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DeWalt 20V MAX 5Ah Battery Rebuild | Step-by-Step Tutorial

RenewSparkBatteries

10,261 views

Rebuilding a DeWalt 20V MAX 5Ah lithium-ion battery pack with brand new cells.

In this video, I take you through the full rebuild process — from opening the case, removing old cells, spot welding new ones, and reassembling the pack.

⚡ What you’ll see in this video:
• Safe teardown of the OEM battery case
• Preparing and installing new 18650 cells
• Spot welding nickel strips
• Final test of the rebuilt battery

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🔋 Compatible Cells (available from RenewSpark)

I used different cells in this build. These are compatible 18650 options you can use for the same rebuild — either one gives you the full 5.0Ah at 2P:

BAK N18650COP – 2500mAh, high-drain:
https://renewspark.com/products/bak-n...

Samsung 25R – 2500mAh:
https://renewspark.com/products/samsu...

See all 18650 cells:
https://renewspark.com/collections/18...

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🔧 Parts & Materials

Pre-cut nickel strips (DeWalt 20V MAX 5Ah):
https://renewspark.com/products/nicke...

Pure nickel strips (0.2 × 10mm):
https://renewspark.com/products/pure-...

Fish-paper insulator rings:
https://renewspark.com/products/18650...

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⚡ Tools Used

Spot welder: https://amzn.to/4neVzzh
Battery tester: https://amzn.to/4mVhw6c
Soldering station: https://amzn.to/4ghKhIA
Solder wire: https://amzn.to/3HL5jm3
Desoldering tool: https://amzn.to/46oi3s1
Desoldering wick: https://amzn.to/4gceNn3
Cut-resistant gloves: https://amzn.to/4nVFSgL

⸺

Tools I Use (Free App):
🔧 Build safer, cleaner battery packs with the RenewSpark Tools app — IR checker, pack designer, wire & nickel sizing, load calculator, and more.
📱 Download on the App Store:
https://apps.apple.com/us/app/renewsp...

If you’re interested in seeing any other rebuilds, let me know in the comments so I can make a video for it

🔋 Disclaimer: Lithium-ion battery rebuilding can be dangerous if done incorrectly. This video is for educational purposes only. Attempt at your own risk and always follow proper safety precautions.

👉 Subscribe for more rebuilds: @renewsparkbatteries

11 Comments

@RenewSparkBatteries Creator 1 year ago Pinned

Thanks for watching! 🔋⚡
Want more rebuilds like this? 👉 Subscribe here: https://www.youtube.com/@RenewSparkBatteries?sub_confirmation=1
Drop a comment with the next pack you’d like me to rebuild (Makita, Milwaukee, Snap-on, etc.) and I’ll make it happen!

@Plain625-p7m 9 months ago

Thanks for this rebuild! I have all 5AH packs. If you bend the ears up on the old straps you can grip them with regular pliers and roll the strap up and tear it off real easy. Thanks Again.

@wallyklw5 3 months ago

Thx. Gonna give it a go

@hr.4576 1 year ago (edited)

Hi! Thanks for your video it will be helpful 😉
Maybe a material list in the description would bring more subscribers 👍

@lovemyozzy 5 months ago (edited)

Yup I almost lit the batteries on fire twice and I guess I don’t need this pack anymore

@ericwhitney6067 5 months ago

If its a vent why doesnt it vent automatically and reset . Seems like thats not what it actually is seems like its an overheat thing that only pops out and made to not reset . Basically killing the cell

@hr.4576 10 months ago

Hi keep going with these videos man👍
I watch it again and I noticed you used molicel 18650-p30b-2.85Ah? How that's improve de final performance and ah of the battery?

@jamesjames5715 8 months ago

good job
after rebuild how much is the new capacity?

@AndyWoodward-pk3gz 6 months ago

So 10 replacement cells are gonna cost you $49.90 (not to mention all the other parts), but a new DeWalt 5Ah battery is about $48.00. What am I missing here?