Build Your Own Battery Pack from Recycled Esco Bars

Introduction to Esco Bars

Esco bars, also known as e-bike battery packs, are becoming an increasingly popular choice for building custom battery packs. Esco bars are battery packs that have been salvaged from wrecked or damaged electric scooters (escooters). They provide an affordable source of lithium-ion battery cells that can be repurposed for a variety of applications.

What are Esco Bars?

An esco bar is simply the battery pack from an electric kick scooter (e-scooter). Many e-scooter companies use standardized battery packs that are easy to remove and repurpose. These packs contain 18650 lithium-ion battery cells, which are also commonly used in laptop batteries, power tools, and even Tesla vehicles.

By salvaging the battery packs from damaged or decommissioned e-scooters, it provides an economical way to obtain a large number of lithium-ion cells. The battery management system (BMS) inside the esco bars also provides essential protection to the battery pack when repurposing them for other uses.

Benefits of Using Esco Bars

Here are some of the main benefits of building a custom battery pack from esco bars:

• Cost savings - Individual 18650 cells can be expensive, using recycled esco bars provides a significant cost saving.
• Convenient - The cells are already spot welded together in a pack with a BMS.
• Eco-friendly - Recycling and repurposing e-waste gives the cells a second life.
• High capacity - Each esco bar contains multiple 18650 cells, providing plenty of capacity.
• Flexibility - The battery pack can be configured to provide different voltages and capacity.

How to Build a Battery Pack from Esco Bars

Building your own custom battery pack from recycled esco bars is a relatively straightforward project if done carefully. Here are the key steps involved:

1. Source the Esco Bars

First you need to source some esco bars. Look for recyclers or e-scooter repair shops that might have damaged or written off e-scooter battery packs. You can often find packs being sold used on sites like eBay or Alibaba.

Inspect the condition and try to test the individual cells if possible. Only use undamaged esco bars in good condition.

2. Dismantle the Esco Bar Housing

Carefully dismantle the plastic and metal housing of the esco bar to expose the 18650 battery cells inside. This housing is not reused. The cells will be spot welded together in the required configuration.

3. Test and Sort the 18650 Cells

Test each 18650 cell individually to check its voltage and capacity. This allows you to sort and select only the best performing cells for your battery build. You may need to ‘balance’ the cells at this stage to bring them all to the same starting voltage.

4. Configure the Cell Layout

Decide the number of cells you want wired in series and parallel to achieve your desired battery voltage and capacity. Lay out the 18650 cells physically in the required series and parallel configuration.

5. Spot Weld the Cells

Use a spot welder to weld nickel strips between the terminals to interconnect the 18650 cells in the determined series/parallel layout.

Take care to get firm welds between all cell terminals. This provides the electrical connections between the cells.

6. Add a BMS

A battery management system (BMS) is essential when building any lithium-ion battery pack to provide protection and cell balancing. Salvage the BMS from the esco bars or use a new BMS module suited to your pack design.

7. Enclose in a Housing

The interconnected battery cells now need to be enclosed securely in a protective housing. This helps protect the cells and also electrically insulates them. 3D printed housings work well for small DIY packs.

8. Configure Discharge/Charge Cables

Finally, solder discharge cables to the battery negative and positive terminals. Add an XT60 plug or similar to create an easy connector for charging and discharging the battery.

Take safety precautions working with lithium battery packs throughout the process.

Example Applications

Some example uses for a DIY battery pack built from recycled esco bars include:

Electric Bicycle Battery

Building a custom lithium battery pack to power an ebike conversion kit. The high capacity esco bars can create a pack providing up to 72V and 10-20Ah.

Solar Generator

Create a solar generator by combining a battery pack made from esco bars with a solar panel and power inverter. Provides renewable power during blackouts.

EV Conversion

Use esco bar packs to build a full EV battery for a car conversion. This requires combining many packs in parallel and series to achieve 100+V and up to 200Ah or more.

Power Tool Battery

Reconfigure a 10S esco bar pack into a 18V or 24V lithium battery to custom fit and power tools originally designed for lead acid batteries.

The flexibility of esco bar battery packs makes them useful for all kinds of applications where a custom lithium pack is required.

Safety Tips

Here are some important safety tips to follow when repurposing esco bars:

• Use protective equipment - work gloves, eyewear, enclosed shoes.
• No short circuits - Avoid shorting battery terminals together.
• Watch cell polarity - Take care to wire cells correctly in series.
• Quality welds - Incomplete welds can cause overheating and fires.
• Add fuse - Fit a suitably rated fuse to protect from over-current.
• No over discharge - Set low voltage cutoff in BMS to prevent deep discharge.
• Better ventilation - Lithium cells can overheat, allow good airflow.
• No disassembly - Do not dismantle or damage lithium cells.

Carefully following precautions and best practices will ensure your custom esco bar battery build is safe and reliable.

Conclusion

Repurposing recycled esco bar battery packs provides an economical way to build custom lithium battery packs. With a bit of electrical knowledge and the right tools, you can configure esco bar cells into a pack to power almost any application.

Just remember to take the proper safety precautions when handling lithium battery cells. Done properly, esco bars present almost limitless possibilities for carbon-friendly energy storage and powersports applications.

FAQs

Where can I find used esco bars to recycle?

Look for recycling centers or e-scooter repair shops. Also check online marketplaces like eBay or Alibaba for people selling written off esco bar packs.

What voltage and capacity can I expect from esco bars?

A typical esco bar contains around 10 18650 cells wired in series, giving about 36V. Capacity varies but is often 5-10Ah. By wiring in parallel you can increase capacity.

Is a spot welder required for rebuilding esco bars?

Yes, a spot welder is recommended to get good connections between the 18650 battery cells when reconfiguring them.

Can I just connect esco bars together to increase voltage?

No, the bars cannot just be daisy chained. The 18650 cells inside need to be rewired into the required series and parallel configuration.

Do I need a BMS when repurposing esco bars?

Definitely, a BMS is essential to provide cell balancing and safety cutoffs when charging and discharging. Reuse existing BMS or add an external one.