How to secure the battery to the bike

alexscard

10 W
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Aug 7, 2021
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I'm going to buy a big battery (around 1500wh), and then i have the problem of how to safely attach it to the bike.
I have bought a huge triangle bag, and this could work but, i want to change bike and buy a full ammortized One, and in this case the frame space triangle would be too small for the 50*50*30cm bag.
Also, if i could secure it to the frame in a rigid way, also the Dynamic of the bike would be Better.
Where i can find o i can ask to manufacture a rigid case to put over the frame, on the top, so to put the battery inside it?
 
We must see the exact frame you're going to use. As before you start buying things find out what frame you have or are interested in and where all the components are going to fit mid Drive ,geared motor, direct drive motor. I had a em3ev triangle bag it was for 18650 cells I thought I could cheat it and use 21700 cells. But putting 120 cells in a triangle em3ev bag it didn't work because of the height of the cells is extra room. I had to have my bag cut open and a piece of leather added all the way around.. a big battery weighs a lot should be supported from the bottom.
 
ok i attached the picture of the bike i'd like to buy and where i'd want to put the battery

bike:
https://www.decathlon.it/p/mtb-st-540-s-blu-arancione-27-5/_/R-p-301117?mc=8500761&c=BLU
battery:
https://www.akkushop-24.de/Lithium-Ionen-Akku-72V-20Ah-1440Wh-Akkupack-incl-50A-BMS-Ladegeraet-fuer-Scooter-E-Bike-Pedelec
 

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alexscard said:
ok i attached the picture of the bike i'd like to buy and where i'd want to put the battery

bike:
https://www.decathlon.it/p/mtb-st-540-s-blu-arancione-27-5/_/R-p-301117?mc=8500761&c=BLU
battery:
https://www.akkushop-24.de/Lithium-Ionen-Akku-72V-20Ah-1440Wh-Akkupack-incl-50A-BMS-Ladegeraet-fuer-Scooter-E-Bike-Pedelec

Assuming no pedaling, right?
 
following law of physics - low center of gravity , as low as possibly for stable ride.
placing weight of battery even on bike luggage rack makes it unstable for me.
 
I also Need to pedal..
About the height, i know that the lower the better, but the room is what it is..
 
Yeah, you got a problem there. You want to carry a huge battery in a good place on an MTB. Its way too big for the triangle, way too big for a rear rack, and way too big for the top tube. Unless you got legs 4 feet long anyway. You are planning a disaster.

What you need, is a different bike. A cargo bike, if this is going to be street ridden. Or a battery that can be split in half, to carry some, less than 10 pounds on a rear rack, and the rest either in the frame, or on a front rack, or both.

If you are going dirt riding, you need to buy a frame that can carry the bigger battery. Something like the stealth bomber frames. There are sources for this type frame now. Then the battery needs to be bought that fits the box on the frame.

I got real tired of dirt rides that only lasted 30 min, then back home to change batteries. Tired enough of it to just buy a gas motorcycle, and get 3 hours or more of ride time. But I can't ride those same MTB trails with it. Worked for me because I live in dirt bike heaven, with hundreds of miles of dirt roads I can ride within a few miles of my house.
 
yeah it's hard.
right now, this is my bike, and this is the bag i bought to place the battery inside https://it.aliexpress.com/item/1005001905799469.html?spm=a2g0s.9042311.0.0.5d9d4c4dn58AFD
it's big enough, but i already use a bag for my current battery, that is a 800Wh battery, and i know that is not very good for the dynamic of the bike. the battery is a heavy object, and when it moves the bike somehow is affected by it.
if i don't find any way to adapt the new battery to a full suspended bike, i'll just stick with this current bike without the comfort of a rear suspension and amen..
 

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This has come up before, but lower CG with the battery isn't already better.
Too low makes the bike sluggish entering turns, and makes it lose the feeling of the bike moving around under the rider.
I experimented a bunch with different mounting heights, and I liked it on top of the top tube.
KIMG0456.jpg

It's hard to tell from the pic, but that battery rack is a razor scooter body with the steering removed, sitting on the top tube with padding in between, with the seatpost stabilizing it. There's not even any fasteners.
 
