The battery builders club

[Crate]

@MysticalDork

The other test would be to plug the charger (turned on) into the socket, and then probe the back of the socket to see which of the pins are positive and negative. For that you would set the multimeter to DC volts mode.

Took me a second to understand this. I did it and with the probes on my wiring setup i get negative readings. I finally got a normal positive reading when i put the black probe on the empty DC prong(shown in pic) and the other on my red wiring.

So my wiring for negative is wrong?

[MysticalDork]

@Crate

So my wiring for negative is wrong?

Possibly.

[Crate]

i dont understand, i probed the port the same as i did in the first video and now i get no beeping. Only beeping when i put black on the empty prong

[MysticalDork]

Are the wires connected to anything? They should not be during testing, it can throw off the readings.

[Crate]

No, same as it was in that video

[MysticalDork]

In the video I can’t see the other ends of the wires.

[Crate]

It was connected to nothing in the video.

What does the beeping mean, am i not supposed to hear a beep when i touch my pos/neg wires ? Im doing all this checking and have no clue what this means if its good or bad

[Crate]

ok nevermind i got it beeping again when touching my pos/neg. still dont know what any of it means

[MysticalDork]

@Crate

still dont know what any of it means

Beep means a short circuit between the two probes, through whatever they are touching. A beep between positive and negative is BAD. A beep between the positive wire on your charger, and the positive wire on your charge port, is good. A beep between the positive wire of your charger and the negative of the charge port would be bad because that means it’s wired backwards.

You need to plug a connector into the port, and measure continuity from one of the plug wires to one of the port wires, to figure out which goes to which.

[Crate]

@MysticalDork

Now plug in a 5.5mm jack (a bare one) and probe it again. It’ll be different thanks to that switched contact.

Did this, got no beep.

heres a better picture of when i plugged the CP into the charger input

@MysticalDork

You need to plug a connector into the port, and measure continuity from one of the plug wires to one of the port wires, to figure out which goes to which.

Why is there no beep when touching both the bullet connectors, but when i touch the 2 charge ports prongs i get a beep?

Could you tell which one is positive and negative from this video? Streamable

[MysticalDork]

One of your connections is definitely wrong, I can tell that because you should have no beep when measuring between black and red, and you do have a beep. That means one of those two connections is wrong, and should be on the terminal that is currently empty. Unfortunately I can’t tell you which of the two is wrong without more information, only that one of the two needs to go to the other terminal.

Here is what I recommend:

• Unsolder both wires from the charge port.
• Plug your charger into the charge port, and power it on.
• Use your multimeter set to DC volts to find the two connections that give the correct voltage reading, AND the correct polarity.
• Re-solder your wires according to your findings.
• Double-check the ends of your wires again with the charger attached to make sure that the red one is positive and the black one is negative
• Unplug the charger from the charge port and check continuity between the red and black wires to make sure there is no beep between them.

[Common_good]

@MysticalDork

Long power wires

How long are we talking b4 it starts throwing faults?

[Battery_Mooch]

@Common_good

How long are we talking b4 it starts throwing faults?

There’s no set length that can be used for every setup.
In addition to the power lead length it depends on the particular ESC (and its component voltage ratings), your pack voltage, and how the cables are run.

All we have are the “best practices” @MysticalDork mentioned, resulting in the standard “the shorter, the better” recommendation. It’s all we can do since we can’t know how close each setup is to causing faults or damaging the ESC.

[zero_ads]

Cut and resolder

[vegr0]

I just reverse my end bullets and leave the JST wire alone?

[zero_ads]

Yeah I think that would be easiest

[vegr0]

I need this JST to connect to the my BMS. I assume that’s what these 2 extra holes are for?

[zero_ads]

I can’t speak to what you need to do in order to get it to work with your Eovan. But those two extra holes have to do with just the negative side. The B- is meant to go to the battery negative, and the C- is for charger negative. So if that applies to your application then sure

However why do you need this JST connector? To charge your battery? Is there no way to bypass it?

[Crate]

thanks

I followed all your steps, found the correct negative/positive DC, and resoldered. Checked again when hooked up to a charger for correct DC volts and no beep.

only got a beep when i touched the other pin.

[vegr0]

Lol first time im seeing this image now…good thing i wired everything right. So the c- and b- holes are literally both the same?(not interchangeable - i mean both ports on the same side act as one) At first, i questioned which one i needed to wire to but i referred to a bms YT video

Even though this battery is too thick to close the lid i at least want to plug it up to the electronics and give it a spin, and also want to give it a small charge to confirm everything works

In the last image i uploaded, you can see the other end of the JST that goes directly to the charge port inside the board.i was going to open the existing battery pack to confirm that’s how it’s wired but didn’t after I realize there’s no other way it can be wired up(right?), and their choice of connector was a JST.