http://www.fluxmopeds.com/innovators
People are ALWAYS asking me about good deals on electric vehicles or ways to use DIY to get a great price on a build-your-own setup.
That’s one reason why I was excited to get a call from Matt at Flux Mopeds. Flux has been doing some great work designing, manufacturing and selling electric scooters. In their innovative design, the vehicle uses a removable lithium battery pack. This solves a host of potential problems from “where do I plug in?” to “what about cold weather?”.
By taking out the battery, you can literally charge it ANYWHERE! At you desk at work, in your dorm room, in your kitchen – anywhere you have an electric outlet. Likewise, charging the battery indoors, separate from the vehicle, means you even have a warm battery pack in the winter. In many places, you can even park mopeds on the sidewalk or at a bike-rack.
When Flux told me they wanted to clear out their earlier models, still brand-new, but WITHOUT battery packs, it got my mind churning – what would it take to just build a battery pack for one!?
They agreed to loan me a cycle, so that I could design my own pack for it. Now I already happened to have some NiMH cells around. I originally purchased these as a used Ford Escape Hybrid battery pack. They are also very similar to what’s in the original Honda Insight.
The EM-1 scooter has a 60V nominal system, so I figured it would probably run on a range of something like 70 volts on the high end to 50 some volts on the low end. The NiMH cells are 1.2V each, with 5 already assembled as a stick. Essentially, each stick is 6 volts.
All I really needed to do was put 10 sticks of cells together. I still had some of the black plastic trays that were originally part of the Ford battery package. I cut the trays to have two which held five sticks each, and connected them together with the matching bus bars, positive to negative, positive to negative.
To connect the two trays together, Used a flexible braid, one of the original battery cables from when I pulled the NiMH cells from my Vectrix to upgrade to the LEAF cells.
After that, I stacked the two trays together, then wrapped them with tape. It was a solid block of batteries.
Lastly, I added an Anderson Disconnect to the pack. This is a standard industrial part. One of the really nice things about the Flux Moped is that it is NOT using proprietary connectors. Instead, it’s typical parts, easy for a D.I.Y.er to work with.
As always, a person needs to exercise caution while working on battery electrical systems. Short circuiting a battery can lead to some pretty exciting sparks. Even 60 volts is technically high-voltage (one reason why golf carts are usually 36 or 48 volts…) Wear safety glasses, use insulated tools, and exercise common sense.
Under the seat of the scooter, a metal box is in place, designed for the original removable battery. I noticed that it was only held in my one large machine screw, which was easily removed. Without that box in the way, there’s even MORE useful space under the seat. Potentially, some more of the plastic could be removed. It looks close, but I’m pretty sure that 60V of Nissan LEAF cells would fit in this scooter.
Another advantage of the removable battery pack is that the scooter doesn’t have a battery charger built in. Chargers are typically designed for a very specific chemistry and voltage. Since we are designing our own battery anyway, we can use any chemistry and a bit of a range of voltages. To charge, Just unplug the battery from the scooter, and plug in whatever charger is appropriate for the battery pack. This is the EXACT same system that electric forklifts use to charge. It’s simple, and has been an a common industrial practice for years.
After I had the battery pack together, I set it down in to the scooter, then physically secured it using some spacers I built. Next, all I had to do was plug in the Anderson, flip the circuit breaker and turn the key.
The first time I did this, the cycle came right on, no unusual issues at all.
After that, it was time for a test ride.
The scooter rides great. It’s quick and smooth, without the noise and vibration of a gas engine. While it’s not as fast as my Vectrix, it’s a heck of a lot smaller, lighter, and easier to handle. That, and no motorcycle license required.
I mostly used the Ford Escape cells for this project because that’s what I had. This single string of NiMH cells is really only enough for just zipping around my neighborhood. If I wanted to use a scooter like this to it’s fullest potential, I’d likely build a pack from some brand new lithium cells, probably somewhere around 1.5 – 2kWh capacity. My buddy Dustin at Odyssy Trikes has been using LiMn 26650’s for his battery packs, and I’ve been impressed with the results. Those are the same chemistry as the Nissan Leaf Cells.
So, what makes sense economically for an EV?
Well, right now, you can buy a closeout scooter from Flux Mopeds for $950. That’s a BRAND-NEW scooter, but no battery pack. Their original scooter sold for $2,000, and the newer model goes for $2,400. If you can build your own battery pack for anything less than $1,000, you are getting a great deal. I just built one with parts I already had. Of course, most people don’t have those things just kicking around, but there are plenty of places that a person can purchase cells from, and it’s pretty straight-forward to build a pack by bolting cells together with bus bars.
Nowadays, lithium cells can be had from Chinese resellers for as low as $150 per kWh. Basic battery chargers can be very affordable as well. Potentially, you could have your own battery and charger for only a couple hundred bucks.
Add in the fact that you have NO maintenance on an EV other than adding air to the tires, and getting a deal like this is a “no-brainer”.
