MEAN WELL DBU-3200-48 is a 48 V-class programmable battery charger with 55 A constant-current charging, a default 57.6 V boost stage and 55.2 V float stage. This model uses PMBus; select the charging curve and current for the battery and apply input and temperature derating.
Product Datasheet
Download MEAN WELL DBU-3200 Datasheet (PDF)
The DBU-3200 section is on PDF pages 15, 16, 17, 18, 19, 20, 21, 22. Refer to the complete mechanical drawings and notes when planning installation.
Model and charging application
| Full model |
DBU-3200-48 |
| Product type |
DBU-3200 1U enclosed programmable battery charger |
| Voltage designation |
48 V battery class; use the actual boost and float voltages below |
| Communication option |
PMBus standard model with no communication suffix |
| Catalogue power class |
3200 W |
Suitable battery types include lead-acid flooded, Gel and AGM, plus Li-ion lithium-iron and lithium-manganese batteries. Configure the charging curve and current for the specific battery manufacturer requirements before connection.
Applications include battery backup, charging systems and central charging infrastructure. The catalogue describes a 1U low-profile design with power density up to 37 W/in³, active PFC and active inrush limiting.
Charging output and battery selection
| Default boost charge voltage |
57.6 V |
| Default float charge voltage |
55.2 V |
| Rated charging current |
55 A |
| Voltage adjustment by SVR |
47.5 to 58.8 V |
| Recommended battery capacity |
180 to 550 Ah |
| Battery back-leakage current |
1.5 mA typical |
| Typical efficiency |
94.5% |
The default charging sequence is constant current, constant voltage, then float. The illustrated transition from constant voltage to float occurs when current falls to 10% of the constant-current level.
Use the recommended battery-capacity range and suitable current settings. A substantially smaller battery requiring a low charging-current setting can experience higher current ripple. The series power-class designation does not override voltage, current or derating limits.
Embedded charging curves and programming
| Default, programmable boost / float |
57.6 V / 55.2 V |
| Gel boost / float |
56 V / 54.4 V |
| Flooded boost / float |
56.8 V / 53.6 V |
| AGM boost / float |
58 V / 54 V |
These embedded presets use 55 A as the default constant-current setting. Select the correct battery curve; the model suffix identifies communication, not a different default battery voltage.
The PMBus version supports PMBus Rev. 1.1 at up to 100 kHz for reading information, monitoring status and adjusting output settings. Charging-curve parameters can be configured using the separately required MEAN WELL SBP-001 smart battery charging programmer and a personal computer. Refer to the installation manual for two-stage operation, stage timeouts and alternative curves.
Input, conversion and protection
| AC input range |
90–264 VAC |
| DC input range |
127–370 VDC |
| Input frequency |
47–63 Hz |
| Typical power factor |
0.97 at 230 VAC and full load |
| Typical AC current |
17 A at 230 VAC |
| Typical cold-start inrush |
55 A at 230 VAC |
| AC leakage current |
<2 mA at 230 VAC |
| Overvoltage protection |
63 to 75 V; output shutdown; reapply input power to recover |
| Overtemperature protection |
Output shutdown; automatic recovery after the temperature decreases |
Protection features also cover battery undervoltage, no battery connection and short circuit. The status indications identify the relevant operating or fault condition; follow the installation manual when diagnosing a trip.
The 60 Hz input curve permits 50% load at 90 VAC, rising to 100% at 180 VAC; 100% is shown from 180 to 264 VAC. Apply the temperature derating at the same time.
The converter block diagram identifies 110 kHz PFC and 90 kHz PWM switching.
Voltage and current programming
PV adjusts output over 75–125% of nominal voltage: 36–60 V for this voltage class. Connect the external control between CN1 pin 12 (PV) and pin 14 (−V signal).
The PV graph shows 48 V from 0 V control to just below 0.4 V, a transition to 36 V at 0.4 V, a low plateau through 1 V, and 60 V at 4.7 V through 5 V. The graph is labelled non-linear; use its plotted anchors and the installation instructions rather than assuming one linear conversion.
