Jayco Customers


If you currently own a Jayco Caravan, chances are you are driving around with at least one BM PRO by Setec product in your recreational vehicle. Our product overview and troubleshooting section should assist you in answering any questions you may have about our ST Series and Drifter products.

Drifter Overview:

Designed specifically for caravan applications, the Drifter is a display unit that monitors water tank levels and 12 V battery charge state. Its backlit LCD presents information such as:

  • Current flowing in (charging)
  • Current flowing out (discharging)
  • Estimated battery charge status and the estimated time to discharge
  • Level indication of up to four water tanks including one waste water indicator
  • Time (digital clock) with am/pm
  • Ambient temperature ºC / ºF
  • Water pump status
  • Battery on/off status

Features also include: 

  • Back light which can be set as a night light
  • USB charger – 0.9 Amp USB charger
  • Water pump (on/off switch)
  • Battery (on/off switch) – when paired with a ST power supply, this switch will isolate the battery from the loads
  • Warning annunciator – displays if battery voltage is low

Download Drifter User Manual

ST Series Overview:

Designed for operation in RVs providing a DC power system with optional battery back-up. The ST Series product overview includes:

  • AC-DC Power Supply – Provides an isolated output for powering the load and float charging of the battery
  • Battery features -Provides full battery management including a four stage battery charger
  • Charging Control (Current and Voltage) – Limited to a maximum of 10A (ST20-III) and 15A (ST35-III) providing optimum life for the batteries
  • Battery current drain – Less than 2mA
  • Low voltage disconnect – Prevents deep discharge of the battery. Automatic reconnection occurs when battery voltage recovers
  • Auxiliary Power Input – Provides an alternative option for powering of the load and float charging of the batteries when mains voltages are not present
  • Protection features- Provides automatic protection for overload including short circuit, over-voltage, over temperature and reverse connected battery
  • Fault indication – Three indicators visible on the front fascia, including a red fault indicator
  • Remote battery isolate switch- Allows for connection to a remotely positioned switch that provides a manual disconnection of the battery from the loads and the main charger


Download ST Series User Manual

Download ST – II Series User Manual

Download ST – III Series User Manual

Jayco FAQs 

Yes, the ST35 is a smart charger and maintains batteries through float, equalise, store and trickle modes

The type of generator used will impact on how the ST35 works. Consult your dealer for approved generators

The ST Series has been custom designed according to manufacturing specifications and as such is not user settable.

Yes it is safe to leave it plugged in to 240 V continuously and yes it does act as a float charger and will not overcharge the battery

1. Check that any isolation switches installed are not turned on (for example battery switch on the Drifter)
2. Check the fuses
3. Contact us for further support


ST Series Tips and Common Questions 

Only install with the front vertical as shown – Any other orientation can cause overheating and power supply shut down
Only use the types listed in the user manual – Warning: use of other types, such as Calcium Lead, NiMH or Lithium, may not charge or may catch fire
All crimps to Quick Connect (QC) connectors must be done properly – a poor joint can overheat and cause fire. Poor joints will also be unreliable and reduce the voltage to the load

Any generator capable of generating a sinusoidal output at 240 Volts and 50 Hz. The generator manual must be read and it must be capable of delivering 560 Watts / 330 Watts at PF of 0.7 for ST35-II/ST20-II. As an example, a 2000 Watts inverter generator that we have checked was only capable of delivering 680 Watts at PF 0.4 to 0.7. This is fine to run the ST35-II/ST20-II, but it would not be able to run anything else at the same time

Generators/Inverters that supply square wave output, will generally have lower peak voltage, this may be too low to run the ST35-II/ST20-II

You can connect any DC source that is 14.8 Volts max, 20 Amps max (ST20-II) 35 A (ST-35-II). This input connects via an isolation diode directly to the fuse panel. There is no current limiting provided for this input. Any source connected to this must be current limited to less than the Battery Fuse rating or the battery fuse may blow

There should be no problem operating from both 240 Volts and AUX in as long as the AUX in does not exceed the 14.8 Volts limit defined in the manual. The AUX limit of 14.8 Volts must not be exceeded or damage to internal components will occur

It is possible that the power supply will operate in a hiccup mode if the AUX input voltage is above the voltage that the power supply is trying to regulate at, however this should not cause any problem

The product has not been designed for the connection of 2 batteries in parallel however as long as they are both the same type and state, the ST35-II/ST20-II will see multiple batteries as a single battery

It usually takes a similar time to charge the first 80% as it does to charge the last 20% of a lead acid battery

The time depends how deeply discharged the battery and charge current. A 120 Amp hrs battery connected to an ST20-II could take around 10 hours to reach 80% charge and another 10 hours to reach 100% full charge. So if it was at 60% full charge, it would take about 2.5 hours to reach 80%, then another 10 hours to reach full charge

Use the Setec BMS-001 battery monitor to keep track of your battery status.

Sealed batteries do not require any cell maintenance. Serviceable types require fluid levels to be maintained

All batteries should be regularly inspected to ensure:
• Terminals are clean
• Connections are tight and secure
• The battery is not cracked or deformed

Keeping a battery at 20 °C and not deep cycling (discharge only to 70%) can improve your battery life by up to 5 times longer than high temperatures (40 °C) and deep discharge (below 30%).
Always check battery manufacturers’ maintenance and operations for maximum battery life

Replace fuses only with the recommended fuse rating and type. – Using the wrong fuse can cause over heating of the fuse board

• To reduce impact of electrical noise
• Keep wires runs short
• Don’t allow big loops to form,
• Ensure all connections are good quality and wire size used is appropriate.
• Route wires as far away as practical from TV and Radio antennas.
• All wires from and to the power supply can be considered antennas,

Following these simple rules will reduce the size and effectiveness of the antennas