Solar batteries are used in conjunction with solar power panels and are usually stored in enclosed locations where venting may not be an option. In this case you would require a virtually maintenance-free type of battery that offers an extremely low chance of mishap. Solar panels are often times mounted in difficult to access or remote locations and you want a battery for your application that will survive the elements and last a long time. So what type of battery do we recommend for use with solar panels? Sealed AGM!
AGM stands for absorbed glass mat. These batteries evolved from gel-type batteries. The glass mat is actually a Boron-Silicate glass mat that is really fine and this glass mat is about 95% absorbed with the electrolyte. Because the electrolyte is absorbed in the glass mat, if the battery is broken, there won’t be any caustic and dangerous leaks. So in actuality, AGM batteries are non-toxic and extremely low maintenance. The reason why flooded batteries are higher maintenance is because you have water loss due to electrolysis. With AGM batteries there is virtually no water loss, which makes the efficiency of these batteries incredibly high – almost 99%.
Some pro’s to AGM batteries are that the voltages are the same as any other battery so any charger – in this case, solar – can be used. Additionally, heat levels during heavy load (like when everything in the house is on) remain low, which mitigates fire hazards. Storing AGM batteries is also a cinch, they’ll discharge themselves at a very low percentage per month (less than 5%) and in the event that they are completely discharged, are capable of being recharged to almost full capacity. NOTE: NEVER DISCHARGE A BATTERY OF ANY TYPE COMPLETELY. Also, if you’re concerned about fluctuating temperatures AGMs are not as susceptible to frozen conditions as other types of batteries.
Really the only downfall to having an AGM battery for solar applications is that they are more expensive than other types but the low maintenance and long life will offset the higher cost in no time.