PC adjusts output current over 20–100% of rated current. Connect the external control between CN1 pin 11 (PC) and pin 14 (−V signal). The graph shows 20% from 0.4 to 1 V control, increasing to 100% at 4.7 V and holding through 5 V; it is labelled non-linear.
Temperature compensation and remote control
Temperature compensation is −3 mV/°C per battery cell; this voltage class uses 24 cells. Place the NTC sensor against the battery or nearby. Normal charger operation is possible without the temperature sensor.
DBU includes a 5 kΩ NTC sensor. Connect RTH+ to CN1 pin 15 and RTH− to pin 16. In a parallel installation, interconnect every unit’s RTH+ and RTH− terminals respectively even when temperature compensation is not required; attach the sensor to this common pair when used.
Remote control: connect CN1 pin 4 to +5V-AUX pin 3 for ON; leave the contact open for OFF. ON corresponds to 4.5–5.5 V and OFF to −0.5 to +0.5 V. Maximum remote-control input is 5.5 V. Auxiliary outputs remain available independently of remote ON-OFF.
Parallel operation
Use up to two DBU-3200 units in parallel. Set their output voltages within less than 0.2 V of one another, and use short, large-section output wiring.
The parallel current limit is rated current per unit × number of units × 0.9; for two of this model the resulting limit is 99.0 A. At less than 5% of the total rated output current, current sharing can become unbalanced.
Interconnect DA, DB and −V signal between units through CN500. Use twisted pairs when the control wires are long. For one unit, CN500 is not connected and SW1 is ON; for two units, connect CN500 and keep the two units’ SW1 terminations ON as shown. Interconnect RTH+ and RTH− as specified in the temperature-compensation instructions.
The built-in ORing FET supports the documented parallel arrangement. Keep both units within their input, thermal and charging limits.
DBU control and communication connections
| CN1 connector and mating parts |
HRS DF11-16DP-2DS; mating housing DF11-16DS; contact family DF11-**SC, or equivalent |
| CN1 pins 1 / 2 / 3 |
+12V-AUX / GND-AUX / +5V-AUX |
| CN1 pins 4 / 5 / 6 |
Remote ON-OFF / DC-OK / T-ALARM |
| CN1 pins 7 / 8 / 9 / 10 |
A0 / A1 / A2 PMBus address lines / D0 charging-curve selection |
| CN1 pins 11 / 12 |
PC current programming / PV voltage programming |
| CN1 pins 13 / 14 |
+V signal / −V signal; signal reference only, not load terminals |
| CN1 pins 15 / 16 |
RTH+ / RTH− temperature-sensor connections |
| CN500 connector and mating parts |
HRS DF11-8DP-2DS; mating housing DF11-8DS; contact family DF11-**SC, or equivalent |
| CN500 pins 1–2 / 3–4 / 5–6 |
DA / DB / −V signal for parallel control; signal connections must not supply the load |
| CN500 pins 7 / 8 |
SDA / SCL |
CN1 pin 1 is rated 0.8 A; its pin table gives 10.6–13.2 V. CN1 pin 3 supplies 4.5–5.5 V at 0.3 A. Both include ORing diodes and reference pin 2, GND-AUX, isolated from the main output. The auxiliary-output specification separately gives 12 V and 5 V ±10%, with maximum ripple of 450 mVp-p and 150 mVp-p respectively.
CN1 pin 5 DC-OK is high (3.5–5.5 V) when output is at or below 32 V ±1 V, and low (−0.5 to +0.5 V) when output is at or above that threshold; it is associated with battery-low protection. Pin 6 T-ALARM is high on a temperature alarm or fan failure and low when temperature and fan operation are normal. These are isolated output-only signals, referenced to GND-AUX, with a 10 mA maximum output-current rating.
PMBus address and D0 selection lines, PC and PV reference −V signal. CN500 communication is isolated and references GND-AUX. SW1 pins 1 and 2 terminate the parallel DA/DB signals. Select the complete DF11 contact reference and wire assembly for the installation; mating housings and contacts are not stated as supplied accessories.
