When you are on the look-out for the right battery for your system, keep in mind that deep-cycle batteries are not all the same. No single design of battery is suitable for all applications, so it is important to know what kind of battery you need.
In this article, we will discuss the available types of deep-cycle batteries so that you will be able to choose the correct type of battery for your particular application.
There are two primary categories of batteries available: Flooded and Valve-regulated Lead-Acid (VRLA), which is subdivided into two types; Absorbed Glass Mat (AGM) and gel.
The flooded lead acid battery is the most popular and in-demand type of battery on the market these days. This battery has vents that are removable so that you can check the specific gravity of the acid with a hydrometer. You can then add distilled water regularly, which is usually required once a month.
Since it is not sealed, it is made to release the hydrogen and oxygen gas that is created during the charging process, and because of this, the battery bank should be properly expelled outside. If this is not done, there is a high risk that the oxygen and hydrogen will react and ignite. A specialized battery vent fan is recommended to assist in safely moving the gasses out.
One great advantage of these deep-cycle flooded batteries is that they come at a lower cost than the sealed deep-cycle VRLA batteries. When the flooded type of battery is well-maintained, it generally has a longer lifespan than the other types.
This battery also has a high discharge rate capacity and it performs better in hot climates. In terms of availability, it is easier to find this type of battery worldwide because it has a long and proven history of use.
As for the disadvantages, some people see the periodic maintenance of adding distilled water as a hassle. It is also less flexible than the VRLA batteries because it can only be used in an upright position, requires good ventilation, produces gas when charging, and may emit acid spray if overcharged excessively.
It can also be quite limiting in terms of application because it cannot be shipped by air due to its classification as a hazardous material, and cannot be used in near electrical equipment or anything that is highly flammable.
To summarize, this deep-cycle flooded battery’s versatility makes it the lead choice for renewable energy systems in cases where regular maintenance can be done and good ventilation is not an issue.
The sealed lead acid battery is generally better-known as either Advanced Glass Mat, AGM battery, or Gel battery. These terms refer to the form of the electrolyte used.
In AGM batteries, the electrolyte is placed in a spongy mat, while in Gel batteries, there is a thick gel that keeps itself evenly distributed within the battery. In general, both types are very similar, and they only have slightly different pros and cons.
Because these batteries are sealed, their greatest advantage is that they are safe from spillage and outgassing. They are also maintenance free, and all you need is an occasional inspection to check their condition.
These sealed batteries are a great choice for backup systems that are not charged and discharged daily and have a long standby period. They are also accessible because they are easily shipped as a non-hazardous material, and do better in extremely cold temperatures.
The downside to these sealed batteries is that they are more expensive than the flooded battery, and they also tend to have a shorter lifespan than a well-maintained flooded battery. If you are the type who does not like the hassle of having to regularly maintain equipment, this sealed type is a perfect choice.
This type of battery was developed in the late 1960s to eradicate the hassles of water addition and to provide batteries that are more flexible for use in a wider range of applications and different positions. Deep cycle AGM batteries are generally cheaper than deep-cycle Gel batteries.
Among the deep-cycle battery types, the AGM battery has the best capacity for high power applications, the lowest self-discharge rate, and the best shock-resistance. This battery can also withstand a wider range of temperatures than the other types.
For systems that require regular deep discharge, these batteries do not perform as well as deep-cycle flooded or gel batteries.
The Gel battery performs better than deep-cycle AGM batteries for low power applications and for systems requiring regular deep discharge.
This battery tends to be more expensive than the other types and does not perform as well as the others in cold temperatures and in cases when a shallow depth of discharge is reached regularly. The Gel battery also has a higher self-discharge rate than AGM batteries.
Originally posted 2017-07-05 07:45:12.