MEAN WELL NPB-450-12NFC is a programmable charger for the 12 V battery class, with a default 14.4 V boost / 13.8 V float curve, up to 25 A charging current and 420 W maximum output. Built-in NFC supports wireless configuration; CANBus provides wired control and monitoring. Select the battery-specific curve and observe input, temperature and output-voltage derating.
Product Datasheet
Download MEAN WELL NPB-450 Datasheet (PDF)
The NPB-450 section is on PDF pages 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40. Refer to the complete mechanical drawings and notes when planning installation.
Model and charging output
| Complete model |
NPB-450-12NFC |
| Series and version |
NPB-450; NFC version with built-in NFC interface. |
| Nominal battery class |
12 V |
| Default boost charge voltage |
14.4 V |
| Default float charge voltage |
13.8 V |
| Maximum charging current |
25 A |
| Maximum output power |
420 W |
| Programmable charge voltage |
10.5–21 V |
| Suggested battery capacity |
90–300 Ah |
| Typical efficiency |
92%; measured at 16.8 V charge voltage. |
| Typical leakage from battery |
<1 mA |
The voltage code identifies a battery class, not a fixed boost voltage. Maximum power is a separate limit; it is not the product of the default boost voltage and maximum charging current. Do not exceed the current, voltage or power limits together.
Lead-acid (flooded, gel and AGM) and lithium (including lithium iron and lithium manganese) batteries require their own approved charging settings. Confirm maximum charging current and the final curve with the battery manufacturer. Auto-ranging is restricted to lithium batteries with a BMS.
Input and power-factor correction
| Input range |
90–264 VAC or 127–370 VDC; observe low-input derating. |
| Input frequency |
47–63 Hz |
| Typical AC input current |
4.5 A at 115 VAC; 2.2 A at 230 VAC. |
| Typical cold-start inrush |
50 A at 230 VAC |
| Typical full-load power factor |
>0.98 at 115 VAC; >0.95 at 230 VAC. |
| Input leakage current |
<0.75 mA at 240 VAC |
Charge stages and DIP presets
Select two-stage or three-stage charging through the MEAN WELL NFC app. The two DIP switches select the four voltage presets; they do not select the number of stages.
Two-stage charging runs constant current (CC), then constant voltage (CV), and stops at the taper-current threshold. Three-stage charging runs CC, CV and then float (FV). The default transition threshold is 10% of CC; taper current can be set from 2% to 30% of CC using SBP-001 software or CANBus.
Preset switch pair 1/2: OFF/OFF = default programmable 14.4 V boost / 13.8 V float; ON/OFF = gel 14 / 13.6 V; OFF/ON = flooded 14.2 / 13.4 V; ON/ON = AGM or LiFePO4 14.6 / 14 V. Float voltage applies only in three-stage operation; confirm the preset against the battery requirements.
Programming and auto-ranging
NFC configuration can be read or written with AC power on or off, without a communication cable. NFC controls stage selection, auto-ranging and CANBus address (0–15). CANBus or SBP-001 can also program CC, CV, FV and TC. NFC does not make the charger a wireless power source.
SBP-001 is sold separately. For its connection procedure, set the two preset DIP switches to OFF, remove the remote jumper between pins 7 and 8, connect cable SBP#1 and connect the programmer to a PC by USB. The depicted cable uses HRS DF11-14DP at the charger and HRS DF11-10DP at the programmer, or equivalents, with UL1007 28AWG wire. Follow the cable diagram for assembly and restore the required remote-control connection for operation.
Auto-ranging is factory OFF. It must be used only with lithium batteries matched to a BMS; it is prohibited for non-lithium batteries. The charger waits for a suitable connected battery voltage before charging. In this mode, the panel current potentiometer adjusts 50–100% of maximum current; this adjustment is not specified as a general control for other modes.
Enable NFC on a compatible phone, open the MEAN WELL Power NFC function and hold the phone antenna within 5 cm of the charger sensing area. Read the settings, adjust the required values, select WRITE and then read them again to confirm the change. The app provides CC/CV/FV/TC, CC/CV/FV timeouts, restart-after-full voltage, two/three stages, auto-ranging, address and status. A write password is optional and unset by default. The catalogue describes Android NFC 4.1 or iOS 12 compatibility; confirm support for the actual device and app version. Temperature-compensation configuration is listed for SBP-001 software rather than the NFC app.