Voltron said:
KIMG0456.jpg

It's hard to tell from the pic, but that battery rack is a razor scooter body with the steering removed, sitting on the top tube with padding in between, with the seatpost stabilizing it. There's not even any fasteners.

Haha I love it!

It reminds me of the umm, expedient battery mounting I used while experimenting with a single wheel pusher trailer.

IMG_20150408_160049.jpg
 
People who find low CG sluggish, simply haven't learned to counter steer.

But yeah, nothing wrong with the top bar carry in terms of handling. Its just when you need to stand over the bar at a light, and your feet don't reach the ground that its a bit awkward. It just works less good on tall bikes, like FS MTB's that because of suspension, are 4" taller. I found a front handlebar mount battery worked good, at 8 pound or so. So I carried 48v 20 ah, with 8 pounds on the front, and 8 pounds on the rear rack.

Its his idea of a single huge brick that is causing problems.
 
Well, we'll just have to disagree on that.
I've tested it plenty, with different mounting positions on the same bike, and on multiple different frames, often with the throttle locked so I could initiate into turns and then let go of the bars to see how much it wound in, etc
I come from a testing and tuning background in flying and sailing, so analyzing handling is kind my thing, and I def know how to countersteer! Lol

With the CG too low, it resists the initial twitch of the front wheel that should get the bike leaning the other way, so when there's say a pothole coming, the bike loses the feeling of moving back and forth under the rider during a quick swerve.
Then, in high speed sweeper turns, the low CG wants to sling to the outside of the turn, making the bike want to wind into the turn tighter and tighter.
So too low is sluggish to initiate, and spirals in at high speed.

Real low makes it track well for riding no hands, so there's that...
 
Chalo said:
It reminds me of the umm, expedient battery mounting I used while experimenting with a single wheel pusher trailer.
Speaking of which, I really should work out something of a bit more permanent nature but if it ain't broke ....
Temp Bat Mount.JPG
That 1/4-20 bolt and Wingnut is where I connect the Burley Travoy trailer.
 
Yes, better is not too low weight, But you can learn to deal with it quite effectively. Many have no clue that they countersteer to stay balanced on a bike, till for some reason they don't. As you move into large scooters with low cg, you do have to pay more attention and counter steel harder, and earlier. Notice I did not ever say low cg is better. only that you can learn to deal with it so it does not crash you.

I feel that too much weight in any wrong place on a bike will often make the frame twist, which really affects handling. If you gotta wait for the frame to un twist after initiating countersteer, then that IS sluggish. Panniers make the tail wag, if overloaded, and overloaded might be not that much weight, if the bike frame is not made for panniers, or weight anywhere else on the bike.

But Ideal placement of the weight to me, is pretty much center of a bike frame triangle, if you have one. I don't advocate strapping 20 pounds under the down tube, or on top. 8 pounds, you can put just about anywhere you like on a reasonably strong bike. Bike shaped object, you are just screwed, pedaling alone makes the tail wag.

Again, his real problem is the huge brick of the battery. He needs a frame designed around a brick, to carry a brick.
 
I was more just rebutting the low as possible is better theories.

But re BSOs with giant blocky overweight batteries.... I still liked high CG better 🤘😂
112.JPG

But it sure still responded to little nudges and body English like a little trained but ugly pony 🤣
The sound is terrible btw, but this is dodging rocks in the trail, deep root ruts, bumpy bridges and dangerous trail edges, and tracking like a champ👍
[youtube]nD3s0gEmiLs[/youtube]
 
look for an older used bike if you need full suspension. Kona kockapoo ,Giant has some. What motor ? How many amp controller ? Where's it going to go ? Make a cardboard box the size of each item and see how it fits on your bike. Yes before you buy. they will all fit in your backpack as you go shopping or looking for a used bike. How fast do you want to go ?
https://endless-sphere.com/forums/viewtopic.php?f=6&t=37283&p=687392&hilit=trek#p542147
 
Anything over 20 mph full suspension is the only way to go. I recommend a hobby motor and VESC. You can now push a small motor up to 5 kW.
Controller: https://forum.esk8.news/t/little-focer-84v-5kw-vesc-based-controller/50110/641
Motor: https://alienpowersystem.com/product-category/brushless-motors/80mm/page/2/
 
there are lots of people that are not motorized that ride with leg power faster then 20mph on rigid road bicycles, lance can do 7w/kg and he stated when power meters came out 500w for a half hour decades ago was common for short day races

