what's your fav/ideal battery? case style/shape, nS,nP, mount location, BMS, cell, etc etc

[mindgames11]

What's your "favorite" (vague and unqualified), or ideal for a distinct application battery style?
what I use is somewhat less defined by what I would take given infinite choice, but what I have/get cheaply. I have managed to find nearly every battery I have or bought them from crack heads for insanely little. almost all 18650's MJ1. I have one segway g30 60 cell Im taking apart, two random 48V batteries that clipped into downtubes etc. I find myself liking 48v, and silverfish aluminum cased batteries (since I've found one and have bought two cases for like $20 each- 13s5p). I have a rough time mounting to bikes or scooters- sometimes I'll just build a bucket-shelf onto a tube and use 1 inch strap webbing. In a pinch I'll strap one to a rear or front fender. I use JiabaiDa 8-14 cell 30a (I think) BMS that are ~$17 aliexp.
I use a 4s LIPO RC 6800mah 80C along with a 99 gears spot welder when making.
I must have nearly 2000 cells between all the assembled/disassembled packs.

what do other people use? what are your likes/dislikes about any particular aspect of batteries, how they integrate with devices, etc?

 

[Hummina Shadeeba]

I have a simple Velcro triangle shaped box I haven’t used yet but liking its simplicity and adjustability.

Having the battery in the frame front triangle is definitely preferred. (I still think higher is better than lower for handling sake).

I like to minimally pot the battery for the inevitable drop or crash. (60-70D duro polyurethane)


Lately been 3d printing boxes that bolt to added threaded holes on the frame

Still like lifepo4 so I don’t have to worry as much and will balance externally.

 

[Risky Rob]

I have a simple Velcro triangle shaped box I haven’t used yet but liking its simplicity and adjustability.

Having the battery in the frame front triangle is definitely preferred. (I still think higher is better than lower for handling sake).

I like to minimally pot the battery for the inevitable drop or crash. (60-70D duro polyurethane)


Lately been 3d printing boxes that bolt to added threaded holes on the frame

Still like lifepo4 so I don’t have to worry as much and will balance externally.

I moved a heavy battery from a triangle bag hanging from the top bar to a mount on the bottom bar. That made a huge improvement in stability and handling.

 

[A-DamW]

what do other people use? what are your likes/dislikes about any particular aspect of batteries, how they integrate with devices, etc?

I find building my own batteries just takes a lot of time.
I use whatever I have around, whatever works for the application at hand.
Most of my battery needs are on cargo bikes/trikes with enough room to handle blocky shapes.
Here is a 196 cell, 1.7kWH 14s14p I am building in a DeWalt drill case.

 

[Zambam]

Having the battery in the frame front triangle is definitely preferred. (I still think higher is better than lower for handling sake).

Higher is better than lower for handling? How would you explain that?

 

[Hummina Shadeeba]

I moved a heavy battery from a triangle bag hanging from the top bar to a mount on the bottom bar. That made a huge improvement in stability and handling.

Higher is better than lower for handling? How would you explain that?

Glad you asked and it’s a debate I have with a friend and he insists I’m wrong. My understanding of how it works and what the effects of the mass location I gathered here on es and in my looking at motorcycle racing bike design through time. Maybe I can find the one great source I found and will post it here.


looking at race bikes these days theyre designed with the mass centered. They could lower it, and in the past that’s been tried, but it hinders the speed at which you can turn and also the rear wheel is more likely to lose traction when accelerating. (We don’t have the power to lose traction from crazy acceleration but the quick turn-ability is what I consider a good hanging bike.). If u view the bike from the front while turning it is pivoting around the center of the mass of the bike and rider and to make that turn happen quicker you want the mass as condensed in that central location as possible as then you have less work to move it and can happen faster

But then the labels of “best handling” and “stability” are different and even what they individually mean are vague.


I understand stability on a bike being analogous to trying to balance a pencil in one’s palm vs doing the same with a ruler. With the mass raised it’s more stable.


I think race motorcycles would have their mass even higher if it weren’t for the extreme braking and acceleration causing them to flip over

 

[Risky Rob]

Grok says yes, mounting a heavy battery (or any heavy component) as low as possible almost always improves riding stability on a motorcycle, bicycle, e-bike, or even a go-kart/scooter. Here’s why and how much it matters: Key Physics Reasons

1. Lower center of gravity (CoG)
   The most important factor for stability, especially in corners and during quick direction changes. A lower CoG increases the bike’s resistance to tipping over (higher roll threshold) and makes it feel more planted.
2. Reduced polar moment of inertia (yaw inertia)
   When the heavy battery is low and close to the bike’s centerline (not high up on a rear rack or under the seat at head-tube height), less mass is far from the steering axis. This makes steering quicker and lighter without making the bike feel nervous.
3. Better front/rear weight distribution
   On many e-bikes and electric motorcycles, placing the battery low in the frame (often in the downtube or a “skateboard” position under the rider) shifts weight downward and slightly forward compared to older high-mounted packs. This usually improves trail braking stability and reduces wheelies under hard acceleration.

