Product: ST20/35

Subject: Input & Output
Q. How do I calculate the nominal input?
A. Calculate the nominal input current using the nameplate (Serial Number label) Divide the number of watts be the input voltage and add 20% eg. ST35-II = 560W/240V = 2.33 x 1.2 = 2.8A eg. ST20-II = 330W/240V = 1.38 x 1.2 = 1.7A

Subject: Battery cut-off
Q. If the battery cut-out has operated, at what external DC supply voltage does re-connection occur?
A. Battery cut-off is nominal 10.5 volts with or without mains present. *Battery reconnect is for battery (external voltage) >9V when mains present and nominal 11.65V when mains is not present.

Subject: Charging Battery from flat
Q. Can the ST series power supplies charge a battery from flat (i.e. around 9.8 to 10 Volts)?
A. The Power supply has a Low Voltage Disconnect (LVD). To help maintain good battery life, as you are probably aware, it is not good to run the batteries all the way down. The Power Supply will disconnect at 10.5 +/- 0.3V. It will then re-connect once the voltage has recovered to 11.65V +/- 0.3V. It will reconnect if mains is present and battery voltage is > 9.0V. (The 9V is pull in voltage on LVD coil). If no mains is present it will reconnect when battery voltage recovers to 11.65 +/-0.3V.

Subject: Generator
Q. Can a generator be hooked up to an ST power supply?
A. a) petrol/diesel powered generator is ok (provided sine wave output)
b) they can use the 12Vext input to also get power (from car or the +12V source) for powering and also charging of backup battery.

Subject: 240V battery and multi stage battery
Q. When you have a 240 Volt powered multi stage battery charger, do you need to disconnect the battery charge function from the Setec to prevent them fighting one another?
A. Simple answer is to turn off the SETEC ST Power supply when charging the battery from the "multi stage charger", but this means that any loads lights etc) will be operating from the battery/charger and not from the ST Power supply. Note: The ST unit may still function if both chargers are active depending on what voltage the "multi stage charger" is outputting. The best solution would be to use a ST-II series charger that provides all battery features required for extended Battey life.

Product: ST35

Subject: Battery
Q. Can Gel batteries be used in the ST 35
A. Yes they can. However it is recommended to use the Lead Acid battery

Q. Can you use a deep cycle battery on the ST 35
A. Yes you can, however the ST 35-II is a better option for the charging capabilities and will have a longer life span.

Subject: Smart Charger
Q. Is the ST35 a Smart charger ? Customer wanted to put solar on the vehicle, and will also be adding in a generator (to be used every 2nd day). He will replace the standard 100aH battery with 2 x 180aH AGM batteries. Ideally he would like to use the generator in conjunction with the ST35, but if its not a smart charger then he will bypass it and buy another PSU?
A. 1). ST35 is a simple "Float" charger, the output (battery) voltage is set to 13.65V and current limited to 10A.
Note: the ST35-II is a "3 stage smart charger"
2.) The ST35 (and ST35-II) is designed for use with "Gel" type batteries. Due to the higher "Charge" voltage required for "AGM" type batteries, we cannot guarantee that "AGM" batteries will be fully (100%) charged under all conditions (i.e. in cold environments). Under normal conditions, both battery types should achieve close to 100% capacity.
3.) The type of generator used will impact on how the ST35 works. Tests have shown that generators that provide a square wave output have a lower peak voltage and may not provide the voltage required to run the ST35.

Product: ST35/II

Subject: Humming noise when radio is on
Q. I sometime get a humming noise when listening to AM radio. What is it and can anything be done?
A. The ST35-II does cause interference (or humming) on the AM band in some installations. The interference occurs when there is no load on the ST35-II due to pulse skipping, eg the battery not connected when plugged into 240VAC mains. One suggested way to reduce the pulse skipping is to lightly load the ST35-II by turning on a light. Physically moving the radio or the ST35-II (more difficult)  can sometimes help reduce or stop the noise.

Product: ST20

Subject: Battery Charger
Q. Can the charging system be disabled?
A. There is no user adjustable way of disabling the charging system on this unit.

Subject: Altering the trickle charge
Q. Can you alter the trickle charge output voltage from 13.8V to 14.4V?
A. The trickle charge is not user adjustable, it is set at 13.8V in the factory. If your battery is very flat (say <9V), then the unit will be charging at 1.2A. However, above this it should be charging at 5amps.

Subject: Battery plugged in when not in use
Q. Is it safe to leave my ST20 plugged into 240V while not in use, and if I can, would it keep the battery fully charged?
A. Yes it is safe to leave it plugged in to 240V continuously and yes it does act as a float charger and will not overcharge the battery.

Subject: Battery not charging
Q. My ST20 unit is not charging my battery. I have run a voltameter over the unit, and he's getting 13.8V in the auxiliary input, but there is nothing coming out the battery charger.
A. 1.) Check the fuses 2.) The ST20 will not connect the Aux input voltage to the battery unless the battery voltage is above approximately 9V.
Note: If the battery is not connected, the voltage at the BAT+ terminal will read 0V.