Battery idea

Asandei

1 µW
Joined
Sep 17, 2021
Messages
4
Hi everybody,

I'm part of a young team based on Italy and we want to have some feedback on an idea.
I'm here to ask, after getting a lot of help from the forum, if you would be interested in a modular battery system that can adapt to a lot of scenarios, from e-bikes, scooters, e-moped, e-motorcycle or, if you want, even electric cars. The modules would be pretty small 18650 10s1p that could be stacked together either in series or parallel. The rated discharge would be 3C.

If you are interested just comment with what you think or new ideas that can fit in the project.
We would like to satisfy the needs of customers as much as possible.

Adding an additional info : the packs will have custom fused nickel strips
 
Asandei said:
The modules would be pretty small 18650 10s1p that could be stacked together either in series or parallel. The rated discharge would be 3C.
Don't rule out 2170s ... less expensive per Wh. Wouldn't it make more sense to have 10s2p modules whether 1860s or 2170s ? For those that need at least a 10s4p (ebike) it would be less expensive to buy one 10S4P than four 10S1P packs.

The exception is when no more than a 250W motor where a 36V (10s) is a city law (enforced). The thinking being that a 250W motor is just for motor assist (not pedal assist) where pedal power is the primary power. When a 250W e-motor assist is needed/appreciated pedaling up an incline so one doesn't need to stand-up when pedaling up a hill.
 
Asandei said:
If you are interested just comment with what you think or new ideas that can fit in the project.
We would like to satisfy the needs of customers as much as possible.
  • Temperature control. How will you keep your cells not only cool enough under load, but also warm enough in the cold, if they're in modules you can swap repeatedly? There's good reasons why battery pack swaps are only going on in China for cars.
  • How will you keep other cells safe, if some fool puts a fully charged back in series with one that's at 40% SOC?
  • Why 10s1p? That's a working voltage of only 37v.
  • How will the BMS function? Will you have one for every 10s1p pack individually? Will they "talk" to one another?
 
https://ebikes.ca/product-info/grin-products/ligo-batteries.html
https://ebikes.ca/shop/electric-bicycle-parts/batteries/36v-ligo-battery.html
LiGoHeader2[1].jpg
[youtube]zjaUeh3jbFM[/youtube]

Asandei said:
Hi everybody,

I'm part of a young team based on Italy and we want to have some feedback on an idea.
I'm here to ask, after getting a lot of help from the forum, if you would be interested in a modular battery system that can adapt to a lot of scenarios, from e-bikes, scooters, e-moped, e-motorcycle or, if you want, even electric cars. The modules would be pretty small 18650 10s1p that could be stacked together either in series or parallel. The rated discharge would be 3C.

If you are interested just comment with what you think or new ideas that can fit in the project.
We would like to satisfy the needs of customers as much as possible.
 
CONSIDERABLE SHOUTING said:
Asandei said:
If you are interested just comment with what you think or new ideas that can fit in the project.
We would like to satisfy the needs of customers as much as possible.
  • Temperature control. How will you keep your cells not only cool enough under load, but also warm enough in the cold, if they're in modules you can swap repeatedly? There's good reasons why battery pack swaps are only going on in China for cars.
  • How will you keep other cells safe, if some fool puts a fully charged back in series with one that's at 40% SOC?
  • Why 10s1p? That's a working voltage of only 37v.
  • How will the BMS function? Will you have one for every 10s1p pack individually? Will they "talk" to one another?

The temperature will be monitored but active warming it's still in evaluation because it will take too much energy from the battery. We are looking at a solution that will warm the cells only before charging (if needed)
We have chosen the 10s1p configuration because it's the voltage at which most e-bikes work and that means that a builder/manufacturer will just have to put the necessary number of parallels. In the future we will look at a 24 volt module.
Every module will have a bms that we are developing and they will be able to communicate between themselves and no problems will arise if modules with different voltages will be put together thanks to the BMS.
 
eMark said:
Asandei said:
The modules would be pretty small 18650 10s1p that could be stacked together either in series or parallel. The rated discharge would be 3C.
Don't rule out 2170s ... less expensive per Wh. Wouldn't it make more sense to have 10s2p modules whether 1860s or 2170s ? For those that need at least a 10s4p (ebike) it would be less expensive to buy one 10S4P than four 10S1P packs.

The exception is when no more than a 250W motor where a 36V (10s) is a city law (enforced). The thinking being that a 250W motor is just for motor assist (not pedal assist) where pedal power is the primary power. When a 250W e-motor assist is needed/appreciated pedaling up an incline so one doesn't need to stand-up when pedaling up a hill.

Using a 2P pack can sometimes lead to the module not fitting well in a few spaces.We have observed that in a few cases we have to lose 2 parallels instead of using 1. Unfortunately making a module that fit a lot of scenarios is pretty damn difficult.
 
Asandei said:
Using a 2P pack can sometimes lead to the module not fitting well in a few spaces.We have observed that in a few cases we have to lose 2 parallels instead of using 1. Unfortunately making a module that fit a lot of scenarios is pretty damn difficult.
Please mention the specifics of a "few Cases" where 2P didn't fit well in a few spaces, where instead a 1P battery was a better fit? Do you have photos showing why a 2P wasn't a good fit?
 
eMark said:
Asandei said:
Using a 2P pack can sometimes lead to the module not fitting well in a few spaces.We have observed that in a few cases we have to lose 2 parallels instead of using 1. Unfortunately making a module that fit a lot of scenarios is pretty damn difficult.
Please mention the specifics of a "few Cases" where 2P didn't fit well in a few spaces, where instead a 1P battery was a better fit? Do you have photos showing why a 2P wasn't a good fit?

I'm not gonna share pictures of the prototypes because they have a transparent case but I can tell you a few things. The module has an honeycomb structure and in a few cases, where the angles of the frames are pretty steep it's a nice fit for a 1p pack, but not for a 2p. Frames like DH and MTB ones with a rear suspension coming into the triangle are especially difficult ones. It's pretty easy to work around this features when making a single battery pack, it becomes harder when using modules
 
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