Derating and environmental limits
| Operating temperature and humidity |
−30 to +70°C; 20–95% RH, non-condensing. Full power is limited by the curves. |
| Horizontal temperature curve |
100% output power from −30 to +50°C, falling to 50% at +70°C. |
| Input-voltage curve |
At 60 Hz: 90 VAC = 90% load; 100–264 VAC = 100% load, subject to the other limits. |
| Output-voltage/current curve |
100% current from 10.5 to 16.8 V; the plotted current falls to 80% at 21 V. |
| Storage conditions |
−40 to +85°C; 10–95% RH, non-condensing. |
| Temperature coefficient |
±0.05%/°C over 0–50°C |
| Vibration |
10–500 Hz, 2 G; 10 min/cycle and 60 min along each X/Y/Z axis. |
Cooling uses a built-in DC fan whose speed depends on internal temperature. Keep the ventilation path clear.
Automatic thermal current reduction operates during two/three-stage charging or CANBus control: T1 is the maximum ambient temperature for 100% current; T2 is typically T1 + 5°C. The non-linear graph reaches 50% current at T2 before shutdown. This function does not replace overtemperature protection.
For this fan-cooled model, reduce the allowable ambient temperature by 5°C per 1000 m above 2000 m. Observe the installation instructions and equipment requirements; this footnote does not specify an unrestricted maximum altitude.
Protection and recovery
| Short-circuit protection |
Constant-current limiting, then shutdown after 5 seconds; re-power to recover. This mechanism is specified for a short occurring after turn-on. |
| Overvoltage protection range |
21.5–26 V; output shuts down and latches off; re-power to recover. |
| Dynamic overvoltage protection |
MCU threshold is about 125% of Vboost during CC/CV, and about 125% of Vfloat during float. |
| Battery reverse polarity |
Internal reverse detection protects against damage; remove the fault and re-power to recover. |
| Overtemperature protection |
Output shuts down and recovers automatically after internal temperature decreases. |
| Battery undervoltage |
Protection is listed; use the battery-specific charging and BMS requirements. |
Control connector and status signals
Control header: HRS DF11-14DP or equivalent. Mating housing: HRS DF11-14DS or equivalent. Contact family: HRS DF11-**SC or equivalent; select the complete contact reference for the actual wire and housing.
Pins 1 and 2 are NC; CANBus addressing is set through NFC. Pin 3 = +3.3 V, referenced to pin 4 GND(signal); pin 5 = Battery Full; pin 6 = Charger OK; pin 7 = Remote ON-OFF; pin 8 = +12Vaux; pins 9 and 10 = GND-AUX; pin 11 = CANH; pin 12 = CANL; pin 13 = NTC RTH+; pin 14 = NTC RTH−.
Battery Full and Charger OK are output-only TTL signals referenced to GND-AUX, with maximum sourcing current 10 mA. High is 4.5–5.5 V; low is −0.5 to +0.5 V. Battery Full is high when full and low while charging. Charger OK is high during normal operation and low on failure or active protection.
Remote control uses a dry contact between pin 7 and pin 8: short gives ON (10.8–13.2 V); open gives OFF (−0.5 to +0.5 V). Maximum input is 13.2 V. The charger ships with pins 7/8 shorted. Pin 8 is controlled by the remote function. GND-AUX is isolated from the main +V/−V output; keep it distinct from GND(signal). TTL, remote and CANBus signals use the isolated GND-AUX reference.
The supplied 5 kΩ NTC sensor connects to pins 13/14. Battery-temperature compensation is for lead-acid batteries in three-stage operation only, over 0–40°C. The charger operates normally if the sensor is unused.
LED: green = float or battery full; orange = charging stage 1/2; flashing orange = auto-ranging; red = abnormal OTP, OVP, short circuit, reverse polarity or charging timeout. Flashing red at 95°C internal temperature is a warning with CANBus alarm while the charger continues operation; it is not itself OTP shutdown.
