Differences between AGM, Semi traction and GEL batteries
The most commonly used (household) batteries in campers, caravans and maritime applications are the so-called lead-acid batteries. There are various types of these batteries, but before we tell you more about them, let's first look at what similarities lead-acid batteries have. Lead-acid batteries all use an electrolyte consisting of battery acid and plates made of lead to store electrons through a chemical process. These batteries use multiple cells to achieve a sufficiently high energy density. Lead-acid batteries store a relatively large amount of energy in a relatively small housing for a relatively long time. This makes this type of batteries very suitable for use in a camper, boat or caravan and in combination with solar energy.
What makes these batteries different?
Although all AGM, Gel and Semi traction batteries contain lead-acid, the internal construction determines what type of battery it is. AGM stands for Absorbed Glass Mat Technology. AGM batteries use fiberglass mats as a separator between the battery plates to store the electrolyte. This electrolyte is trapped here by the so-called capillary effect. The advantage of AGM batteries is that they are completely closed and therefore cannot leak. Another advantage of this technique is that the internal resistance of an AGM battery is low, resulting in an easy to charge battery and less loss during discharging of the battery because less heat is released. AGM batteries have a very low self-discharge of approximately 3% per month. When a 110Ah AGM battery is stored fully charged, it will still have approximately 76Ah of charge left after a year. The AGM batteries we sell use a recirculation system called VRLA (Valve Regulated Lead-Acid). This means that the gases generated during charging are converted back into liquid. This ensures that the batteries last even longer. AGM batteries have the highest energy density compared to GEL and Semi Traction. When deeply discharged to 50%, this type of battery lasts approximately 700 charging cycles. All these properties make this type of battery most suitable for use with a wind or solar panel system.
Gel batteries
are closed (sealed), just like AGM batteries, so the similarities end there. Gel batteries use silica (sand) to turn the battery acid present into a thick gel. This gel is used in the battery as an electrolyte. Gel batteries must be prevented from ending up in situations where high charging or discharging currents arise. A high discharge current occurs, for example, when you make a cup of coffee with your Senseo that is connected to the battery via your 2000W inverter. High currents can literally cause the GEL to rupture and leave air pockets behind, which causes the plates to corrode more quickly, eventually leading to a defective battery. It is therefore not recommended to use GEL batteries that require high charging or discharging currents; it is better to use the AGM or Semi Traction battery. Gel batteries have a stronger construction than Semi Traction batteries, but not nearly as strong as AGM batteries. GEL batteries have a very low self-discharge of approximately 2% per month. When a 110Ah GEL battery is stored fully charged, it will still have approximately 86Ah of charge left after a year. Gel batteries are sensitive to overcharging, which causes permanent damage. When deeply discharged to 50%, this type of battery lasts approximately 900 charging cycles.
Semi traction or wet cell batteries
are the most commonly used batteries in the market. They come in many shapes and sizes and are used for many applications. Just like AGM batteries, Semi Traction batteries have lead plates, battery acid as electrolyte and a separator between the plates, this is where the similarities end. Semi traction batteries are usually not closed (sealed) and the generated gases are not reused. The generated gases are often vented outside, which means that these batteries require maintenance such as adding water to replace the gasified electrolyte. Steam, condensation and battery acid can also pass through this same valve. If you do not perform timely maintenance on this type of batteries, the plates come into contact with the atmosphere and begin to corrode, resulting in reduced power and ultimately a defective battery. Semi traction batteries hold a lot of energy for a reasonable price, but they require more work to keep them in top condition. Semi traction batteries have the weakest internal construction and also the most internal resistance. Semi traction batteries have a high self-discharge of approximately 6% per month. When a 110Ah Semi Traction battery is stored fully charged, it will still have approximately 52Ah of charge left after a year. When deeply discharged to 50%, this type of battery lasts approximately 500 charging cycles.
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