where will u get 43v BMS? Or U wanna try with 48v BMS?Hey there, if bafang is late at providing the btf014, I might want to go for diy. Do you think a 12s1p micro battery would work? Just enough to do few kilometers in eco mode!
I’ve just clicked on the first I saw, bit you can relatively easily find it on Aliexpresswhere will u get 43v BMS? Or U wanna try with 48v BMS?
I have been thinking about this same thing. A custom battery would be lighter and the size you choose yourself(that can fit in the frame).I’ve just clicked on the first I saw, bit you can relatively easily find it on Aliexpress
€ 15,76 | BeMuchSafer-Batterie BMS pour E-Bike E-Scooter E-Motorcycle, 10S, 12S, 13S, 30A, 36V, 43.2V, 48V, 43V, 10S30A, 12S30A, 13S30A, DIY
10.94£ |Bms 13s 48v 30a Separate | 36v Bms 10s 30a | 10s 48v 30a Bms - Battery Accessories & Charger Accessories - Aliexpress
Smarter Shopping, Better Living! Aliexpress.coma.aliexpress.com
I‘m not the expert in this, but my understanding is that its beneficial (depending on the cell type) to have some parallel batteries to ensure You can draw enough amps from the pack. For example the Samsung 21700 50E is rated continuous discharge rate 10A. If You create a parallel pack 2P, You can draw 20A. I doubt a 12S1P pack is any good for ebike application. Hope that makes sense @Waynemarlow?Hey there, if bafang is late at providing the btf014, I might want to go for diy. Do you think a 12s1p micro battery would work? Just enough to do few kilometers in eco mode!
Yeah you’re totally right. I remember now, I used to build dronesI‘m not the expert in this, but my understanding is that its beneficial (depending on the cell type) to have some parallel batteries to ensure You can draw enough amps from the pack. For example the Samsung 21700 50E is rated continuous discharge rate 10A. If You create a parallel pack 2P, You can draw 20A. I doubt a 12S1P pack is any good for ebike application. Hope that makes sense @Waynemarlow?
I think the CEF50 is better for big DIY batteries, the frame is bulkier than the lce930, which is why I prefer the LCHave anyone done some testing?
What ranges can we expect from the m820 and how small is the tube?
Would it be possible to DIY a larger "soft" battery or are we restricted by the size and form?
Yes, the C is the discharge current, and 1C meaning the discharge current being equal to the capacity?You also have to remember the "C" rating, if you remember from drones.
Not quite, good battery build will ensure that interconnections will handle any load between cells.So you can have a 20ah battery but only able to discharge at 1 amp because the connections inside the battery from one cell to the next can only handle 1 amp as an example
I would largely agree however in the world of practicality and production cost you are not going to produce a new design of cell with 0.001gm lighter materials just for the Bafang M820. Instead the cell manufacturers are going to stick with their production line where they make millions of cells, all of the same form and shape. What material that goes inside is just a chemical recipe designed whether the manufacturer wants capacity or C factor ( yes there is a lot more involved than that, but that’s best discussed on another forum where proper battery whizz kids hang out )Sorry that is not true at all. If you don't need a high "C" rating it is perfectly proper to design a battery with smaller capacity connections because they are lighter. The M820 only has an XT30 connector so the max current a XT30 can handle safely is 30 amps. So that requirement is very different than a full power motor that might require 60amps.
36v does not limit your cell choice. They all use the same cells. The only difference is the ampacity of connections and their weight.
What bms are you using and how do you connect it to the can bus of the motor?I’m making my own battery, 36V, 30 cells, 378WH and should weigh around 1850kg.
I might go for a larger battery later but want to keep the weight down to start with
Be aware that the higher current cells voltage can sag badly in the later stages of discharge. This as we have found from actual use will trigger either the battery BMS, the bikes low voltage threshold detect or simply will mean the motor will go into reduced Watts output, much earlier than an actual fully discharged battery.but if you just get a higher current cell like the 50s you can do 25a and still retain 5ah of capacity
The BMS is a Daly I have used them on my battery builds, the power cable connects to the XT30 plug on the motor.What bms are you using and how do you connect it to the can bus of the motor?
So this is the DIY 10S5P 18650 / 36V / 17.5 Ah / 630Wh battery You’re gonna use?The BMS is a Daly I have used them on my battery builds, the power cable connects to the XT30 plug on the motor.
See the link on how to build a battery
How To Build A DIY Electric Bicycle Lithium Battery From 18650 Cells
www.ebikeschool.com
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Looks very nice, I was planning something similar. Only the can bus confuses me. What is it for, if you don’t need it?The BMS is a Daly I have used them on my battery builds, the power cable connects to the XT30 plug on the motor.
See the link on how to build a battery
How To Build A DIY Electric Bicycle Lithium Battery From 18650 Cells
www.ebikeschool.com
I was planning a 36V, 40 cells(21700), 720Wh. Weight per cell around 70g, so with bms and tape/packing material it should be around +3kg. I think this is maximum that can fit inside the frame, calculating from the size of the bafang 410Wh battery.I’m making my own battery, 36V, 30 cells, 378WH and should weigh around 1850kg.
I might go for a larger battery later but want to keep the weight down to start with
So this is the DIY 10S5P 18650 / 36V / 17.5 Ah / 630Wh battery You’re gonna use?
No the photo is another battery I built, I going build a 10s3P using 30 LG MJ1 18650 3500mAh 10A Battery cells.So this is the DIY 10S5P 18650 / 36V / 17.5 Ah / 630Wh battery You’re gonna use?
Yep sounds like a plan, it would be a tight fitI was planning a 36V, 40 cells(21700), 720Wh. Weight per cell around 70g, so with bms and tape/packing material it should be around +3kg. I think this is maximum that can fit inside the frame, calculating from the size of the bafang 410Wh battery.
I would like the 36V motor for better compability with standard bottle-batteries, but a 43V battery would be an exact fit.Yep sounds like a plan, it would be a tight fit
I find the 18650 are more compact, but it depends on space available 3 x 21 diameter cells would be around 70mm wide, it would pay to get your frame first before building the battery or start with a smaller one first, it’s great having multiple battery’s, I have a 900wh for my big rides, but prefer a smaller battery for weekend riding
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