Since the invention of lead-acid batteries, many decades have passed, yet they are still widely used across various industries. Naturally, the technology has evolved over time due to improvements in chemical composition and design, but the fundamental principle remains unchanged: lead plates (with or without antimony) and an acid electrolyte are still at the core of their operation.
Today, AGM batteries are among the most popular types. AGM (Absorbed Glass Mat) is a technology that utilises a gel-like electrolyte and special fibreglass separator plates. These plates effectively retain the electrolyte, ensuring improved performance and longevity.
Advantages of AGM Batteries
As we previously mentioned, the construction of an AGM battery is similar to the traditional design, but has some key differences. In particular, the use of tightly packed fibreglass separators and a sealed casing significantly enhances its performance. It is important to note that the specifications of AGM batteries can vary considerably depending on the technologies and materials used. Therefore, before purchasing, it is essential to carefully examine the features of the chosen model to ensure it meets your requirements.
Key Advantages and Features:
- High resistance to deep discharges
Any battery suffers from deep discharge, especially if left in that state for a prolonged period. AGM technology is significantly less susceptible to this phenomenon. It allows the battery to discharge up to 50% without significant losses, whereas traditional lead-acid batteries can only withstand 30%. This makes AGM an ideal solution for cyclic operation. - Sealed and safe design
AGM batteries feature a sealed, valve-regulated casing, allowing them to be used in any position (except upside down to prevent safety valve blockage). Since there is no electrolyte leakage, these batteries are safe for use in residential areas, vehicles, and industrial applications. - Maintenance-Free operation
AGM batteries require no maintenance throughout their entire service life. Thanks to gas recombination within the porous glass fibre separators, there is no need to add water. This is a crucial advantage for backup power systems, where selecting a reliable and autonomous energy source is essential. - Protection against sulfation and corrosion
The absence of vapours positively affects the longevity of lead plates. AGM batteries have significantly lower susceptibility to sulfation, which extends their lifespan. As a result, they maintain their efficiency 30-50% longer than conventional lead-acid models. - High resistance to vibrations and mechanical stress
Thanks to the glass fibre separators that securely hold the electrolyte in place, AGM batteries demonstrate excellent resistance to shocks and vibrations. This makes them an ideal choice for cars, motorcycles, yachts, and other vehicles, as well as for industrial applications.
The Absorbent Glass Mat (AGM) technology offers several advantages, including high capacity, rapid recharge, and enhanced resistance to vibrations. However, it is also important to consider certain drawbacks. The primary disadvantage is its sensitivity to incorrect charging.
To ensure maximum longevity of an AGM battery, it should be charged in the correct mode with minimal deviations. Using makeshift methods or low-quality chargers can significantly shorten the battery’s lifespan. It is recommended to use only automatic chargers specifically designed for AGM batteries to prevent premature wear and ensure stable performance.
AGM Battery Usage Rules: How to Extend Their Lifespan
AGM batteries offer numerous advantages: they are maintenance-free, resistant to vibrations and leaks, and provide stable performance. However, to maximise their efficiency and longevity, it is essential to follow proper usage guidelines.
- Avoid Deep Discharges
- Critical limit: regularly discharging more than 30% of the battery’s capacity can significantly shorten its lifespan.
- Optimal operation: AGM batteries are particularly sensitive to deep discharges in cyclic use, so it is best to maintain a charge level of 70-80%.
- Follow the Correct Charging Regimen
- Optimal current: after discharge, the battery should be recharged at a current of 1/10 of its capacity for 10 hours.
- Avoid overheating: incorrect charging can cause overheating and degradation of the battery plates.
- Use Modern Charging Devices
- Automatic regulation: it is recommended to use chargers with automatic current and voltage adjustment.
- Temperature adaptation: some models can adjust based on battery temperature, helping to extend its lifespan.
By following these simple guidelines, you will ensure maximum performance, operational stability, and longevity for your AGM battery.
FAQs
How many cycles can an AGM battery withstand?
AGM (Absorbent Glass Mat) batteries typically last between 300 and 1,300 charge-discharge cycles, depending on quality, operating conditions, and depth of discharge.
Approximate cycle life:
- Deep discharge (up to 80%) – 300–500 cycles
- Moderate discharge (up to 50%) – 600–800 cycles
- Shallow discharge (up to 30%) – 1,000-1,300 cycles
A high-quality AGM battery from reputable brands (such as Varta, Exide, or Optima) may offer an even longer lifespan, especially with proper maintenance (charging at 14.4-14.8V and avoiding deep discharges).
Can you jump start an AGM battery?
Yes, you can jump-start an AGM battery like a standard lead-acid one. Use a compatible jump starter or another vehicle with a matching voltage (12V for most AGM batteries). Connect the cables correctly—positive first, then negative to a grounding point. Avoid overvoltage by using a smart charger with an AGM mode if possible. After jump-starting, fully recharge the battery with a proper charger (14.4-14.8 V). If the battery frequently needs a jump start, it may be time for a replacement.
