Frequently Asked Questions

Questions about Power Supplies

Questions about Inverters

Questions about batteries

Power Supplies for LED lighting

Invertech provides you with a HLG range for LED lighting which is suitable for wet locations. Please refer to products HLG-40H-12, HLG-40H-24

Unit suitable to be setup in a camper to run lights and fridges along with other 12V appliances

Please refer to product Power Supply 240Vac input 12 Vdc 25 Amp - product code SP320-12

Unit suitable for a winch that draws 8 amps approx., operated by a 12v battery

You could use an RS series without charge control and set to 13.8 volts or a full PB series battery charger. In both solutions the battery must be connected to the power supply at all times to support the power supply to overcome inrush current of the winch motor on startup. The Ah rating of the battery should also be considered in both solutions. Please refer to Power Supply 240Vac input 15 Vdc 10 Amp - product code RS150-15

Power Supply 240VAC to 30VDC3A

Power Supply 240Vac input 27 Vdc 5.6 Amp SP150-27 can be turned up to 30VDC

Power Supply 27VDC Output - 60A - 230VAC Input - 50Hz

Please refer to Power Supply 240Vac input 24 Vdc 100 Amp product code RSP2400-24

Can the SP240-24 power supply be run continuously?

It is a common non-prescribed industrial power supply. It can run continuously as long as its operating within its specification and in a cool clean air environment.

Heat, dust and a humidity are killers for a fan cooled PSU's like the SP-240 series. Muck turns into mud inside mixed with a bit of humidity, not so great for high voltage switch-mode.
Keep it cool and dust free and it should run 24/7.

Types of inverters

There are several different types of inverters available. The most common types are pure sine wave or modified sine wave. A pure sine wave inverter produces an output waveform that is the same as a domestic power outlet. They are more difficult to manufacture and are the more expensive type.

Power ratings

In addition to the output waveform, inverters also carry a power rating. This indicates the amount of power the inverter is capable of delivering. Most inverters will have a continuous rating and a surge or peak rating. The continuous rating indicates the power level it is capable of delivering under sustained use without overload. The surge or peak rating refers to a level that can be delivered for short periods. How long the inverter is capable of delivering its surge rated power output for will vary from one manufacturer to another.

Important Safety Instructions for Inverters

General Safety Precautions

  • Do not expose the Inverter to Rain, snow, spray or excessive dusty conditions. To reduce the risk of hazard, do not cover or obstruct the ventilation openings. Do not install the Inverter in a zero-clearance compartment as overheating may occur.
  • Inverters contain components which can produce arcs or sparks. To prevent fire or explosion do Not install in compartments containing batteries or flammable materials or in locations which require ignition-protected equipment. This includes any space containing gasoline-powered machinery, fuel tanks, or joints, fittings, or other connection between components of the fuel system.
  • Ensure the existing wiring is in good electrical condition, and that the wire size is not undersized.
  • Inverter Cable & Accessories Guide
  • 12 Volt to 240 Volt Inverter

Types of batteries

Not all batteries are created equal. They are manufactured differently for different purposes.

Automotive batteries

Modern car batteries are designed to supply a surge of high current to crank the engine of a car. This is achieved by manufacturing the battery with a large number of thin plates to maximise the surface area of the plates. The plates are composed of a lead "sponge", similar in appearance to a very fine foam sponge. If subjected to deep discharge, this sponge will quickly be consumed and fall to the bottom of the cells. Automotive batteries should never be discharged by more than about 30% before recharge. A car battery will only last about 30 deep cycles, while they may last for thousands of cycles in normal starting use (2-5% discharge). Automotive batteries are rated in Cold Cranking Amps (CCA). This is the amount of current that the battery is able to supply for 30 seconds at -20°C while maintaining a terminal voltage of a 7.2 volts or more.

Deep-cycle batteries

The major difference between a true deep cycle battery and other types of batteries is that the plates are solid lead. They are manufactured with much thicker plates in each cell and can be discharged as much as 80% or more. Deep-cycle batteries are rated in amp-hours (AH): this means the current that can be drawn from the battery for a specified time, for example, a battery rated at 50 AH is able to supply 1 amp for 50 hours, or 2 amps for 25 hours and so on. This only works up to a point, as there are constraints on the maximum performance.

