Makita XGT 40v BL4040/BL4045/BL4030 AliExpress battery kit; parts and assembly

The original 21700 cells were used in this build. The original battery pack would no longer charge and would display a red light on the charger upon mounting. This was most likely due to a faulty BMS. The battery itself would flash two green lights of each side, alternating between them.

0:00 Intro
1:08 Genuine Makita BL4040 internal parts and components
4:00 AliExpress BL4040 Kit parts
4:28 Kit included Nickel strips
6:18 Battery holder case with 21700 cells
7:08 Spot Welded cells in case
8:22 Battery case with top BMS board
9:37 Assembling battery pack inside shell
11:34 Kit battery pack on Genuine Makita charger

Please be cautious when working with lithium batteries. These are not toys and can cause severe bodily harm, property damage and/or potentially loss of life.

Do your own research. This is just my immediate impression of these packs.

I can confirm the kit worked on a Makita product. It’s only a matter of a stress test for endurance.

Link to BL4040/BL4045/BL4030 Battery Kit (no cells):

https://a.aliexpress.com/_mriQ6JQ