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How to know what capacity and what type of batteries is the most convenient in each case?

Solar energy batteries are used to store the electrical charge collected by the photovoltaic modules and that will be used to supply the consumption of an installation, supplying it regardless of whether the panels are collecting energy at that precise moment.

How to know what capacity and what type of batteries is the most convenient in each case?

Depending on the type of photovoltaic installation, the battery must meet certain technical requirements for discharge cycles, storage volume, performance, durability and maintenance. We review the different existing types.

Types of batteries in isolated solar installations

Although there are more and more options in lithium batteries, at the moment their high price and their features make them more advisable in grid connection applications, therefore in this article we are going to focus on the most used batteries in isolated solar installations that are those of lead-acid thanks to their great value for money, offering a very good storage capacity.

stationary batteries

Here we distinguish the OPZS, OPZV and TOPZS models, batteries made up of independent 2V cells and with a maximum charge capacity of 4500Ah. The most used batteries are those that range between 300Ah and 1500Ah, adapting very well to all kinds of personal needs for electricity consumption. The vessels are joined together using semi-rigid bridges and are all connected in series to form 12V (6 vessels), 24V (12 vessels) and 48V (24 vessels) systems.

OPzS batteries are 2V cell batteries that are liquid lead-acid, OPzV are lead-acid batteries in GEL form, more commonly called GEL batteries, and TOPzS batteries are batteries very similar to OPzS but of manufacturing with cheaper materials, which gives them a shorter useful life, which means that normally due to their little difference in price compared to OPzS, they are not a highly recommended option.

The OPzS solar battery is the most used in both small, medium and large installations for daily use, with a durability of up to 20 years, in addition to optimal performance in continuous charge and discharge cycles.

monobloc batteries

Indicated for low and medium power solar installations and above all recommended for sporadic or weekend use. The most popular monoblock batteries are those that range between 100Ah and 250Ah.

You can find 6v and 12v monoblock batteries to supply a large number of devices. Normally they are not recommended for daily use since due to the useful life cycles that this type of battery can offer, in daily use they would not last more than between 1 and 2 years or at most 3 and for this reason it is always recommended for daily use. OPZS batteries that can last up to 20 years. Today for low power installations there are also VRM model Hoppecke AGM monoblock batteries that can offer a useful life of up to 15 years in daily use.

Liquid acid monoblock batteries have the appeal of being very cheap and affordable for all types of pockets and have a maximum useful life or durability of between 3 and 5 years, although they require periodic maintenance such as adding distilled water from time to time and Depending on their use, they also require periodic equalization charges.

Gel and AGM monoblock batteries are recommended for any type of use, these batteries withstand high energy peaks and have a maximum durability of between 7 and 10 years. They are manufactured in a monoblock format with the difference that they do not require maintenance and their durability is slightly greater than those of liquid acid.

Required Capacity

As a general rule, the daily consumption that our solar installation is going to have must be calculated and to maximize the useful life of the lead-acid batteries, it is recommended to install a set of batteries that allows the accumulation of between 4 and 5 times the power necessary for the consumption of a day of our installation. With this rule we achieve that, as a general rule, in a day of consumption the batteries cannot be discharged more than 20-25% and therefore we have about 2-2.5 days of autonomy without discharging the batteries more than 50% of their capacity. ability.

If we want to extend the useful life of lead batteries, we should always work with the batteries at a charge level above 60% and we should never discharge them below 20% of the remaining charge, since if we discharge completely a lead battery we can even damage it.


All the batteries can be installed with each other connected in series, to increase the operating voltage of the set, or in parallel, to increase the intensity in amps that we can store and supply, but maintaining the same voltage (12, 24 or 48Vdc is most common).

Find in our store the models of solar batteries that best adapt to your solar installation, whatever its capacity. We have a wide range of battery types with which to take advantage of all the solar energy to save on your electricity bill and enjoy more responsible consumption.