Note: There is no direct correlation between CCA and AH - one can not be calculated from the other

Marine batteries

Marine batteries are manufactured with thick plates in their cells to facilitate deeper discharges and are also rated in amp-hours. Most marine batteries are not true deep-cycle, but a type of hybrid. Most marine batteries may be safely discharged up to 60% before recharging.

Caution: Check with the battery manufacturer for recommendations of discharge rate. The information supplied should be used as a guide only.

Other types of batteries

AGM, or Absorbed Glass Mat

A newer type of sealed battery uses Absorbed Glass Mats, or AGM between the plates. This is a very fine fibre boron-silicate glass mat. These batteries have all the advantages of gelled batteries, but can take much more severe use. The plates in AGM batteries are tightly packed and rigidly mounted, and will withstand shock and vibration much better than any conventional battery.

AGM batteries have several advantages over both gelled and flooded batteries, at about the same cost as gelled batteries:

  • Since all the electrolyte is contained in the glass mats, they cannot spill, even if broken. This also means that since they are non-hazardous, the shipping costs are lower. In addition, since there is no liquid to freeze and expand, they are practically immune to freezing damage.
  • The charging voltages are the same as for any standard battery - there is no need for any special adjustments or problems with incompatible chargers.
  • AGM batteries have a very low self-discharge - from 1% to 3% per month is typical. This means that they can sit in storage for much longer periods without charging.

Gelled electrolyte

Gelled batteries, or gel cells contain acid that has been "gelled" by the addition of silica gel, turning the acid into a solid mass that looks like thick jelly. The advantage of these batteries is that it is impossible to spill acid even if the battery is broken. A disadvantage of gel cells is that they must be charged at a lower voltage than flooded or AGM batteries. If overcharged, voids can develop in the gel which will never heal, causing a loss in battery capacity. In hot climates, water loss can be enough over 2-4 years to cause premature battery death.

Battery Maintenance

Lead-acid batteries are perishable. During the discharge process, soft lead sulphate crystals are formed in the pores and on the surfaces of the positive and negative plates inside the battery. This creation of hard crystals is commonly called lead sulphation and it accounts for over 80% of deep-cycle battery failures. The longer sulphation occurs, the larger and harder the lead sulphate crystals become. The positive plates will be light brown and the negative plates will be a dull, off-white colour. These crystals lessen a battery's capacity and its ability to be recharged. Recharge as soon after discharge as possible, and if the battery is to be stored for more than two weeks, top up the charge frequently. This is the best way to prevent sulphation.

  • Add a battery conditioner in accordance with the manufacturer's instructions. This is a chemical additive, which prolongs battery life.
  • Alternatively use a "BATMAX" Ô Battery Maximiser. This simply attaches to your battery and removes lead Sulphate build-up and extends the life of your battery.
  • Check electrolyte levels regularly and top up only with demineralised water as required.
  • Buy a hydrometer and check the specific gravity of the electrolyte in each cell of the battery. This will detect damaged or collapsed cells before they leave you stranded with a useless battery.

Storing a battery

  • If the battery has filler caps, check the electrolyte level in each cell. If required, add only Demineralised water to the recommended level, but do not overfill.
  • Clean the top of the battery and the terminal posts.
  • Fully charge the battery.
  • Store it in a dry, cool place (above freezing), where it can be easily recharged.
  • Most importantly, prevent sulphation by keeping the battery charged at 100% state-of-charge level By frequent recharging. Once every two weeks is recommended.
  • Use a "BATMAX" Ô battery maximiser.

Caution: Always check with the battery manufacturer for charging instructions. Damage to the cells or reduction in service life may result from incorrect charging.

Precautions when working with Batteries

  • If battery acid contacts your skin &/or clothing wash immediately with soap and water. If acid enters the eye, immediately flood eye with running cold water for at least 20 minutes and get medical attention immediately.
  • Never smoke or allow a spark or flame in vicinity of battery or engine.
  • Do not drop a metal tool on the battery. The resulting spark or short-circuit on the battery or other electrical part may cause an explosion.