oh wait you guys are right, something is wonky here!
you wired it backwards?
1 Like
6 Likes
yeah I think I did wire it backwards. WTF it’s cause I usually solder my leads to the negative terminals but this time I did it to the positive and so I got everything all goofed up.
2 Likes
man I have no idead what the easiest way to fix this would be. Do I have to resolder all my leads?
Can you depin the connector and switch them round?
Some have a little plastic tab that you can pry up and then gently pull crimped wire out?
2 Likes
I’ve done this before, isn’t too hard if you have an exacto knife or a small flathead jewelers screwdriver
1 Like
I have just removed pins, not relocated them so suggest doing so with care. Maybe test on something else first?
1 Like
just for reference, incase it wasnt already obvious
so just switching around the wires should fix it? Also, regardless of the BMS being wired backwards, would the XT connectors read voltage even without the BMS plugged in if the rest of the stuff was all soldered properly with good connections? Because I’m not getting the pack voltage through those either
I think I need to switch my neg and pos leads around too since I wired the charger and loopkey and all looking at the terminals wrong too. Good lord I really botched this one up. Good thing I’m not a surgeon
2 Likes
using something non metallic to depin the connector
5 Likes
a resistor inside is blown, you will need to replace it, or just buy another one as they are dirt cheap
this happens to all bmss who have the balance wires connected in wrong order
3 Likes
Yeah I have an extra one. So depin and repin the connector and then swap the main neg and positive leads around. Does that sound right?
Here’s before the maddness and after for reference and analysis.
i think you got it totally wrong, the first “celll” is the positive end of the p group where the negative output wire comes from
as you can see here
1 Like
Are you sure? Can’t you solder your balance leads onto the positive terminals like I did and consider that your first cell?
Yup. It’s all kinds of backwards…
Suggest you test everything with your meter (with the correct probes on correct polarity) for all connectors before plugging in.
1 Like
well FML I think I’ll unpack everything and desolder all the leads, start fresh tomorrow. HAH I’m dumb
1 Like
Positive is same voltage as the next negative.
First lead to pack negative.
Then leads to each negative after that.
(Or to P1+ve, then all positives)
To test after complete; start with black probe on balance plug negative and test each point, voltages should rise sequentially across the plug.
2 Likes
You do not have to.
Positive is ok.
You just need to be able to measure voltage differential across each p group.
Negative is common but positive works also
2 Likes
for sure, and they do through the balance plug but just, well backwards polarity lol