Analyzing and designing energy storage system and charging station from solar energy-lithium ion

This paper presents the design of a battery charging center that will be used optimally by students in the Department of Electrical Engineering, Ambon State Polytechnic (POLNAM, Politeknik Negeri Ambon ). This study would like to design a charger station with a load requirement of 145.98 Wh that can be used as a blueprint for future relevant programs. The design of the charger station is based on the results of research that has been conducted in the study. The results of this study have shown that the number of solar panels 100 WP as much as 1 piece, BMS capacity (ICh = 11.6 A and IDch = 31.7 A), SCC capacity 6.125 A 10 A, Inverter 261 Watt 0.5 KW, and battery pack 21.75 Ah. This is an open access article under the CC BY-SA license.


METHOD Solar Panel
Solar panels are made flat and rectangular from several interconnected solar modules.These photovoltaic cells are made from silicon materials.When sunlight hits a solar cell, photons carried by sunlight knock electrons on the silicon wafer.A solar cell consists of two layerspositive and negative that already exist allowing the flow of electricity.When many photovoltaic cells are connected together, solar panels are formed.Each photovoltaic cell generates electricity and hence many modules in the panel are combined to make electricity output current and voltage (Hargroves, 1983;Rout et al., 2015;Tirmare & Khandare, 2015).
The type of solar panel used in this study was monocrystalline.This type of solar cell uses pure silicon crystal rods.These pieces of solar cells are identical to each other so that they have a high level of efficiency (equivalent to 15-25%).Physically, this solar cell has a solid black color and there will be a cavity or empty part between one solar cell and another solar cell if arranged into a solar panel.This happens because the solar cells used are cut slightly at each corner and are round or rectangular in shape which can cause losses because of it.This can reduce the energy produced in this breed.The high price is also one of the considerations in choosing this type of solar cell (Dobrzański et al., 2013;Sofijan, 2020).The following are the specifications of the solar panels used:

Battery
Battery is an energy storage device that is able to convert chemical energy into electrical energy so that it can be used as an energy source in electronic devices (Diantari & Pujotomo, 2017).The use of batteries as energy storage devices is almost used in all electronic devices.With the battery, the use of electronic devices can be more efficient because they do not have to connect the device to a power source to activate it so that electronic devices can be used everywhere.The battery must have a large energydensity and power density (Rout et al., 2015).Lithium ion batteries are the most widely used energy storage technology today, especially for devices that use batteries as their main source.Lithium ion batteries can produce large energy and power densities, another advantage is high efficiency, without memory effects and relatively long life cycles (Otong, 2019).
LIB rechargeable batteries are a practical and easy solution that has been accessible for a long time, especially in electronic products such as mobile phones, laptops, and smart watches.Inside LIBs, lithium ions migrate in and out of the two interior electrodes (Wu et al., 2015).When discharging, the reaction mechanism at the anode is described in the following equation: xLi+ + 6C + xe− = LixC6 (Li et al., 2014).Although the main mechanism is clear, this is inevitable and troublesome side effects occur on electrodes and electrolytes.Such side effects cause problems in the following areas: chemical and physical stability, oxidation-reduction quality, decreased capacity, coulomb efficiency, expansion-shrinkage volume and cost.The classic rocking chair battery, in which lithium ions move continuously, is clearly presented Figures 1(a

BMS (Battery Management System)
Battery Management System (BMS) or battery management system is an electronic system that manages batteries.BMS systems are essential for monitoring parameters such as charge status, thermal condition monitoring, ampere hour calculation, terminal voltage and current flowing.BMS also helps in controlling or balancing the battery environment.BMS is used to keep every cell in the battery pack in a safe condition.BMS has an important role in improving battery performance and optimizing vehicle operation in a safe and reliable manner.BMS can be used to monitor the condition of the battery by the rider.So that the driver can find out the estimated mileage on the vehicle (Wahyudi et al., 2021).
The capacity of the BMS can be determined using the equation (2)

Inverter
Inverter is a power electronics circuit that has a function to convert or convert direct voltage (DC) into alternating voltage (AC) (Diantari & Pujotomo, 2017).That is why this power circuit is also called an inverter because it is in accordance with its function.Another function of this inverter is to regulate and make a stable voltage at the electrical output it produces.The type of inverter used is the type of Pure sine wave (PSW), has the characteristics of this wave works optimally on all electronic equipment because the waves produced are pure as waves generated from PLN.The advantage of this type of inverter is higher power efficiency because of less power consumption.

Solar Charger Controller (SCC)
SCC is a charge controller used in solar powered applications and is also called a solar battery charger.Its function is to regulate the voltage and current from the solar array to the battery to prevent overcharging and also overuse.There are many technologies that have been incorporated into the design of solar charge controllers.For example, the MPPT payload controller includes a maximum power point tracking algorithm to optimize PV production of cells or modules.The solar charge controller ± regulate the voltage and current coming from the PV panel towards the battery and prevent overcharging of the battery and extend battery life battery life (Diantari & Pujotomo, 2017).

Figure 3. Solar Charger Controller (SCC)
The amount of SCC used, can be calculated by the equation SCC = 1 solar panel x 4.90 A x 1.25 ( 5)

RESULTS AND DISCUSSION Electrical Power Consumption Requirement (Watt-Hour)
The need for electrical power at the charging station is determined based on the amount of electrical power in the electronic device being used and the length of time in its use (charging process).The devices used in this study are mobile phones with several types and laptops whose specifications can be seen in Table 2. below.The amount of electrical power required, in this study, is shown in Table 3 below

Battery Group/Cell for Series and Parallel Systems
Based on the results of the calculation of the needs of the pack battery, the composition of the battery pack assembly is 3 series and 19 parallel to get a voltage of 12 V 32 Ah.The arrangement of battery groups in series and parallel can be seen in Tables 5 and 6 below.

CONCLUSION
Based on the results of research that has been conducted in the design of the charger station, it can be concluded that to build a charger station with a load requirement of 145.98 Wh requires the number of solar panels 100 WP as much as 1 piece, BMS capacity (ICh = 11.6A and IDch = 31.7 A), SCC capacity 6.125 A 10 A, Inverter 261 Watt 0.5 KW, and battery pack with a capacity of 21.75 Ah.If assembled in 3 Series and 7 Parallel, it requires 31.85Ah≈≈.

Figure 2 .
Figure 2. (a) Schematic design of secondary Li-metal battery (picture of dendrite growth at Li surface was obtained directly from in situ scanning electron microscopy measurements).(b) Rechargeable Li-ion battery (Tarascon & Armand, 2001) Description and model of lithium ion batteries used in this study:

Table 1 .
Description and Model of Lithium Ion 18650 Battery

Table 2 .
Research Tools and Their Capacities

Table 3 .
Total Electrical Power Requirement used in Hours Solar panels to be used must be able to supply power continuously in accordance with the desired power needs.In this study, solar panels used had a capacity of 100 WP.If the power requirement to be used is 145.89Watt-Hours, then the number of solar panels used is

Table 5 .
Group Cell for Series System (3S)

Table 6 .
Group Cell for Parallel Systems (13 P)