40 LG MJ1 3500mah 10a 18650 Cell Modules
Get em before Elon Musk buys them all!
Here are 36v Ebike modules perfect for salvaging 40 LG MJ1 3500mah 10a cells which are one of the best cells on the market and you can get them for just $1.25/cell and a little bit of work. The cells are in 10s4p configuration. You can salvage them as a module or break down to cell level. We have disassembled hundreds of these modules and the cells have all tested near full capacity. We did not figure out the BMS, it is proprietary, and these modules are for salvaging the cells inside. Most of these modules were salvaged due to a defective BMS which is perfect for us, that means good testing cells and a BMS that we can't reuse anyway. Below is a step by step guide on how we disassemble these modules. Most cells were sitting around 2.8v which is great for storage and also a reason why these cells test like new. The modules are used but have not been cycled too many times based on our large spot test and also because many of the packs just had a faulty BMS.
Below is a step by step guide on how we disassemble these modules for cell recovery. The cells come out super clean even though the space between the holders and enclosure is filled with foam. The foam is easy to work with and much better than glue so don't be discouraged by the foam. The cells are clean and inside a completely enclosed shell. You'll need a T-15 security bit at least 1.5" long, any T-20 security bit, a flat head screw driver, and a plastic prying tool. All can be found at Harbor Freight, Amazon, Ebay, or likely already in your tool collection.
Step 1. Remove the 5 screws with a T15 security bit. The bit should be at least 1.5" long to reach the screws.
Step 2. Pry open from the handle first. You can go right through the handle to create a wedge to keep opening pressure on the plastic.
Step 3. With the wedge in place, carefully hammer another flat head screw driver down the seam on each side until you reach towards the bottom. Do not round the corner to the bottom.
Step 4. Pry open the plastic case from the handle side. Since this is just foam you do not need too much pressure. Just keep a steady opening pressure and you will hear the foam start to give away.
Step 5. On the handle side you will find 2 T20 screws that need to be removed which bolts the cell holder shell to the enclosure near the handle.
Step 6. Take a plastic scraper and run it down the sides all the way up and down to loosen up the foam. Stay close to the plastic case edge so you don't hit any balance wires. Clear away on the handle side too, not the bottom side. The idea is to loosen this foam up to remove as much friction as possible.
Step 7. From the handle side, pry the pack outward getting under between the cell holders and the case. Keep in mind these cells are also in a thick plastic enclosure so you can pry against the plastic underneath. Do not pry too hard, just keep a steady medium pressure and you will hear the foam start to break away.
Step 8. Now that the pack has been pulled out of the case the bottom will be held on by 3 wires. Cut those 3 wires one at a time. Now the module will be out of the enclosure.
Step 9. Peel back the green barley paper laid on top of the nickel and cut the bms wires one at a time. Trim the wires close to the edge so they can't touch anything. The barley paper comes off very clean. Do this on both sides. At this point, if you want to salvage the 10s4p module you can stop here. There will be clean nickel connections you can work with. To continue breaking down to cell level follow the next steps.
Step 10. On the BMS side you will find 4 screws where the main wires connect to the BMS with ring terminals. Wipe the foam away real fast and remove those 4 screws with your T-20 bit. Remember when you remove the wires you want to cut away as much of the wire as possible to prevent them touching each other and also only cut one wire at a time.
Step 11. Now that the 4 T-20 screws are removed you can use your plastic pry tool to get under the BMS and pry it up from the one side where you removed the screws.
Step 12. The other side of the BMS will be held on by the balance wire connector. Pull off the balance connector and now the BMS will be removed from the pack.
Step 13. You will find 4 T-15 screws bolting together the two sides of the cell holder shell. Use your T-15 security bit to remove those 4 bolts. You may need to clear the foam out of the holes with a flat head screw driver. Make sure your bit is set in the bolts nicely before loosening so you don't strip the bolts.
Step 14. With the shell bolts removed, now you can remove the nickel and spot welds. When working on removing the first side be sure to not let a nickel section touch another nickel section, it will spark and cause a short. When one side of the pack is done you can work faster on the other side without having to worry about a short. Do not do this work on a metal table.
Step 15. With the nickel and the 4 shell bolts removed you can now pry apart the two shells to get to your super clean 40 LG MJ1 cells! We find it easiest to hold the bottom of the shell in a clamp and hammer both sides back and forth to wiggle the plastic shell off. This can be done other ways as well and can take a little time to loosen the friction.
You are now done extracting these cells from the module. The first one or two will be a learning experience but you will get the hang of it and be able to disassemble each additional one faster and faster. For reference the cell specs are below. These are perhaps the greatest cells on the market and as you will see they come out super clean even though the plastic enclosure was filled with foam to keep the pack tight and for impact resistance. The cell holders can be reused.
These packs are for disassembling and cell recovery. The BMS should be recycled and removed from the pack since it is proprietary. These are guaranteed genuine cells from a major brand and they even have the warning label on the shrink wrap. Cylindrical lithium-ion battery cells should never be used in e-cigarettes for vaping or other consumer devices that allow for the cell to be removed. Certain issues like mishandling by the consumer and broken or faulty springs and circuits can cause inherent dangers. Cylindrical lithium-ion cells are intended to be assembled into enclosed battery packs with protective circuitry.
Each complete module weighs 6.5 lbs.