This sleek external battery is a secondary battery on the Juggernaut Duo series bikes along with the Juggernaut FS Pro 2. Use this battery if you want to ride even further than you can with just the internal hidden battery! A high-quality design and many power options provide reliable power and range to extend your ride!

Note: This battery has 3 different case heights - the larger 17Ah and 21Ah models may not fit smaller Step-Over frame sizes. Consult the pictures here for battery height and notes below for frame size compatibility.


  • Juggernaut Hub Duo
  • Juggernaut Classic Duo
    • 2022 Model Year Step-Over bikes only compatible with 52V13Ah & 52V14Ah Batteries
  • Juggernaut HD Duo
  • Juggernaut Ultra Duo 1, 2 and 3
    • 52V19Ah & 52V21Ah Batteries Incompatible with 17" Step-Over Frames
  • Juggernaut Ultra FS Pro 2
    • All frames compatible with 52V13Ah & 52V14Ah Range Extender
    • Only XL 20" Frame compatible with 52V16Ah & 52V17Ah Range Extender
  • Juggernaut Ultra Eagle
    • 52V19Ah & 52V21Ah Batteries only compatible with Large Size Frame


Note: If you have a Juggernaut Duo Series bike you will need a Range Extender plate to connect your battery to the bike - consult this guide if you need help determining which type is on your bike!

Wondering about the brand options and what to pick between Top Brand and OEM/Sinowatt? Take a look at this FAQ for some information!

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Customer Reviews

Based on 5 reviews
Robert DenHerder


Ralph Rader
Extender Battery

Mounted easily. works as advertised. Wish there was a better way to rout the connecter cable. Have it covered with Gorrila tape so I don't trip over it when I get on the bike.

Dennis Shamburg
Great to have plenty of power when off the grid for week or more at a time.

This is a handy way to have the extra power for bike use when camping off grid for extended periods. Unless you have an elaborate solar power setup, it takes quite of bit of time to totally charge up the larger batteries. It adds extra weight to the bike, but that's not a big issue for my particular use. It would be a smart idea to drill and tap a couple of holes in the frame to be able to clamp the electrical cable down, so it's not able to be snagged by brush or your foot. I ended up buying the cheaper extra battery because in haste , I didn't review the options close enough. Its not even worth trying to exchange it because of the return policies. I think that selection process could be a little more easier to understand if it were more obvious that there are two options of battery quality. I'm happy with the outcome, and know I have plenty of battery power to get me around before I have to charge everything back up. I use mine for better fishing access and exploration when camping, i don't use the extra battery a lot for just doing errands and exercise trips, the main one ( 17 AH ) does fine for that.

Dennis Tsai
52v, 13AH extender battery

The battery was sent expeditiously, well packaged and complete as described, and included a charger which can be used on my Juggernault Ultra Duo also. However, my range increased only about 11 miles which is not much ( I had expected ~20 miles more). So possibly not cost effective for $400 more... you can decide if it's worth the additional $$s for you.

Marvin Schlabach

Works Great!