An idea for placement of a 12Kg battery on E-bike

Hi,
Going touring requires a lot of energy, which is in my case a pack that weights 12Kg. (24S 20Ah A123 prismatic cells - 79.2V)
Initially I aimed for triangle installation, but this makes the pack non-removeable and can be a problem if you ever have a fault (or a very narrow stairway in some hostels) and need to lift the bike. Also a third of the battery would anyway have to be elsewhere as the triangle can only fit 16 of those cells.
Since those cells are modular, and since I carry 4 panniers - 2 front and 2 rear, I thought to split the pack into 6S segments.
Each segment will weight 3Kg, and be placed inside the inner pouch of it's panniers.
The panniers are Ortlieb classic panniers which are not only very strong, but are waterproof too. When mounted on my road bike at 100PSI, with all the shakes of the bike, they stay still and firm!
The inner pouch of each pannier is on the rack side, where it not only mechanically stronger in that part, but can support the most weight since it causes the least downward leverage.
There would be one cable going to the rear, splitting into the two rear panniers (and terminating with Andersons), and same for the front rack.
In that way I can achieve complete water tightness (The Anderson connectors would terminate inside the pouch), and the whole thing would be completely modular.
I would be able to lift the bike easily if I remove all 4 bags. (for example if I want to hop on a bus with only under-carriage as room for bicycles and other luggage)
This will also allow me to charge each 6S members individually once in a while, like a manual "6S-BMS".

I will also have Ortlieb basket (also waterproof) on the handle-bar for camera and other handy-stuff, and since this bag has also an inner pouch I thought to place all the electronic connectors inside there: The CA plugs, circuit breaker/fuse, and all splitters ingoing/outgoing connectors.

What do you think ?

There is no way i'd mount a battery anywhere but the triangle and thus roughly in line with the wheels and in the center of the bike.

A rear rack up high is literally the worst place to put a battery because physics.
Panniers are slightly better, but when you dump your bike on it's side, you'll realize that wasn't a great place to put the batteries.

Handlebar mounting 12kg = steering nightmare.

If i was building a long range touring bicycle, i'd be looking at a longtail or midtail with front suspension and literally as much battery crammed into the center as possible. Such a bike would have no issues jamming hundreds of miles worth of capacity.

neptronix said:

Panniers are slightly better, but when you dump your bike on it's side, you'll realize that wasn't a great place to put the batteries.

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The panniers are large and the inner-pocket is deep so the battery would be just a bit higher than the dropout.
I will use a bi-pod kickstand so there would be no need to lay them on one side. Even if they fall, the contents of the bag (clothing, sleeping bag) would be protecting them as they would be on the inner side. (unless you only carry nails and sharp metal cubes)
Even before I had motors and I was touring in the same 4 bags configuration, I would never purposely lay the bike on it's side with the panniers - It would be a nightmare to lift back up...

neptronix said:

If i was building a long range touring bicycle, i'd be looking at a longtail or midtail with front suspension and literally as much battery crammed into the center as possible. Such a bike would have no issues jamming hundreds of miles worth of capacity.

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I totally agree with you in terms of ergonomics and physics, but, If you want to be versatile and have the ability to go inside buses/car racks/all kinds of hotels or hostels, a longtail/midtail can literally leave you stranded and stuck without being able to be pulled away or to be able to fit the bike into your hotel-room. (And elevators tend to be small...)
I can give a solid example: On my non-motorized bicycle tour around Norway with a regular 700c bike, there were times I wished I had a BikeFriday 20inch folding bike. Small 20inch is too much, so I think the 700c is a good compromise and it has much more potential storage space.
The triangle space will be used for mounting 2 Satiator-chargers: The frame already has 2 water bottle eyelets, and the satiators are a heavy object too. (otherwise they are in the panniers)
Not as heavy as a battery of course, but it makes a good use of the space for the weight.
Why 2 Satiators? When you have electricity only once per 100-200Km, you need to make the most of it...

Well, i'm referring to the time you're going to not purposely putting the bike on it's side at 20mph.. catch my drift?

If you're gonna be in hotels and whatnot, yeah.. a longtail is a pain in the ass.. or any cargo bike.. ok, let's rule that out.

What i would be doing in your situation is packing the most watt hours in the triangle possible, as well as using the most efficient and simple motor configuration money can buy. or perhaps you chose redundancy and go with 2 geared motors so that if one motor goes bust, the other still lives.

There are a couple 3500mah 18650 cells on the market today. You could jam 2kw-hrs ( or more ) into a bike frame with these if space is optimized properly. I would add another 0.5-1kwhr to the top tube because this is a pretty safe spot also.

Only downside to this is that it's going to require custom pack construction of course..

