Battery Selection

How do I select the right battery for my application?

Proper battery selection may require the assistance of a knowledgeable battery sales/service technician. Please contact your local Enirgi Power storage outlet on 1300 783 879 and ask for assistance from one of our friendly staff.

What is the difference between a deep cycle battery, a starting battery, and a dual-purpose battery?

A deep cycle battery has the ability to be deeply discharged and charged many times during its service life. It is designed specifically for powering electrical equipment for long periods of time. An automotive or starting battery is designed for brief bursts of high current and cannot withstand more than a few deep discharges before failure. This is why it is unable to start your car if you accidentally leave the lights on more than a couple of times. For applications where both engine starting and light deep cycling are required, a dual-purpose battery is often used. This type of battery is neither a starting nor a deep cycle battery but rather a compromise between the two so it performs both functions adequately.

Can I use my Deep Cycle battery as a starting battery?

Deep cycle batteries can be used for engine starting but starting batteries should not be used for deep cycle applications. A deep cycle battery may have less cranking amps per kilogram than a starting battery, but in most cases a deep cycle battery is still more than adequate for the purpose of starting an engine.

What are the advantages and disadvantages of gel, AGM, and flooded lead acid deep cycle?

Generally, gel and AGM cost about two times more, and have a shorter cycle life than comparable flooded lead acid batteries. However, Gel and AGM batteries do not need watering, are safer (no acid spilling out), can be placed in a variety of positions, have a slower self-discharge characteristic, and are more efficient in charging and discharging than flooded batteries. Gel batteries are more suitable for heavy deep cycling applications whereas AGM batteries are more for light to medium cycling and engine-starting applications.

Battery Charging

How can a battery’s state of charge be accurately measured?

The state of charge of a lead acid battery is most accurately determined by measuring the specific gravity of the electrolyte. This is done with a hydrometer. 

Battery voltage also gives an indication of the level of charge when measured in an open circuit condition. This should be done with a voltmeter. For an accurate voltage reading, the battery should also be allowed to rest for a period of at least 3 hours to let the voltage stabilise.

Does my deep cycle battery develop a memory?

Lead acid batteries do not develop any type of memory. This means that you do not have to deep discharge or completely discharge a battery before recharging it. For optimum life and performance, we generally recommend a discharge of 20 to 50% of the battery’s rated capacity even though the battery is capable of being cycled to 80%.

Do batteries self-discharge when not in use?

All batteries, regardless of their chemistry, self-discharge. The rate of self-discharge depends on the type of battery, the age of the battery, and the storage temperature the batteries are exposed to. As an estimate, batteries self-discharge approximately 4% per month at 27°C.

What size charger should I buy?

A properly sized charger takes into account battery capacity and the time interval between charges. In applications where cycling is infrequent, such as weekend caravan users, or infrequent or seasonal trolling motor usage, a charger with an output current rating between 10 and 13% of the battery's rated 20-hour capacity will suffice. In applications where battery recharge must be accomplished within 8 to 10 hours, a three stage, automatic charger, rated at 20% of the battery capacity, may be required. Example: A good charging rate for a battery with a 20-hr capacity of 225 amp-hr is about 22 to 29 amps. You can of course go slightly higher or lower depending on what is available on the market.

Battery Maintenance

How can I tell if a battery is bad?

To determine if the battery system is experiencing a problem, fully charge the batteries then shut off the charger and remove all electrical loads. Allow each battery in the system to stand on open-circuit for about one hour. Measure the voltage of each battery. If the battery voltage spread exceeds 15 volts for a 6 volt battery, or .30 volts for a 12 volt battery, a problem is indicated. Battery voltage alone does not confirm a problem. When the voltage spread indicates a problem, confirmation is accomplished by taking electrolyte specific gravity readings using a hydrometer. If the specific gravity readings show a spread greater than .030 (30 points), give the batteries an equalisation.

What is used to clean a battery and neutralise the electrolyte?

A solution of baking soda and water. Use 1 lb of baking soda for every gallon of water.

Battery Recycling

Are lead acid batteries recyclable?

Lead acid batteries are 97% recyclable. Lead is the most recycled metal in the world today. The plastic containers and covers of old batteries are neutralized, reground and used in the manufacture of new battery cases. The electrolyte can be processed for recycled waste water uses. In some cases, the electrolyte is cleaned and reprocessed and sold as battery grade electrolyte. In other instances, the sulfate content is removed as Ammonia Sulfate and used in fertilizers. The separators are often used as a fuel source for the recycling process.

Where do I recycle my junk batteries?

Contact our national collection service on 1300 783 879, book a collection online or drop your used batteries into an Enirgi Power Storage outlet.

Battery Temperature

How does temperature affect the performance of my batteries?

At higher temperatures (above 25°C) battery capacity generally increases, usually at the cost of battery life. Higher temperatures also increase the self-discharge characteristic. Colder temperatures (below 25°C) will lower battery capacity and prolong battery life. Cooler temperatures will slow self-discharge. Therefore, operating batteries at temperatures at or slightly below 25°C will optimize both performance and life.

How do I account for temperature when taking my voltage readings?

Temperature will affect voltage readings. As temperature increases, voltage decreases. Conversely, as temperature decreases, voltage increases.

Is there a maximum temperature for charging my batteries?

When charging lead acid batteries, the temperature should not exceed 45°C. At this point the battery should be taken off charge and allowed to cool before resuming the charge process.