Ecyclist said:
Anything over 20 mph full suspension is the only way to go. I recommend a hobby motor and VESC. You can now push a small motor up to 5 kW.
Controller: https://forum.esk8.news/t/little-focer-84v-5kw-vesc-based-controller/50110/641
Motor: https://alienpowersystem.com/product-category/brushless-motors/80mm/page/2/
 
did you buy that from this guy https://endless-sphere.com/forums/viewtopic.php?f=3&t=62231&start=7425#p1676132

Voltron said:
I was more just rebutting the low as possible is better theories.

But re BSOs with giant blocky overweight batteries.... I still liked high CG better 🤘😂
112.JPG

But it sure still responded to little nudges and body English like a little trained but ugly pony 🤣
The sound is terrible btw, but this is dodging rocks in the trail, deep root ruts, bumpy bridges and dangerous trail edges, and tracking like a champ👍
[youtube]nD3s0gEmiLs[/youtube]
 
calab said:
there are lots of people that are not motorized that ride with leg power faster then 20mph on rigid road bicycles, lance can do 7w/kg and he stated when power meters came out 500w for a half hour decades ago was common for short day races

Ecyclist said:
Anything over 20 mph full suspension is the only way to go. I recommend a hobby motor and VESC. You can now push a small motor up to 5 kW.
Controller: https://forum.esk8.news/t/little-focer-84v-5kw-vesc-based-controller/50110/641
Motor: https://alienpowersystem.com/product-category/brushless-motors/80mm/page/2/
If your goal is to squeezy maximum performance (read speed) out of what you have and feel every pebble on the road with your ass go for it. I have an old criterium Cannondale road bike. It's very fast and it's hanging on the wall of my garage and collects dust for the last 20 years. That old carving board looks cool too. :D
Bike.jpg
 
Ecyclist said:
If your goal is to squeezy maximum performance (read speed) out of what you have and feel every pebble on the road with your ass go for it. I have an old criterium Cannondale road bike. It's very fast and it's hanging on the wall of my garage and collects dust for the last 20 years.

There's a whole lot of room between a very rigid racing bike with a masochistic riding position and tires the size of macaroni, and some needlessly heavy, sloppy, noisy, complex, imprecise-riding, expensive, soon-to-be-unsupported suspension bike.

A bike with 2" wide tires, a sprung saddle, and a comfy riding position is plenty usable at speeds up to about 30 mph. It's not what they're best at, but they can do it (and they won't definitely be garbage after a few years of use like a suspension bike).
 
Chalo said:
Ecyclist said:
If your goal is to squeezy maximum performance (read speed) out of what you have and feel every pebble on the road with your ass go for it. I have an old criterium Cannondale road bike. It's very fast and it's hanging on the wall of my garage and collects dust for the last 20 years.

There's a whole lot of room between a very rigid racing bike with a masochistic riding position and tires the size of macaroni, and some needlessly heavy, sloppy, noisy, complex, imprecise-riding, expensive, soon-to-be-unsupported suspension bike.

A bike with 2" wide tires, a sprung saddle, and a comfy riding position is plenty usable at speeds up to about 30 mph. It's not what they're best at, but they can do it (and they won't definitely be garbage after a few years of use like a suspension bike).
I don't know what do you mean by garbage after a few years. I have, at this point, 5 full suspension bikes, they are all easily over 10 years old and all of them running like new. On the other note a good bike with thick tires and a sprung saddle will get you from point A to point B, but what about electronics and battery? These things hate vibrations. How many cars without suspension are out there? Maybe you should remove suspicion from your car and see how it feels? I bet it will last forever sitting in your garage.
What is interesting that I posted a photo of my bike with a good battery mount and I don't see any questions about that mount. This thread is about "How to secure the battery to the bike" isn't it?
Maybe some of you ride an electric bike without suspension and now you trying to justify your choice. It's OK I have one like that as well, but I still think that if you have a choice you should go with full suspension. A bike that is capable of going 20 mph under power can go over 40 downhill, but without suspension it sucks.
Xiongda on Gekko 3.JPG
 
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