Real-World Examples

• Zero Motorcycles, Energica, LiveWire: All moved batteries to the absolute lowest point in the frame years ago specifically for handling benefits. Riders consistently report these bikes corner more like lighter ICE sport bikes despite weighing 500+ lbs.
• E-MTBs (e.g., Specialized Levo, Trek Rail with Bosch or Shimano EP8): Batteries integrated low in the downtube transformed handling compared to 2015-era bikes with batteries on or above the down tube.
• DIY e-bike conversions: Moving a heavy 52V 20Ah pack from a rear rack down into a triangle bag or frame mount dramatically reduces top-heavy feel and high-speed wobble.

How Much Difference Does It Make?

• Dropping a 15–25 lb (7–11 kg) battery 8–12 inches (20–30 cm) lower can reduce the overall height of the center of gravity by 2–4 inches on a typical e-bike or electric motorcycle.
• This often translates to 10–20% higher cornering lean angles before scraping or losing traction, and a noticeably more confidence-inspiring feel above 40–50 mph (65–80 km/h).

Caveats

• If the battery is mounted too low, you lose ground clearance (relevant for off-road or sport bikes with high lean angles).
• On some designs, extreme low mounting can slightly hurt straight-line high-speed stability (makes the bike more sensitive to rider weight shifts), but this is rare and usually only noticeable above 100 mph.

Bottom LineYes — for 99% of real-world riding (street, commuting, trail, even track days under 120 mph), mounting a heavy battery as low and as centrally as practical is one of the single biggest handling upgrades you can make. Virtually every serious electric motorcycle and modern e-bike manufacturer now designs around this principle for that exact reason.

 

[docw009]

I think the must rugged case is the silverfish, but it is only useable on older commercial ebikes. The silver fish has accessible charge/discharge fuses and a robust power switch. Next is the wart-like Dolphin, which dates back over ten years. The really old ones are pretty water resistant, I doubt any new bikes use them. There are at least a half dozen Hailong styles, all with incompatible cradles. Their switches and charger jacks can be really cheap, and the cases can leak water. Haven't dealt with any of the modern in-frame mount cases.

Rack mount batteries are pretty expensive if you want the custom rack, An empty case and rack are more expensive than buying a cheapo battery/rack combo. I had a Lunacycle rack pack that I just mounted on a regular rack, but lost the ability to carry things unless I uses saddlebags, I recently got a rack/case for under $100. Error on the sellers part for giving free shipping, It's only a smaller 40 cell case. Filled it with 39 Samsung 30Q's. but have not got around to installing it on a bike. This will only be around 5 pounds.

I have built shrink wrapped packs too. Put them in boxes with plenty of padding, Built a couple that I put into water bottles to get away from the ebike look. Even did a 10S-1P 21700. About 150WH and still can spurt 20A.

I try to follow best DIY practices - cell holders or double insulation,, paper washers, balance BMS, name brand cells. My bikes are run at low power, so 30A max disharge is more than enough. My biggest battery is 48V15AH using 21700's.

 

[Hummina Shadeeba]

Grok says yes, mounting a heavy battery (or any heavy component) as low as possible almost always improves riding stability on a motorcycle, bicycle, e-bike, or even a go-kart/scooter. Here’s why and how much it matters: Key Physics Reasons

1. Lower center of gravity (CoG)
   The most important factor for stability, especially in corners and during quick direction changes. A lower CoG increases the bike’s resistance to tipping over (higher roll threshold) and makes it feel more planted.
2. Reduced polar moment of inertia (yaw inertia)
   When the heavy battery is low and close to the bike’s centerline (not high up on a rear rack or under the seat at head-tube height), less mass is far from the steering axis. This makes steering quicker and lighter without making the bike feel nervous.
3. Better front/rear weight distribution
   On many e-bikes and electric motorcycles, placing the battery low in the frame (often in the downtube or a “skateboard” position under the rider) shifts weight downward and slightly forward compared to older high-mounted packs. This usually improves trail braking stability and reduces wheelies under hard acceleration.

Real-World Examples

• Zero Motorcycles, Energica, LiveWire: All moved batteries to the absolute lowest point in the frame years ago specifically for handling benefits. Riders consistently report these bikes corner more like lighter ICE sport bikes despite weighing 500+ lbs.
• E-MTBs (e.g., Specialized Levo, Trek Rail with Bosch or Shimano EP8): Batteries integrated low in the downtube transformed handling compared to 2015-era bikes with batteries on or above the down tube.
• DIY e-bike conversions: Moving a heavy 52V 20Ah pack from a rear rack down into a triangle bag or frame mount dramatically reduces top-heavy feel and high-speed wobble.

