-MH/Ni-Cd
rechargeable batteries and 3.2v LiFePO4 batteries. See above for description of battery
When a battery is first inserted the Nitecore D4 will run a short test causing the battery indicators
bars to illuminate in sequence from the bottom to the top. When the test is complete, the D4
will enter into charging mode. If any unusual circumstances have been detected, e.g. a
backward battery installation, the battery indicator bars will blink rapidly and “Err” will be
presented on the screen to urge an immediate removal of the battery.
While in charging mode, the battery indicator bars will blink rhythmically to indicate the
on-going charging process. The battery’s power status and charging progress is indicated by
the number of bars that illuminate steadily. The LCD display will also display battery voltage,
followed by charging current and elapsed charging time in sequence. Pressing the side
“MODE” button will cycle through these charging parameters. To view the charging progress
of a different charging slot press the side “SLOT” button to select a desired slot. When
charging is complete, all five battery indicator bars will illuminate steadily and “Chg.Finish”
will appear on the LCD display.
Note: When the Nitecore D4 is charging three or four batteries, charging current will be set to 375mA.
Alternatively, when charging either one or two batteries, charging current will be set to
Charging LiFePO4 batteries
To charge LiFePO4 batteries, simply press and hold the side “MODE” button for more than 2
seconds right after the battery test completes and “LiFePO4” will appear on the LCD display
to indicate the activation of LiFePO4 charging mode. To exit LiFePO4 charging mode, simply
press and hold the side “MODE” for more than 2 seconds once again, or remove and reinstall
Charging Small Capacity Batteries
When charging batteries with a capacity lower than 750mAH (e.g. AAA, 10440 and 16340
batteries), a low charging current is recommended to help extend battery life.
To select a low charging current, while in regular charging mode, simply press the side
“SLOT” button to select a desired battery slot and then press and hold the side “MODE”
button for more than 1 second until “LOW” is displayed on the LCD display indicating
activation of low current charging mode. To exit, simply press and hold the side “MODE”
button for more than 1 second once again or remove and reinstall the battery.
Nocturnal Charging Mode
When charging a battery overnight, nocturnal charging mode is recommended. Simply press
and hold the side “SLOT” button for more than 1 second in any state until the LCD backlight
turns off thus activating nocturnal charging mode. This feature ensures a peaceful night’s
sleep without being disturbed by the D4’s LCD backlight and blinking LEDs. To exit nocturnal
mode and turn the backlight on again, press and hold the side “SLOT” button for more than 1
The Nitecore D4 is capable of activating depleted Li-ion batteries with protective circuit. After battery
installation, Nitecore D4 will test and activate the battery before charging. When a battery is detected
as damaged, the LCD displays Err, and D4 terminates its charging. Such damaged battery
cannot be activated by D4.
NOTE: Nitecore does not recommend charging 0V (depleted) unprotected Li-ion batteries
with D4 and doing so can result in battery fire or explosion.
The Nitecore D4 is equipped with an advanced ‘overtime’ safety function. The Nitecore D4 will individually
monitor the elapsed charging time for each battery slot and if a particular slot exceeds 20
hours, the D4 will automatically power off the slot and display full charging bars to indicate
completion of the charging process. This feature reduces the risk caused by batteries of
The Nitecore D4 is compatible with batteries of varying sizes, therefore when charging certain
batteries (such as 26650 and AAA), manual adjustment of the battery’s position within the slot
is recommended, as to ensure solid contact is made between both sides of the battery and
the charging slot’s metal contact points.
The Nitecore D4 is restricted to charging Li-ion, IMR, LiFePO4, Ni-MH/Ni-Cd rechargeable batteries
only. Never use the D4 with other types of batteries as this could result in battery explosion,
cracking or leaking, causing property damage and/or personal injury.
The Nitecore D4 should only be used indoors or inside a motor vehicle and under no circumstances
should it be exposed to water, high humidity and low or high ambient temperatures.
Do not disassemble or modify the charger.
Children under the age of 18 should be supervised by an adult when using the D4.
The Nitecore D4 ’s safe operating temperature is between 0-40ºC。
Do not use or store the charger near open flames, direct sunlight, heating devices or other