## 1 Introduction
In [3], the simulation of a hybrid microgrid located in Colombia obtained lower NPC and LCOE with Li-ion batteries. In [27], the redesign of an existing rural microgrid located in a small island in Thailand was addressed, proposing and comparing three hybrid solutions with Li-ion batteries and one with lead-acid battery. The lowest cost was obtained with Li-ion batteries, although at the expense of higher fuel consumption. In [28], the case study is located in Tanzania and in the home solar system, Li-ion batteries obtained a lower LCOE. In [29], the case corresponds to a small DC load located in India and the study resulted in the use of a Li-ion battery. The four case studies of [30] are also located in India, where for both types of battery, the proposed systems included the same generation power. Therefore, the effect of battery type on system size was not considered. In [31], a case study in North Korea offered better economic results with lead-acid batteries, although close to those of Li-ion batteries. In [32], the case study is located in Malaysia and a lead-acid battery proved to be the most profitable option. In addition to standalone PV systems, the combined use of PV generation and batteries is frequent in microgrids. A microgrid is a small energy distribution system with generation, storage, loads and usually an EMS (Energy Management System), which depending on its architecture and mode of operation can work connected to the network or disconnected from it [33]. When it operates in islanded mode, the function and requirements of its batteries are similar to those of standalone systems. Moreover, stationary lead-acid or Li-ion batteries can operate as a buffer in those cases where it is necessary to charge the Li-ion batteries of electric vehicles taking advantage of the stored energy of PV origin [34]. It is well known that in electric vehicles, the characteristics of Li-ion batteries are much more suitable than those of lead-acid ones but, in stationary systems, lead-acid batteries could be used if its technical and economic performance is considered adequate. Another characteristic that differentiates both types of batteries is the greater management complexity of Li-ion batteries, which require additional electronics and management algorithms [35; 36]. This can lead to incompatibilities between batteries from different manufacturers and raise the design and maintenance costs of the systems. The additional circuitry also drains small currents that increase self-discharge. In summary, more than a controversy, currently the choice of one battery type or another depends on each case that is addressed, and the criteria applied to make the decision. In the absence of detailed studies, in practice general criteria or preferences are applied that do not ensure the best choice, since both technologies offer acceptable results in PV standalone systems. In fact, both lead-acid and Li-ion batteries are being installed in new standalone renewable energy systems. The general expectation is that Li-ion batteries will lower their prices and prevail. However, despite the increase towards mass production, the price reduction of Li-ion batteries is not guaranteed. Its characteristics make it the option for electric vehicles, which can dramatically increase its demand and hinder price reductions. For this reason, it cannot be ruled out that in standalone renewable energy systems, lead-acid batteries still have a future. As an alternative, the use of Li-ion batteries recycled for a second life is also being considered in standalone systems [37] and other stationary applications [38]. This work seeks to better understand the technical and, above all, economic implications of using Li-ion batteries instead of lead-acid in standalone renewable energy systems. With this objective, the study presents various novelties. First, it focuses on the simultaneous study of five cases whose main difference is the consumption profile.