How to take care of your AGM Deep Cycle Batteries

Top tips from industry insiders and manufacturers.

With sealed construction and a designed service life of seven - ten years, AGM deep cycle batteries require very little maintenance, especially when compared to their flooded cell counterparts. Nevertheless, knowing how to correctly charge and look after your deep cycle battery is crucial in optimising its performance and life span.

To help you get the best out of your deep cycle battery, we’ve put together a guide to charging and maintenance. Still got questions? Click the contact us tab and fire away!


Never store your battery in a discharged state, this can cause sulfation (see below) and make it difficult to recharge the battery fully. Keep your battery in a cool and dry place with plenty of ventilation and remember to recharge if storing for more than four months.

Preventing Sulfation

Sulfation occurs when the sulfuric acid within lead-acid batteries reacts to form a lead sulfate on the battery’s negative plates. The surface area of the acid on the plates is reduced, making it hard for the battery to hold its charge. The best way to prevent sulfation is by charging your battery before storage. If it’s too late for that, try using a reverse pulse desulfation charger such as the 12V 8A Automatic Reverse Pulse deep cycle battery charger. The specialised battery charger can reduce effects of sulfation by using reverse pulse technology to limit the battery’s internal impedance while charging.

Charging Your Battery

Correctly charging your deep cycle AGM battery is crucial in maintaining performance. Overcharging your battery can damage the internal structure of the battery while undercharging can shorten its lifespan. The trick is to find the correct voltage for your battery, which in the case of AGM deep cycle batteries, is 14.7v. 

While it is possible to charge your AGM deep cycle battery using a traditional petrol generator, most have insufficient regulators and can damage your battery. For safe and effective charging, use the iTechworld 20Amp 240v battery charger or consider using an iTechworld solar system with regulator for a cleaner power option.


Using a Battery Charger

A 240v ‘smart’ charger, such as the iTechworld 20Amp 3 Stage deep cycle battery charger is a great tool to accurately charge your deep cycle battery. The new devices automatically detect the type of battery being charged by sending a pulse into the battery to determine its internal resistance. It can then decipher the voltage that best suits that type of battery, meaning you don’t need to worry about overcharging or even removing the battery from the charger when it’s finished.


Charging From Solar

For cost effective and environmentally friendly power, consider using an iTechworld solar system to charge your AGM deep cycle battery. This method is especially useful for motor home or caravan owners who are without access to grid power but do have portable solar panels. After placing the solar panels in the sun, the power they produce can be run through a regulator set to charge AGM deep cycle batteries. While the fluctuation in power levels of 12v solar panels would damage a battery if left unregulated, using a regulator such as the iTechworld intelligent Solar Charge Regulator ensures the correct voltage is consistently fed into the battery.



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