Faraday auxiliary battery update!

People love to ride our bikes and many of them want to ride even further between charges. That’s a good thing! And if you’ve followed us, you know that we’ve been working on an auxiliary battery to address that need. Here’s an update and a teaser for the design of this much awaited accessory.

The plan has always been to double the range of a Faraday to 40-50 miles via a removable battery that sleekly fits underneath the seat of our bikes. To achieve this we needed to build something from scratch since no existing battery on the market was light enough or compact enough to suit our needs. It needed to look good too. We’re picky. While we can’t share the final photos just yet we think you’ll love how it’s going to look and the options we’re planning so you can add your own flare too!

This battery we’re building is extremely dense. In energy terms, that’s a great thing! All-in with the case, cabling, and end caps, the battery weighs just 4.5 lbs, which doesn’t impact the smoothness of the ride or the balance of the bike that you know and love. The capacity of the auxiliary battery exactly matches our internal battery – that’s an additional 306 Wh but in a much more compact space. Here’s an image that helps illustrate the density of the final product.


Faraday, we’re excited to say, might have the most energy dense battery system on the market across all transportation categories. For comparison, a Tesla battery provides about 117 Wh/kg, while the Faraday auxiliary delivers 153 Wh/kg, and our internal battery is a whopping 211 Wh/kg since it doesn’t require all the cabling and packaging of the auxiliary. Once you combine that energy density with the efficiency of a bicycle, it’s a no brainer, bikes beat cars again!

But does it work, yet? Yes!

Check out this ride below that Thomas completed on Sunday in Oakland using the new battery.

To recreate a “real life” use case, this ride was completed with a 2-year-old Porteur S daily commuter on a single charge of both the internal and auxiliary battery. In theory, that’s 612 Wh minus the loss of battery capacity from the age of Thomas’ internal battery. With his setup, our standard assist level delivered nearly 38 miles of range with 1,900 ft of climbing through the Oakland hills. In short, it works! On newer bikes and flatter terrain, it’s realistic we’d hit 45 or even 50+ miles on a single charge. Excited yet?

So I know the question you’re all asking is, When can I get my hands on it!?

The answer is that we’re still not ready for a July release as we anticipated at the start of the year. In fact, we’ve decided to push the delivery date all the way back to January 2019.

But if it’s ready and working, why can’t we just ship it now? While we’ve made enormous progress and are close to being able to hit full-scale production, we’re still obsessively checking every single possible safety and certification box. We’re also initiating a rigorous testing schedule to ensure that down the road you avoid any unnecessary service issues. Frankly, we didn’t allocate enough time for this process in our original estimates. This new delivery date corrects for that and adds some buffer time so that we can be sure they’ll be in your hands by the beginning of the year.

For those of you who have been waiting, thank you for your patience. We’re getting close!