Range Extender Kit for Duo Series

Sale price $499.00 Regular price$699.00
Save $200
Sale price $499.00 Regular price$699.00
Shipping: Leaves within 6-7 business days


This sleek external battery is a secondary battery on the Juggernaut Duo series bikes along with the Juggernaut FS Pro 2/3. 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.

Compatibility Notes:

(1) 52V16Ah / 52V17Ah Batteries incompatible with 17" Medium Frame
(2) 52V19Ah / 52V21Ah Batteries incompatible with 17" Medium Frame
(3) 52V16Ah / 52V17Ah Batteries only compatible with 20" XL Frame
(4) 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! When buying your battery on this page the plate will be included!

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


    Bike Name 52V13Ah / 52V14Ah 52V16Ah / 52V17Ah 52V19Ah / 52V21Ah
    Juggernaut Hub Duo SO / ST
    Juggernaut Classic Duo Step-Over (1)
    Juggernaut HD Duo
    Juggernaut Classic Duo Step-Thru
    Juggernaut Ultra Duo 2 Step-Over (2)
    Juggernaut Ultra Duo 3 Step-Over (3)
    Juggernaut Ultra Duo 3 Step-Thru
    Juggernaut Ultra Duo 4 Step-Thru
    Juggernaut Ultra FS Pro 2 (4)
    Juggernaut Ultra FS Pro 3
    Juggernaut FS Step Thru
    Juggernaut Ultra Eagle (4)

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    Customer Reviews

    Based on 13 reviews
    Jim Shaw
    New Battery

    I ordered a new extended range battery from Biktrix as I’m planning for a few extended day trips this summer. Curtis quickly got my order in and I was surprised and pleased that it was on sale for $200 off the regular price. It was shipped and got here quickly with no issues. Thanks Curtis and Biktrix!

    Wayne Mulder


    Lucien Cortez

    WoW it’s great no more range anxiety

    George Parkson
    Nice addition

    The main battery gets good mileage, however I would suggest going with the extender. It fits nicely and can still use the step thru.

    Adam Gagnon

    Excellent customer service. Thanks

    Robert DenHerder


    Laurie Taylor
    Battery extender

    Received my item an waiting till spring to try out

    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.