If i was on a long bike tour, that's how i'd do it though, because whatever design you go with, you're gonna have to deal with it for a lot of miles.

There is a screaming need for a REMOVABLE triangle frame pack solution that is rigid an that could have a keylocks.
The biggest dowtube battery I could find was this : https://endless-sphere.com/forums/viewtopic.php?f=14&t=88415
Still too small to my taste (13S5P max).

Somebody has to come up with a removable 14S8P removable key-lockable battery case for the triangle. Frog pack, rearpack and too small downtube pack are a very limiting factor for range and they really mess up with center of gravity and give poor handling.

neptronix said:

Well, i'm referring to the time you're going to not purposely putting the bike on it's side at 20mph.. catch my drift?

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Yep... The panniers would provide less protection than the triangle, but it still be protected as the contents of the bag would hit the ground first - mostly clothes and other soft items.

neptronix said:

What i would be doing in your situation is packing the most watt hours in the triangle possible, as well as using the most efficient and simple motor configuration money can buy. or perhaps you chose redundancy and go with 2 geared motors so that if one motor goes bust, the other still lives.

There are a couple 3500mah 18650 cells on the market today. You could jam 2kw-hrs ( or more ) into a bike frame with these if space is optimized properly. I would add another 0.5-1kwhr to the top tube because this is a pretty safe spot also.

Click to expand...

I prefer not to spend big bucks on another new pack when I already have dozens of those prismatic A123 cells laying around. I bought them second hand for a bargain from a motorized vehicle dissassembly and they are still like new. In fact, they are going to outlive any pack if I would have decided to buy one now.
The second reason, As Matador wrote, is the screaming need for removable triangle frame pack. Not only from stealing perspective, but mainly from the above reasons: If it's removeable, I can mount the bike on a car rack, lift it up, fix flats very easily, access tiny-elevators/stairways etc...
I already have a VERY FAST daily-commuting full suspension bike with 2 motors. The battery is naturally inside the triangle at the spoken speeds so it's safe and comfortable, but when I had a flat once - in the middle of nowhere I couldn't solve it on my own as the pack was fixed so the bike was too heavy to lift. (11Kg of battery)
Eventually I got a lift with a car home, as it was quicker than asking the driver to hold the bike while I disassemble half of the bike to fix it. (The car-rack couldn't work because the triangle was full with batteries, so we just lift it and pushed it together into the trunk. (big car - I was lucky)

neptronix said:

If i was on a long bike tour, that's how i'd do it though, because whatever design you go with, you're gonna have to deal with it for a lot of miles.

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The A123 prismatic cells are the perfect candidate for hauling endless amount of miles and charge cycles. Using a non-A123 pack would mean it would already lose half of it's life (or more) at the end of such long distance touring trip, assuming I can charge the 79.2*20=1584Wh pack up to 2-4 times per day when I am in electricity accessible areas.

Frame is best

cwah said:

Frame is best

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Perhaps you didn't follow the entire thread: I totally agree that the triangle space is the best, but there must be a solution of how to make the pack removable. Otherwise, it creates serious limitations when using this bike on world touring.
Did anyone make their triangle packs removable ?

I did this:
[youtube]https://youtu.be/t9vuGRYKaQI[/youtube]

Its removable. I take it out for charging

cwah said:

I did this:
[youtube]https://youtu.be/t9vuGRYKaQI[/youtube]

Its removable. I take it out for charging

Click to expand...

There are no close-up pics or explanation. Just one picture with the entire bike.
Judging by that single pic that mounting looks a bit dangerous

That weight in each pannier is not that bad. But the bike won't be as ninble, or handle higher speeds as well as a lighter battery that does fit entirely in the frame. But better to put the other gear on top, vs the batteries, for sure. Battery in the bottom, then other, lighter stuff on top to fill them.

RE the longtails. Full size longtails will not fit a car bike rack, or a bus rack. But a mid length longtail might. I ended up building this bike so that I could carry 2000 watt hours of battery in the frame, AND fit on my cars bike rack.

Till it burned in my garage, it was the best handling bike I ever owned, when loaded down. The battery weight concentrated near the seat post is why.