If you are interested in one of the closeout Flux Mopeds EM1’s, take a look at their web page at: http://www.fluxmopeds.com/do-it-yourselfer-special
You can also see a review I wrote previously at: http://300mpg.org/2014/08/18/electric-scooter-review-2014-flux-mopeds-em1-electric-scooter/
Till next time, stay charged up!
-Ben
{ 1 trackback }
{ 8 comments… read them below or add one }
Hey Ben,
I am about ready to grab a DIY model. Any updated thoughts on the batteries/configuration? I’m fairly new to this technology but am excited about getting into it. Ready to dive into your videos above as well.
Thanks for any advice you have.
Tim
Hi Ben. A friend and I have both picked up Flux DIY specials. He is planning a build based on 18650s from laptop batteries, and I am planning to source Leaf cells on eBay. I don’t have the cells yet, and since the Flux is at a friend’s warehouse right now, I don’t have access to it either. I am curious if you ever attempted to test fit Leaf cells into the Flux battery compartment?
Hi Matt,
The Leaf Cell Modules are about 9 inches by 12″ by just over an inch and a quarter thick. I measured a stack of 8 of them being 10.5 inches. So a block of 8 modules is 10.5 x 9 x 12.
There’s quite a lot of space under the seat of the Flux Mopeds electric scooter. The limiting factors are the back of the compartment where the rear wheel is and in the front of the compartment it’s a bit narrower, due to a frame member on either side coming down to where the double kick-stand connects to the frame. As the scooter is stock, there is plastic body inside the frame, which could easily be trimmed away. At the very bottom is sort of a steel tray that would have supported the original battery box. That is divided up into a wider rear section and a narrower front section. The back part is plenty wide for the Leaf batteries, but the front part isn’t. It looks like the space between the frame members IS wide enough for the batteries. So, what it may come down to is that a 60V Leaf pack should fit in there just fine, but you will need to trim some of the unneeded plastic under the seat and take a tin snips to the short sides of the front part of the tray. You would stand the cells on end, so that they would be 12″ tall (with the terminals on top, where you can get at them,) the cells would be 9 inches wide, going across the width of the scooter, and the stack of cells would be 10.5 inches, running the length of the scooter.
I think they should all fit in there just fine, but you will need to do a little modifications. Nothing major, you aren’t chopping the frame or anything, and it will look totally stock when you are done.
Here’s my one sample Nissan Leaf module inside a Flux scooter. The cell isn’t facing the right direction for how you will want your final project to be. It’s just in there like that because the plastic is slightly too narrow for the battery to be turned 90 degrees. It would just need a little trimming to do that.
(Please note that it’s a wide-angle shot. You can clearly see the vanishing point effect on the battery module. The top of the battery compartment isn’t as large and open as it looks, nor is the bottom as tiny and far away. Sorry, it’s what I had available for a camera at the time!)
Hi Tim,
I did get a chance to look at the specs on the Leaf modules and measure the inside of the battery compartment on the Flux. If I were doing it, I’d be very tempted to use 8 Nissan Leaf cell modules. 8 of them should keep you nicely in the range of the high and low voltage cut-offs of the scooter’s controller. 8 modules should fit inside just fine if you trim aways some of the plastic inside the battery compartment.
I already used Leaf modules in my Vectrix, and can’t say enough good things about them. Of course, I’m biased. I haven’t built any projects yet with 18650’s. I know a lot of people are big fans of those, and they would give you more flexibility in terms of configuration, but those always looked like a lot of soldering/welding to me!
Hi Ben!
Thanks for the video! Got me super interested in trying to take on this endeavour myself, but I’m super new in the battery diy area. You mentioned that it would be super easy to build a pack using bus bars. I was wondering if you had any reference material and/or videos on that topic as I would like to avoid as much soldering and welding as possible. You also mentioned you would do it with the LiMn 26650′s if you didn’t have the NIMH cells lying around, but I looked those cells up and they seem like the soldering/ welding type. So I guess I just wanna know what direction I should go in. Thanks in advance for any advice!
Bus bars are simply flat conductive bars (usually copper) with a hole drilled in either end for the cell terminal screw. Not only are they very easy to use, but because they are solid, you get a great electrical connection. (On cables with crimped or even soldered end terminals, you have multiple points at which you can have a less than perfect connection.)
For good general information on connecting cells, please take a look at one of the many web forums out there. Forums such as https://endless-sphere.com/forums/ have plenty of people doing some great projects and showing how they do them.
Best of luck!
-Ben
I LIKE IT, PRICE PLEASE ?
The scooter itself is one of the first-generation models from Flux Mopeds.You can contact them through their web page. http://www.fluxmopeds.com I don’t know if they have any left or not, but they were selling those as a “Do It Yourserlfer special” for $950. You would have to build your own battery pack. Exact cost on that depends on what and how many cells you use, and your cost per cell.