Unconventional Battery Mounting

[chilvence]

Hello everyone.

I have been browsing for a while with great interest, there are some amazing projects on show here.

I got introduced to electric bicycles by accident really, as my dad owned one but handed it down to me as he became more unfit to ride. If I hadn't been introduced this way I probably would not have ever bothered, as most of the bikes you can buy off the shelf are either too expensive for the fun you get out of them, or seem to have surprisingly ridiculous design decisions built into them. Mine was a giant bike with the battery between the seatpost and the wheel, and the chain encased in a stupid plastic enclosure which made it impossible to re-attach should it fall off (which it frequently did with my riding habits and due to it being a sloppy, slack, looooong chain with a dodgy tensioner). Horrible design, testament to the fact that just because a big company does it, doesn't make it clever.

My question is this; why do all ebikes have the battery in the oddest places, when the obvious solution is to use a standard frame and stick the battery inside the front triangle - where a normal motorbike has engine and other guts. No need to mutilate a hundred years worth of frame design, make extra work etc.. This was what I did with the parts from the giant bike, and it was a much nicer ride while the nimh battery lasted.

Theres even the far more convenient idea of building the battery into the wheel itself, which I think is much more elegant and if popularised would lead to a kit that you could just swap a wheel out, connect the throttle and away you go - ideal for the 99 % of the population that don't have time to get their hands dirty.

I realise it could just be me, but this seems to be a congenital defect almost, preventing ebikes from looking and performing in a way that can be taken seriously.

I've been reading up here on how to build custom battery packs, which is the way I think I will go if I decide to revive my ebike, but I haven't seen anybody take on a self build of the in-wheel battery idea..I'm just hoping I can wrap my head around charging balancing the cells safely, never been that good with electronics

 

[FMB42]

Welcome to ES chilvence,

There are several reasons for the unconventional battery mounting locations that you see these days. Below are just some to reasons and issues for this:

1. Many of the more common LifePo4 batteries are too large to fit in the average "slopped top tube" framed MTB and/or Hybrid bicycles on the market today.

2. Traditional "non slopped top tube" framed bicycles are becoming scarce. Another problem with many of these "traditional" frame style bikes is that they often offer no front suspension and/or are equipped with "out dated" braking systems that are hard pressed to meet the needs of a 20+mph 50-80lb bicycle.

3. Multiple lead acid battery configurations often require a custom made bracket, that many riders are unwilling or unable to fabricate, in order to mount them within the frame.

However, the drawbacks of mounting a 10-25+lb battery pack on a rear rack can result in some very real "issues" (with poor handling being the biggest problem imo). Having said this, I would suggest that you follow your concerns with "unconventional" battery mounting locations by considering a Ping or lipo battery build that will allow for an "in the frame triangle" placement.

 

[John in CR]

I realise it could just be me, but this seems to be a congenital defect almost, preventing ebikes from looking and performing in a way that can be taken seriously.

Can't be taken seriously??????????? Such a statement can only come from a pedalist who's choice in bikes is some kind of status symbol and who has never been exposed to high performance ebikes. It's pedal bikes that can't be taken seriously as a mode of transportation. Case in point is the Netherlands, probably the leader in bike use per-capita in the developed world, and last year the Dutch bought more ebikes than pedal bikes. I'd say that's pretty serious.

China put over 10 million electric 2 wheelers on the road each of the last 5 years, most of which were ebikes. I'd say that's pretty serious.

On a micro level take me as an example. I've had and loved driving a car for 35 years, but I hate traffic. I'm not out to save the planet or to save money. Those are just side benefits. I discovered the ebike almost 3 years ago, and I ride because it's more convenient and much quicker than going by car. The fact that it's fun and makes me feel like a kid are just other side benefits that make me look for an excuse to run errands or stretch a required ride into a longer pleasure ride. We have a family of 5 and I'm the only driver, and my lowly can't be taken seriously ebike has forever changed our family's transportation. Now the family minivan sees at least 95% less use, and sits parked for weeks literally at a time. I love cars, but the ebike is better for most of our transportation needs. I'd say that's pretty friggin serious.

