Skip to main content

Build Battery Packs

Cells

  • DIY500AMP.COM
  • Order #1584 Estimated Thursday, Sep 25
  • Ampace JP40 "LT Wrap" 21700 4000mah 70A Battery - Tabless Cell × 120
  • Subtotal $474.00 \text{ Shipping} $22.99 Total $496.99 USD

Welder

  • Heltec HT-SW02H
  • Order #114-4340207-9060214 October 30, 2025
  • Spot Welder & Milliohm Meter
  • 42 KW 7000A Capacitor Energy Storage Pulse Welding Machine
  • Subtotal $729.90 Tax: $43.79 Total: $773.69

Battery Case

Cost

  • Me: $497+$774+$390=$1660
  • Milwaukee (with worse cells): $279*8=$2232

Assembly

  • video
  • cell orientation 20260903_10h57m14s_grim.png
  • bottom contacts 20260903_10h58m24s_grim.png
  • top contacts 20260903_10h59m38s_grim.png
  • side board 20260903_11h00m21s_grim.png
  • soldering 4 contacts to the board 20260903_11h00m55s_grim.png
  • obliterating this bit contact for some reason 20260903_11h02m14s_grim.png
  • case with pastic bits and springs 20260903_11h04m02s_grim.png
  • second plastic thing goes into the springs, then 4 tiny screws 20260903_11h04m30s_grim.png