CANBus functions
Built-in CANBus 2.0B controls and monitors output voltage, charging current, curve settings, internal temperature and DC output ON/OFF. Connect CANH pin 11, CANL pin 12 and GND-AUX pins 9/10. Up to 16 NFC units have addresses 0–15, set by NFC. These are remote-monitoring address limits, not an authorization to parallel power outputs.
Key command references: OPERATION 0x0000; VOUT_SET 0x0020; IOUT_SET 0x0030; FAULT_STATUS 0x0040; READ_VOUT 0x0060; READ_IOUT 0x0061; READ_TEMPERATURE_1 0x0062. READ_VIN 0x0050 is not supported by NPB-450.
Curve commands: CC 0x00B0, CV 0x00B1, FV 0x00B2, TC 0x00B3, CONFIG 0x00B4; CC/CV/FV timeout 0x00B5/0x00B6/0x00B7; CHG_STATUS 0x00B8; CHG_RST_VBAT 0x00B9; SCALING_FACTOR 0x00C0; SYSTEM_STATUS 0x00C1; SYSTEM_CONFIG 0x00C2. Manufacturer name/model/revision/location/date/serial commands occupy 0x0080–0x0088. Use the protocol manual for transaction format, scaling and permissions.
Safety, EMC and reliability
| Catalogue safety approvals |
Dekra BS EN/EN62368-1; UL62368-1. |
| Withstand voltage |
Input/output 3 kVAC; input/FG 2 kVAC; output/FG 0.5 kVAC. |
| Insulation resistance |
100 MΩ at 500 VDC, 25°C and 70% RH, for input/output, input/FG and output/FG. |
| MTBF reference |
821.0 thousand hours minimum, Telcordia SR-332; 83.4 thousand hours minimum, MIL-HDBK-217F at 25°C. |
Conducted and radiated emissions: BS EN/EN55032 (CISPR32) and BS EN/EN55014-1 Class B. Harmonic current: BS EN/EN61000-3-2 Class A. Voltage flicker: BS EN/EN61000-3-3.
Immunity: BS EN/EN61000-6-2. IEC/EN61000-4-2 ESD: 8 kV air Level 3 and 4 kV contact Level 2; -4-3 radiated: 3 V/m Level 2; -4-4 burst: 1 kV Level 2; -4-5 surge: 1 kV line-to-line Level 2 and 2 kV line-to-earth Level 3; -4-6 conducted: 3 Vrms Level 2; -4-8 magnetic field: 1 A/m Level 1. -4-11 dips: >95% for 0.5 periods and 30% for 25 periods; interruptions: >95% for 250 periods.
This charger is a component for integration; reconfirm EMC compliance in the final equipment. The catalogue lists a three-year manufacturer warranty; apply the applicable manufacturer terms.
Dimensions, mounting and accessories
| Charger dimensions |
205 × 135 × 55 mm (L × W × H); case 284A. |
| Weight reference |
1380 g, catalogue PACKING reference per unit (1.38 kg); not a measured shipping weight. |
| Carton reference |
8 units / 12.05 kg / 1.71 CUFT; not used to calculate individual weight. |
Mount using the case drawing and preserve clearance for the fan and vents. The airflow arrow points toward the AC-input/fan end. The drawing shows 5.5 mm mounting slots with 127 mm and 39 mm longitudinal location dimensions; use the complete drawing for mounting positions. Connect the marked V+ and V− DC terminals with correct polarity and observe the input earth connection.
Standard accessories: one NTC sensor wire and one remote-control mating wire. The sensor uses UL2468 24×2C; the control lead uses UL1007 28AWG and HRS DF11-14DS or equivalent. Both drawings show 50 mm wire sections and 7 mm stripped ends. Extend the battery-sensor wiring as required by the installation.
Optional order reference Carry Handle is sold separately from the charger. Its kit contains one handle, four foot pads and two screws; the installation drawing identifies two M4 screws. SBP-001 is a separately sold charging programmer; cable SBP#1 is the depicted programming connection. The charger purchase does not imply either optional item is included.
Unless a condition is stated separately, specification tests use 230 VAC input, rated load and 25°C ambient. Match the settings to the battery manufacturer requirements and follow the MEAN WELL installation manual.
