Charger
EPEVER Tracer 3906BP wiring diagram
Tracer3906BP: 15A MPPT, 200W at 12V / 400W at 24V, with attached leads and a 15A LOAD output. PV Voc is limited to 60V cold / 46V at 25°C. V3.5 specifies IP68; older revisions differ. Protect joints and the RS485 port.
- Compatible systems
- 12 V / 24 V
- Rated output
- 15 A
- PV open-circuit limit
- 60 V
Wiring diagram
How the Tracer 3906BP is wired.
Open this example in Crimp to use your own parts and cable lengths. Review the assumptions and installation notes as you adapt the circuit.
Cable sizing for this example
Use the diagram as a starting point for your installation. Replace the example equipment and cable lengths with your own, and check the connections against your exact model's instructions.
3 m one way
12 V system
- Wire
- 6 mm² · 10 AWG
- Example fuse
- 20 A
- Design current
- 15 A
- Voltage drop
- 2.2%
Sized against ABYC E-11. The design current is the unit's rated output. The length is one way; voltage drop includes an equal-length return.
Run-length and manufacturer assumptions
The editable example uses 3.048 m (10 ft) runs unless a shorter run is stated. Metric overviews round these to 3 m. Adapt the parts and lengths to your installation before choosing cable and protection.
Supporting parts
- 6.1 m total of 6 mm² (10 AWG) marine cable
- Terminations for 6 mm² cable, matched to the equipment's screw terminals, leads or studs
- 20 A fuse and holder on the positive run
- Heat-shrink, strain relief and terminal boots sized to the cable
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Installation notes
Before you install.
Open a question for model-specific guidance and sources.
Reviewed against manufacturer family documentation (rev. V3.5), checked 2026-10-01. Exact variant details still require confirmation. Manufacturer documentation →
Which waterproof controller is this?
The Tracer3906BP is a 15 A charge/discharge MPPT controller with attached power leads, distinct from the 100 V-input 3910BP. The V3.5 specification table, printed page 4 gives 200 W at 12 V / 400 W at 24 V rated charging power. The V3.5 electronics are rated IP68; the older V2.0 manual instead lists IP67. The catalog does not identify a generation, so confirm the installed label. The V3.5 manual still excludes salt spray, corrosive, greasy, explosive, and other severe environments; this is not blanket approval for an exposed marine installation.
How do the leads map?
PV + / PV − map to the solar lead pair and BATT + / BATT − to the battery pair. The controller also has a 15 A LOAD pair, temperature sensor, status LEDs, and waterproof RS485 connector. Those omitted leads must be identified by their physical labels before connection; do not mistake load wires for the battery supply. The 3906BP's supplied power cable is 14 AWG / 2.5 mm².
Fit the supplied waterproof cap whenever RS485 is unused. An uncapped communications port can admit water despite the enclosure rating. Protect every splice and extension to suit the location and account for voltage drop; the enclosure rating does not certify field-made joints.
What fuse and sequence are required?
The wiring instructions, printed page 2 specify a fast-acting battery fuse 1.25–2 times the rated current, within 150 mm of battery positive. For a 15 A controller this calculation spans 18.75–30 A; select an available fuse compatible with the actual conductor and installation, rather than interpreting the arithmetic as a required unusual fuse size.
Wire with the fuse removed and follow the diagram's battery, load, then PV order. Disconnect in reverse order. Check polarity carefully: the manual's reverse-polarity protection has conditions and does not protect every combination of energized battery and array.
Which array and battery settings matter?
The 3906BP's Voc ceiling is 60 V at minimum operating temperature, with 46 V at 25°C. Its MPPT range is battery voltage +2 V to 36 V. Do not copy the 100/92 V ratings from the 3910BP sibling.
Select the battery chemistry and charge/load settings through compatible RS485 software or accessories. Lead-acid operation supports 12/24 V automatic recognition; lithium voltage must be configured manually. The manual explicitly says MT50 cannot configure the lithium-related parameters.
What should be checked at startup?
The load performs an automatic test after power-up, switching on after about 10 seconds and remaining on for 10 seconds before returning to the chosen mode. Account for that if a connected device must not start unexpectedly. Confirm battery voltage, charging LEDs, load mode, and temperature settings before leaving the system operating.
Fit check
Connect it to the rest of your system.
Describe your setup to draft a system with Tracer 3906BP connected. Review the selected parts and cable lengths, then edit the diagram in Crimp.
The model only picks parts and draws the connections. Every wire size and fuse rating still comes from Crimp's own sizing, never from the model.
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Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
Tracer3906BP: 15A MPPT, 200W at 12V / 400W at 24V, with attached leads and a 15A LOAD output. PV Voc is limited to 60V cold / 46V at 25°C. V3.5 specifies IP68; older revisions differ. Protect joints and the RS485 port.
- Compatible systems
- 12 V / 24 V
- Rated output
- 15 A
- Planning charge current
- 14 A
- PV open-circuit limit
- 60 V
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
PV +
positive · input
PV −
negative · input
BATT +
positive · output
BATT −
negative · output
LOAD +
positive · output
LOAD −
negative · output
Sources and sizing method
Equipment specifications. Model details, ratings and terminal roles come from the catalog. Check your unit’s label and current manufacturer documentation for its exact revision.
Example sizing. Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. Results use the example current and run length shown above. Set your actual equipment, lengths and installation conditions in Crimp before choosing hardware.
Read how the sizing worksNext step
Plan your installation with Tracer 3906BP.
Open this example as a new project, or add this component to your existing diagram. Use your equipment and cable lengths to review the sizing.
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