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Help with making a Lithium Ion Battery

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Posted · Original PosterOP

Hello, I am making an electric bike and the motor controller is a 1000w controller and will draw 48V at 20A. I am going to be using 52 cells with 13 in a series and 4 sets of those in parallel. I will be using Samsung 30Q cells with a 15A maximum continuous current.


I'm wondering if the batteries are able to safely output the required current and if what amperage rating of a Battery Management System do I need (Is 20 sufficient or do I need more?)?


Thanks for the help!

I have an Anet A8 as my project printer and a i3 MK3 for when I want things to work. 


I extrude my own filament and haven't saved a penny yet.



My PC:


CPU: Intel i7 8700k

Motherboard: MSI Z370-A Pro

RAM: G.Skill Ripjaws V (2x8GB) DDR4-3200

GPU: GTX 1070 Founders Edition (OC'd)

Storage: 2x 2TB Seagate 5400RPM, 128GB ADATA SSD

Power Supply: EVGA Supernova 750w  B2

Cooling: Noctua NH-D15. 3 Intake Fans, 2 Outtake

Case: Fractal Design Define R6


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Well iirc, the 30q can do 30 amps continuous (which is still insane to me for an 18650 form factor), so if you multiply that by the 4 you have in parallel, you have 120A CONTINUOUS of battery (super insane).  One important thing to note is fully charged, a 13s lipo/li-ion pack like this will by 54.6V, but a nominal voltage (so like under load or storage charge) of around 48-49V. Just make sure your controller can take that. Now let's circle to your controller really quick, 1000W at 48V nominal will be just under 21 amps pulled from the battery. That's assuming your motor will use all 1000W and that you're pulling all 1000W. Realistically, you won't be consuming that much power very often. Full throttle from a dig, or up a hill are the only two examples I can think of that could possibly pin the system. Every day cruising will use way less than that, I would guess around 200-400W, but I'm not sure on that number.


So all that to say a 20 amp BMS is more than likely fine, and if the system for whatever pulls more than 20 amps, most electronics can output maybe 10-25% extra of their rated current for a short period of time, usually 10s or less. 

disclaimer: I'm just guestimating on the output of the samsung 30Q cells. I can't exactly remember what they put out, and I read that you said they can do 15 amps continuous after I wrote the above ramblings. As I am a tired college student, I am too lazy to actually google the spec sheet of the Samsung 30Q, but I'm not too lazy to write this little disclaimer that I may have no idea what the fuck I'm talking about. I like to think I know what the fuck I'm talking about, but hey, you never know. 


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