Thinking outside the box or frame .... since your goal is touring have you considered a trailer like the Burley Travoy? This would allow you to split your battery with a smaller frame pack for shorter trips and a large trailer pack for the long touring segments. You could put one set of the Ortlieb classic panniers on the trailer (and it handles well on stairs as well).

https://endless-sphere.com/forums/download/file.php?id=191347

LewTwo said:

Thinking outside the box or frame .... since your goal is touring have you considered a trailer like the Burley Travoy? This would allow you to split your battery with a smaller frame pack for shorter trips and a large trailer pack for the long touring segments. You could put one set of the Ortlieb classic panniers on the trailer (and it handles well on stairs as well).

https://endless-sphere.com/forums/download/file.php?id=191347

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I would wish to do it, but two reasons prevent it:
1. In some countries, it is illegal to cycle on roads with a trailer of any kind. (or it would be suicidal to have one... Try Italy or Greece for example)
2. I would be limited to a slow, VERY slow speed with the trailer you attached. Once in Norway I've had a two 16inch wheeled trailer box with lots of space, but that thing was severely limiting my speeds and it was another issue to remember while manoeuvring narrow streets/turns and such. (I was much wider and longer)

The Travoy (and it's two competitors) handle differently than most other Bicycle trailers. As I have never been to either of the two reference countries I am not qualified to make comments on such local laws. I have had the privilege to visit some other European countries. Based on my experience there I do not feel that the Travoy would be much of an additional encumbrance even in some of the narrow back streets I saw in some small French villages. With its almost vertical stance close to the rear wheel of the bicycle it adds relatively little length. With the pivot point directly behind the seat it trails very well. I regularly travel at speed up to 20 MPH with my Travoy fully loaded with groceries. I am hardly aware that it is back there. There is not another bike trailer that I consider using in Houston's traffic.

... but it was only a thought

Well, I must say you all were right! The battery doesn't feel secure in those bags...
It's not the quality of the bags but due to the fact that a battery is a high density object.

So I went back to the triangle idea:

Here are 15 of those A123 20Ah prismatic cells, stacked together as 15S group.
That's the maximum you can fit before pedal clearance can be an issue.
As you can see, there is still room for mounting the bike on a car rack!
Here is a picture from another angle demonstrating the pedal clearance limit:


Since I need at least 9-10 more cells (Capacity wise and voltage wise) I need to find a solution for those...
Here is one of the ideas:

Here the battery is secured on the internal side of the rack. There is an identical battery on the other side of course. Each pack is 5S, making it a total of 25S and 82.5V 20Ah. The center of gravity is low, the battery is protected by the rack, and I can mount the panniers on the external side with no problem.
Here is another view of it:

What do you think of this idea?

Another option, which I already did successfully on my full-suspension city cruiser, is to mount the remaining packs on the stem of the handlebar, like this:

Although over there is was only 6 cells, but I assume 10 (and 2kg increase) won't be a problem because:
The cells sit exactly on the axis of the handlerbar, minimizing their rotation inertia so there would be barely any handling issues. The front rack and it's panniers would introduce way more handling inertia. It also distributes more evenly the total weight of the bike: The rear would carry the bigger panniers. (The front motor is 7.5Kg H3525+ and the rear 4Kg ezee250rc).

Speaking of the ezee, I just love how it fits every bike as if I jsut changed a regular wheel-hub:
View attachment 2
Look how nicely the 10 speed 11-36 XT cassette sits!
I still wait for other modern motors to have such nicely done cassette-hub and PERFECT disc-rotor compatibility.

The tire is Schwalbe Big apple 700x60 to maximize the cushion and reduce the vibrations which are so dangerous with the amount of mounts and connections this bike will have. There is very little clearance left between the rear tire and the front derailluer:

It is in the granny gear position, showing that is no collision with the tire: It's 5mm from it, and 3-4mm from the derailluer.
The only drawback here is that I can't mount mud guards which are very important, unless I install an XTR derailluer which is rumored to be much skinnier.

I also realize that the bipod-kickstand can be used as a "jack" (car-jack) if I ever need to fix flats:


What do you think about all this?
I now wonder if the 15S frame pack can be made removable. Are there any multi-use cable ties? Ones which are DESIGNED to be opened/locked. (I know to open the plastic ones with a flat head screw-driver)

Are there any multi-use cable ties? Ones which are DESIGNED to be opened/locked.

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Hook and Loop (aka Velcro) Cinch Straps. They make them in lengths from 6 to 60 inches (15 to 150 cm) long.
https://www.amazon.com/dp/B01G4IVLC2
https://www.amazon.com/dp/B004FV0Z8M

Some folks can pedal normally with a battery in the frame, and some can't. Any issues, however small, that a frame mounted battery creates for pedaling will become extremely problematic when you spent whole days on the bike. (If you pedal.)

Self-supported cycle tourists typically carry a lot of stuff, and they do it the way you suggest-- distributing the load among front and rear panniers. They don't usually have stuff in the front triangle even though such bags exist.

Soft bags like yours serve as shock absorbers for heavy and noncompliant loads like batteries. That's not only easier on the batteries, but easier on the bike's wheels and other moving parts.

If you can hang another pouch inside each pannier, using the panniers' mounting hardware, then you can use that pouch to hold the battery inboard of the rest of your stuff, and above the bottom of the pannier. That would allow your other items to protect the battery somewhat in case of a tipover or crash.