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Acceptable DIY 6S3P BMS and battery setup?


#1

Hey guys, so I am planning to make a 6S3P battery and BMS pack but was wondering if any battery wiz out there could verify the setup with me so that I don’t blow myself up trying to make the pack, or much less ruin expensive electronic equipment. I have attached the diagram in this post. Any help would be very much appreciated!


Is my 6s 3p BMS wiring sheme correct?
How many batteries do i need?
#2

I’m assuming this is the BMS schema:

Your drawing is perfect. B- connects to the BMS via mains and the other wires via balance wires. Make sure you get a 6-pin JST-XH connector (those are meant for 5S) and not one made for 6S batteries.


#3

Seem Legit :sunglasses: But don’t forget to put a fuses before your switch, so in case of a problem you won’t burn your esc.


#4

@rubz yeah I basically followed that diagram but just added the cells in parallel

@JohnnyMeduse thanks for the heads up. Do you know if it matters where I put the fuse? as in which polarity to put the in-line fuse on?

Also, does it matter what polarity I put the 2-12S toggle switch on? I’ve heard that it is best to put it on the positive side of the circuit but there hasn’t been any proof why that is.


#5

I think this is better on your positive side, because the battery is directly connect to all your electronics, on the negative side de BMS should act as a buffer for the current (good BMS are suppose to protect your circuit). And for the switch it really depend on the BMS you use.


#6

so I’ve finished making the battery pack and wired the 2-14S toggle switch from Dexter, as shown in the picture. But now I run into a bit of a problem when trying to connect the voltmeter. When the voltmeter is wired (pos to pos; neg. to neg.), the reading shows a constant 100% no matter the battery state…even when it is drawing amps out of the pack. Does anyone know what I am doing wrong? Does it need be wired directly to the BMS instead of from the toggle switch?

thanks in advance


#7

You would wire it between the switch and the ESC.


#8

hm I tried that but the reading just stayed at a constant 100%. I measured the pack’s voltage and its at 21.8 which is nowhere near its capacity for 6S if I’m not mistaken


#9

That is near 6S. Did you have the power switch on when it was %100?


#10

Can you show me a picture of the voltage meter itself?


#11

I bet the voltmeter is configured on the wrong S count


#12




#13

pressing that little button on the back of the voltmeter also did nothing…soo not sure what the problem is here


#14

Have you ever configured the voltmeter? You should be able to scroll through the S count with the button. Check the instructions that came with it, or try holding or double tapping the button. It might be on a default 3s setting or something.


#15

it never came with any instructions…bought it somewhat cheap from ebay lol. but yea I tried pressing the buttons a couple times but I haven’t tried holding or double tapping it so i’ll give that a try.


#16

press it and hold, then turn on the meter. press the button again to switch types


#17

it worked! Thanks so much @link5505!!!