48v using 4 12V 280ah batteries with overkill BMS for 20kw electric propulsion

Josehoya

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Mar 18, 2021
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I’m building 2 strings of 48v battery banks for a 20kw electric motor for a sailboat. I am planning on using a total of 4 overkill 120amp bms components per string (8 total). The Eve cells are 1C 280ah.

What’s the max continuous discharge current for one of these single 48 v strings?

What’s the max continuous discharge current if both 48v strings are switched together?

My max draw would be around 350 amps from the motor and rarely would be done.
 

sunshine_eggo

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I’m building 2 strings of 48v battery banks for a 20kw electric motor for a sailboat. I am planning on using a total of 4 overkill 120amp bms components per string (8 total). The Eve cells are 1C 280ah.

4X 120A per string sounds like you're stringing 12V together to make 48V, i.e., 4S2P

What’s the max continuous discharge current for one of these single 48 v strings?

120A

What’s the max continuous discharge current if both 48v strings are switched together?

120A * 2 theoretically, but likely a little less

My max draw would be around 350 amps from the motor and rarely would be done.

Likely a no-go.

16S Chargery BMS with a DCC200A contactor each would get you nearly 400A.
 

cobratom

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Jan 18, 2020
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I ordered two of these https://www.aliexpress.com/item/1005002997980729.html
for a 48V Polaris Ranger application where I know I will have a constant discharge of about 200A and peak discharge of 600A.
I will run 2 24V setups so one BMS per 24V side.
If I run into issues during testing that causes the BMS to cut out, I will do two banks of 48V wired in parallel.
 
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