Do You Know How To Get Cheap Lithium Batteries?

Every person who can’t afford the original expensive batteries looks for some alternative. You can scour the market and internet to look for some cheap batteries. Some people even find it. But the biggest question arises here is whether those batteries are safe·

Here, you will learn as much as you can about the cheap Lithium batteries.

Does Cheap Lithium Batteries Have Good Quality·

You might think buying the cheap lithium-ion batteries is a good thing to save money. But it raises another important question about their qualities. Once you go out in the market, you will find lots of batteries which are fake and potentially dangerous.

But the good thing is these cheap batteries sometimes have genuine quality. Sometimes, the scammers are pretty good at what they do. But if you are careful, you can really get your hands on cheap lithium batteries. Or you learn to make a battery pack yourself.

How To Choose Good Cheap Lithium Batteries·

To make sure that you are choosing a good quality cheap Lithium-battery, you have to verify the weight of the battery to the ones which are listed on the manufacturer’s website. Every manufacturer provides the ideal weight for the different types of batteries to various resources. So, you can check the original weight. And if the battery weighs the same as those of the batteries you are buying, it means you are actually buying a quality battery that will pay off.

How To Make An Inexpensive lithium-ion battery Pack·

From laptops to Drones, medical devices to power tools, e-bikes to electric cars, everything is becoming electric. And Lithium-ion batteries are the ones which are used in all these scenarios. Normally, the 18650 AA cells are used for various requirements. So, here we are going to learn how to make a battery pack using the 18650 cells in series and parallel. So, let’s start.

Step 1: Parts and Tools You Require:

Before we get to the integration part, it is vital that we go through the tools that are required for the pack. The parts we need include:

· 18650 battery

· BMS

· Ni Strips

· Battery Level Indicator

· Rocker Switch

· DC Jack

· 18650 battery holder

· 3M x 10 mm Screws

All these parts can be bought online or from any store close to you. Along with these parts, you will also need some tools like spot welder, 3D printer, Wire Stripper/Cutter, Hot Air Blower, Multimeter, and a Li-Ion Charger. And don’t forget the safety goggle and electrical gloves while you are at it.

Step 2: Select the Right Cells:

As you go out, you will see various types of 18650 cells in the market within your budget. You can buy them from branded companies which have brilliant characteristics and excellent quality control. Don’t consider buying cheap cells as they have a high risk of explosion and overheating during the charge and discharge. You can buy the cells with a capacity around 2000mAh to 4000 mAh.

Step 3: Choose the Right Battery Strips:

To connect the cells together, you will obviously need conductor strips. Ideally, you should purchase the Nickel strips or thick wire to do so as they are perfectly suitable for the job. You can choose either nickel-plated steel strips or pure nickel strips. The pure strips will cost you a little bit more but they also have lower resistance value which is good for our pack.

Step 4: Spot Welding and Soldering:

Spot welding is considered better from soldering as it enhances the chemical reaction which damages the cell. The reason to do spot welding is that it securely joins the cells without adding heat. You can use the hobby-grade spot welder from any online store and use it.

Step 5: Check the Cell Voltage:

Before you start connecting the cells with each other, it will be better to mark them and check their individual cell voltage. For parallel arrangement, the cell voltage should be close to each other otherwise the current flow will disrupt. This can damage the cells and results in a fire on rare occasions.

As long as the cell voltage is around 3.5 V to 3.7 V, you can join them together without any worry.

Step 6: Battery Back Capacity and Voltage:

To start making the battery pack, you first have to finalize the capacity and nominal voltage of the pack. It is important that you connect the cells in parallel to reach the desired capacity, and keep the series so that it will also have the desirable nominal voltage.

Step 7: Assemble the Cells:

Once you have determined how you need to arrange the battery pack, it is time to start assembling them. To make a pack of capacity 17000 mAh and a nominal voltage of 11.1 V, you have to make the pack with 3 parallel groups connected in series where each cell has the voltage of 3.7 V. And each parallel group will have 5 cells with 3400 mAh capacity. So, now, you have to arrange the 15 cells properly with the BMS board.

· Place the first parallel group of 5 NOS with the positive side up and then place the second parallel group with the negative side up. And the last third and last group will again have the positive side up.

You can use the cell holders or spacer to assemble the cells.

Step 8: Connect Nickel Strips:

Use spot welding to connect the Nickel strips with the cells. Cut them according to the pack and make sure that it covers all the terminals. Leave a 10mm strip extra to connect the BMS. For the arrangement we are making, you will need four long strips for parallel connection and 10 small strips for series connection.

Step 9: Add the BMS:

The battery management system is a very important component of a lithium-ion battery pack. It balances the cell voltage, avoids over-discharge, monitors the cells, and much more.

· Connect the first parallel group of the negative terminal bus to the B –(negative) and positive terminal bus to  B1.

· The third parallel group negative terminal bus will go to the B2 and the positive terminal bus will go with the B+.

Spot weld the nickel strip with BMS and solder it to the PCB pad.

Step 10: Get an Enclosure and Wire It:

As the battery strips and other components will be exposed and have risks too. it is better to have it enclosed in a proper box. The standard battery has two terminals. One goes with the load and the other goes with the charge. Make sure that you connect the right points.

Step 11: Final Assembly:

Install all the components in the enclosure and use hot glue to fix them. After securing the battery pack, make sure there aren’t any loose connection and close the lids of the box.

Your Lithium-ion battery pack is ready now. Don’t forget to keep a charger to keep using the battery pack.