Status indication
Green indicates float charging, stage 3. Orange indicates constant-current or constant-voltage charging, stages 1 and 2. Constant red indicates an abnormal condition such as overtemperature, overload, fan failure or charging timeout.
Flashing red indicates an internal temperature of 60°C; at this warning point the unit can continue operating normally without entering overtemperature shutdown. The catalogue specifies a warning through the PMBus interface on the PMBus version.
Cooling, derating and environment
| Operating temperature |
−30 to +70°C, subject to derating |
| Horizontal temperature curve |
100% load through 50°C, decreasing to 50% at 70°C |
| Cooling |
Built-in DC fans controlled according to internal temperature |
| Working humidity |
20–90% RH, non-condensing |
| Storage conditions |
−40 to +85°C; 10–95% RH, non-condensing |
| Temperature coefficient |
±0.03%/°C over 0–50°C |
| Vibration |
10–500 Hz, 2G; 10 minutes per cycle and 60 minutes each along X, Y and Z |
Operation between −30 and −25°C requires 230 VAC input. For operation above 2000 m, reduce the allowed ambient temperature by 5°C for each additional 1000 m. Apply input-voltage and temperature limits together and keep the fan air path clear.
Safety, EMC and reliability
| Catalogue safety approvals |
UL62368-1; CSA C22.2 No.62368-1; TUV BS EN/EN62368-1; EAC TP TC 004 |
| Withstand voltage |
Input/output 3 kVAC; input/FG 2 kVAC; output/FG 1.5 kVAC |
| Insulation resistance |
100 MΩ at 500 VDC, 25°C and 70% RH for input/output, input/FG and output/FG |
| MTBF reference |
494.2 thousand hours minimum, Telcordia SR-332; 44.8 thousand hours minimum, MIL-HDBK-217F at 25°C |
Conducted emissions: BS EN/EN55032 (CISPR32) Class B. Radiated emissions: BS EN/EN55032 (CISPR32) Class A. Harmonic current: BS EN/EN61000-3-2 Class A; voltage flicker: BS EN/EN61000-3-3.
Immunity follows BS EN/EN55035 and BS EN/EN61000-6-2: ESD 8 kV air Level 3 and 4 kV contact Level 2; radiated susceptibility Level 3; burst Level 3; surge 2 kV line-to-line and 4 kV line-to-earth; conducted susceptibility Level 3; magnetic-field immunity Level 4. Voltage dips are >95% for 0.5 periods and 30% for 25 periods; interruptions are >95% for 250 periods.
The EMC test setup mounts the charger on a 600 × 900 × 1 mm metal plate. It is a component for integration into final equipment; reconfirm the completed equipment’s EMC compliance. The catalogue lists a five-year manufacturer warranty, subject to the applicable manufacturer terms.
Dimensions, installation and ordering
| Unit dimensions |
325.8 × 107 × 41 mm (L × W × H); case 256 |
| Weight reference |
2760 g, explicit catalogue PACKING reference per unit; not a measured shipping weight |
| Carton reference |
4 units / 12 kg / 0.83 CUFT |
| Charging programmer |
MEAN WELL SBP-001; a personal computer is also required for charging-curve configuration |
| Optional finish |
Conformal coating is available by request; it is not identified by the present communication suffix |
AC terminals are 1: FG, 2: neutral and 3: line, with maximum screw torque 8 kgf·cm. The drawing marks three bottom M3 mounting holes with 4 mm maximum screw depth and 6–8 kgf·cm torque, and side M4 mounting holes with 5 mm maximum depth and 7–10 kgf·cm torque. Output bars have 6.5 mm holes; the −V and +V projections are 28 mm and 38 mm. The 12 mm maximum projection belongs to the AC-input terminals.
The drawing’s airflow arrow points toward the fan end, away from the AC and main-output connections.
All mechanical dimensions are in millimetres with a general ±0.5 mm tolerance. Unless otherwise specified, electrical parameters are measured at 230 VAC input, rated load and 25°C ambient. Follow the charger installation manual, selected communication instructions and battery manufacturer requirements.