I take it that you have a car, probably with a bike rack that your bike rides on typically greater distances than it's ridden, a common occurrence that really cracks me up. I guarantee I can handily beat your car across town, about 15 miles here, and at peak traffic times I can probably go there, do what I need to do, and get back home while you're still sitting in traffic on your way there. Plus, it's quite likely that my ebike would embarrass your pride and joy leaving a stop light. Don't you think that's serious?

I could be wrong and maybe you're a hard core cyclist and commute to work by bicycle. In that case, I do respect the performance of your human motor, as well as your commitment, however, I hope you really don't expect anyone other than those like yourself to take your vehicle choice seriously as a transportation device....puullleeezzzz!

Try to find some ES members local to you to hook up with for a spin on a real ebike, and give yourself a real eye opener.

John

PS- In the triangle is a great place for batteries if they fit. Also, some of us keep our bikes ugly intentionally to greatly reduce the risk of theft.

 

[spinningmagnets]

There have been several threads about which full-suspension frames have the largest triangle space. Most of the best options are older, as many FS frames place the shock somewhere inside the triangle. Also most posters want to make the battery placement easy for themselves, and building a triangle enclosure can be time-consuming and somewhat difficult for the average apartment-dweller (not everyone has a garage and serious tools available). Heres one example of an FS with a good triangle, older frame means not available new:

Nicks black eTownie showed a use of several ideas that others had mentioned in the past in various posts. Nick used methods that showed certain techniques were indeed successful in having a good result, while being fairly easy to implement.

The current situation is made worse by something I noticed recently. Many downhill (DH) and Dirt-Jumper (DJ) variations of the mountain bike genre do not have a male/female frame choice, but are going towards a uni-sex low top-tube style that results in a long low bike triangle (split by the seat-tube), instead of the classic dual triangle "diamond" shape.

Whether this observation is correct (or just my imagination) I can't help but to notice that, in common new bike frames that are very strong and accept aftermarket forks (desireable features in a 30-MPH E-bike), the available triangle space is shrinking. Look at oatnets Tidalforce frames for sale. Awesome frame, but a small triangle: http://endless-sphere.com/forums/viewtopic.php?f=31&t=18112#p263927

If you began selling battery triangle boxes, I believe you would be surprised at the immediate response, however...you would also be equally frustrated at trying to build a box to fit a customer-supplied tracing of his triangle. The size and shape of commonly encountered triangle-spaces is widely varied and all too often just an inch too small to fit the desired voltage/Ah...if 36V and 8-Ah, no problem, but 15-Ah of 48V? it gets very sticky, very fast.

The Electra Townie (and Trek Pure / Giant Suede) have large triangles, but also have hardtails. The "serious Ebiker" market is not big enough yet, to fully support a full-time business making E-bike sprecific frames.

 

[neptronix]

Chivalence, welcome.

There is no congenital defect of bicycles that doesn't allow for mounting the battery somewhere near the middle of the bike.

For every 2 eBikes with a poorly designed rear rack and heavy battery that knocks around, there is one fairly well designed rig, like so:

^--- my girlfriend's eBike.

And there are plenty of bicycles still being made today that have triangles that will work well for a mid-mount:

^--- 2009 trek 4300

Just as well, if you spend any amount of time on this forum, you will find many many creative solutions for battery mounting.

If you DIY, and especially if you use lipo or custom configurations of cells, the sky is the limit for battery mounting.

A lot of us here decided to go the DIY route because pre-built bikes are overpriced and do not perform to our liking.

