Replacement Battery

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Add a bigger battery to increase range and ride time.


These batteries, also known as Reention Dorado batteries, fit into the downtube frame of your Biktrix eBike. Made with top-of-the-line Samsung and Panasonic cells, it doesn't get much better than this.

  • Juggernaut Classic
  • Juggernaut Ultra 1000 & 1000 Pro
  • Juggernaut Ultra FS
  • Stunner LT
  • Stunner X
  • Stunner Step-Thru
  • Stunner Step-Over
  • Swift Step-Over
  • Swift Step-Thru
  • Skycap


These replacement batteries are enclosed within the frame of:

  • Juggernaut Ultra Beast (48V 15Ah)
  • Challenger (48V 14Ah)
  • Juggernaut Ultra FS Pro
  • Juggernaut Duos (52V 17Ah)
  • Swift Lite (36V 10Ah)

Range Extender

These Range Extender replacement batteries are compatible with the following eBikes:

  • Juggernaut Ultra Eagle (52V 21Ah only fits the large frame Eagle)
  • Juggernaut Duos** (additional battery)


**The following are NOT compatible with the 21Ah downtube batteries (if you are unsure of the fit, please email us):

  • 18.5" Ultra Duo 2 Step-Over
  • Classic Duo Step-Over
  • Ultra Duo 3 Step-Over

Charger included in each battery purchase.