How Much Difference Does It Make?

• Dropping a 15–25 lb (7–11 kg) battery 8–12 inches (20–30 cm) lower can reduce the overall height of the center of gravity by 2–4 inches on a typical e-bike or electric motorcycle.
• This often translates to 10–20% higher cornering lean angles before scraping or losing traction, and a noticeably more confidence-inspiring feel above 40–50 mph (65–80 km/h).

Caveats

• If the battery is mounted too low, you lose ground clearance (relevant for off-road or sport bikes with high lean angles).
• On some designs, extreme low mounting can slightly hurt straight-line high-speed stability (makes the bike more sensitive to rider weight shifts), but this is rare and usually only noticeable above 100 mph.

Bottom LineYes — for 99% of real-world riding (street, commuting, trail, even track days under 120 mph), mounting a heavy battery as low and as centrally as practical is one of the single biggest handling upgrades you can make. Virtually every serious electric motorcycle and modern e-bike manufacturer now designs around this principle for that exact reason.

I’m still not sold on lower being better for quick handling and I’ve found numerous sources saying otherwise.

Motorcycle Center of Gravity Motorhead Myths

Does a low center of gravity improve handling? Kevin Cameron says it depends on what kind of handling you are after and it isn’t the answer to quick-handling sportbikes.

www.cycleworld.com

How Motorcycles Carry Their Weight

How motorcycles carry their weight is a compromise that influences wheelie and stoppie resistance, turning and going straight. We explain how it all works.

www.cycleworld.com

Then again it depends on the goal and I more so think a quick turning bike has “good handling”.


I wonder exactly where grok is getting its info and the center of mass on a typical sport bike is pretty high

 

[99t4]

Grok says yes, mounting a heavy battery (or any heavy component) as low as possible almost always improves riding stability on a motorcycle, bicycle, e-bike, or even a go-kart/scooter. Here’s why and how much it matters: Key Physics Reasons

I'm going to call BS on Grok's simplistic answer.

First of all, COG affects a 2-wheeler much differently than a 4-wheeler (the go-kart it lumps into its explanation). The movement equation gets exponentially more elaborate with a 2-wheeler as you are dealing with pitch (rotation around the side-to-side axis), roll (rotation around the front-to-back axis) and yaw (rotation around the vertical axis), and the method to initiate and maintain turning is completely different than for a 4-wheeler.

Yet Grok is telling us that simply massing weight "as low as possible" is always an improvement? Where should this low weight source be located? Front? Rear? Center?

More Grok BS:

DIY e-bike conversions: Moving a heavy 52V 20Ah pack from a rear rack down into a triangle bag or frame mount dramatically reduces top-heavy feel and high-speed wobble.

The improvement from moving a rack-mounted battery to the frame triangle has to do with reducing the tail-wagging-the-dog effect of the weight hanging off the rear of the bike, on a (almost always) flimsy swaying rack.

Wasn't it Yamaha that tested a prototype GP racebike in the '70s with reversed locations of the gas tank and exhaust pipe in an effort to lower the COG? Quickly abandoned as the results were less than inspiring.

Grok sure made a compelling and appealing argument with conviction but it doesn't hold up to scrutiny.

 

[Risky Rob]

Read it again and carefully this time. Do you have a high mounted battery?

 

[Hummina Shadeeba]

.



Wasn't it Yamaha that tested a prototype GP racebike in the '70s with reversed locations of the gas tank and exhaust pipe in an effort to lower the COG? Quickly abandoned as the results were less than inspiring.

In the first link I posted above it tells of this. It’s a really interesting read on the history and physics.


I also remember reading somewhere on the forum that lean angle isn’t related to COM and I even remember seeing a YouTube demo of this with a simple model but can’t find it and all I read elsewhere tells otherwise

@Risky Rob

I think my battery is relatively high. I put it there with the understanding the bike roll axis is up there and getting more weight at that location means less it has to be moved and therefore it can be turned faster as the links I posted tell
But we’re likely talking about different things and ur talking about stability and I’m talking about maneuverability.

 

[zeccato]

Qui

Prismatic (rectangular) battery and various modifications to the bike

Nmc 58Ah 15s, for now I am also satisfied with the quality they seem to have, 420Eu including ship. and tax. After a few charges and discharges, they do not seem to need balancing, and the temperature seems stable; Cell: 0.86 kg; 27*148*95 mm + the pin. Alveolar polycarbonate on the sides...

endless-sphere.com