So anyway, welcome to the forums.. go read around and see what people have done. Maybe it will provide some inspiration

 

[chilvence]

Thank you all for the responses, I was mostly in fact posting to gauge other peoples opinions

In response to John, I do not have a car, nor a licence, and I would probably be hard pushed to drive anything other than an automatic - and even then I would resent parking and traffic . I am in fact a 27 year old automobile virgin, as it were, but I suppose travel distances are a lot less where I live than where you do, so it makes a lot more sense for me. And for what its worth, its not my commitment to cycling, and there is no spandex in my wardrobe - I simply know my way is better

Where I am really coming from is that unless people start coming out with ebike designs that are strongly visually desirable, no interest will be generated to increase the market. I forsee a future where 90% of transport needs would be filled by 2 wheeled vehicles of some variety or another, purely because of energy efficiency, but the more stubborn die hard drivers need something that will make them open their eyes a bit. There aren't many ebike ferraris or lamborghinis is what I am getting at, and while I realise 1 in a thousand people would have the money to spend on a ferrari, I doubt there are many drivers out there that dont fantacise about having a ridiculously expensive sports car. When you think of the word car, you dont immediately think of the word 'ugly', whereas with e-bikes... there is room for improvement - and as other people have pointed out, alot of the better designs are purely limited to what hobbyists taking their own initiative have come up with. In fact, when it comes to the point where I think I have better ideas than the manufacturers, you have to worry a bit

 

[oldpiper]

There aren't many ebike ferraris or lamborghinis is what I am getting at, and while I realise 1 in a thousand people would have the money to spend on a ferrari, I doubt there are many drivers out there that dont fantacise about having a ridiculously expensive sports car. When you think of the word car, you dont immediately think of the word 'ugly', whereas with e-bikes... there is room for improvement - and as other people have pointed out, alot of the better designs are purely limited to what hobbyists taking their own initiative have come up with. In fact, when it comes to the point where I think I have better ideas than the manufacturers, you have to worry a bit

Oh, there are some ebike Ferraris and Lamborghinis out there, probably many more than the proportion of regular F or L's to the total market, the total market for ebikes is just small to begin with. For examples that come to mind, there's Stealth, M55, or (more like an older Mercedes - solid, comfortable, but not a rocket) Optibike and several others.

However, your statement about hobbyists making better ebikes than the commercial ones, you'll find that to be true in almost everything you think about, not just ebikes. You think the pro golfers or tennis players play with "stock" clubs or rackets, without extensive "tuning" (sometimes as far as to be unrecognizable by an average player)? Think again. And it's not just sports - I am a chemist, work with high-tech instruments (and this ebike thing is all science anyway, isn't it?) - no one who wants to do anything out of the ordinary uses a $300K mass spectrometer (for example) as it comes from the factory - they either take an old one and modify it so it's unrecognizable or they build one from scratch themselves. Same for physicists, and even biologists take their organisms and genetically modify them to "improve" them for their purposes. If you want really good-looking, get a commercial bike or spend mucho man-hours to make one yourself. But if you want really good-looking and really good-performing, get a commercial bike and improve it yourself. The people who frequent these forums are that kind of people, not usually the ones who can afford an M55 (until the lottery finally realizes that I have the winning ticket).

One other thing about ebikes, in many places there are very restrictive laws about power and speed for ebikes. This just means on the road, off-road you can do pretty much what you want if you stay away from pedestrians, etc. Many ebike manufacturers (including those who specialize in conversion kits) sell only ebikes or kits which would not exceed the lawful limits, I guess because we live in such a litigious society and "deep pockets liability" is always at the back of their minds. So if you want to push the limits, you're often on your own.

JIMHO,

Cameron

 

[MadRhino]

Modern good FS bikes have no triangle space, but they are more suitable than ever to build a performance E-bike, because of their frame stiffness, very good suspension and brake components. I don't miss the triangle space, for keeping the natural balance of the bike requires front battery mount when you build with a rear hub motor.

I would not want embarassing my knees anyway, cause I like peddling the bike and want freedom of posture to manoeuver in the mountain. Our E-bike does not need to be conventional, it just need to handle nicely in the situations where we ride them.

 

[chvidgov.bc.ca]

One word. Recumbent....awesome mid-bike low down battery placement. Awesome bikes.

http://www.amazon.com/Sun-Ez-1Sc-Pannier-Alloy-Black/dp/B000AO9MAK

Sure feels good to have 2000 watt hours of lithium right under your ass...