Payment for help Battery won’t switch off (start at post 42)

So I built a 12s4p with the bestech 12s hcx-d596. Everything worked fine at first when I tuned it on. I noticed that the indicator was already reading 100. I plugged in the charger and the red lighting came on so I figured it was working. I turned it back on about 30 min later and now the indicator just flashes on and the right back off. If I plug the charger in it will show 100 percent on the indicator and not disappear instantly. It’s only when I I turn the power switch on and without it charging and then it just comes on then right back off. I tried changing infdicators and power switches Any advice would be greatly appreciated

Open it up - check everything. Balance wires, connections, look for marks on the BMS. If there’s nothing there - @barajabali can probably help with a diagnosis

I did. Everything is secure. It’s weird because as I connect the black wire from the indicator, the voltage between the xt90 leads drops from like 25 to two. If I plug in the charger during this time, the voltage shoots up and the indicator stays on. When it’s not plugged in the indicator shuts off.

When indicator is not plugged in the Multimeter read from positive to negative terminals on batter is 42. The voltage between B- and the red lead in xt-90 is 42. The voltage between P- and the red xt90 lead is only 25. If the charger is plugged in it will go back up to 42. If the charger isn’t plugged it, it reads 25 unless I connect the black wire of thenindicator and then it drops to like two.

Hmm when you connect the charger and measure is normal to show 42v because thats what the charger gives you.

What is your diagram ? where you connected the indicator ?

Maybe something is wrong with your indicatore or smth dont really know now. Try to remove it measure the battery voltage. Than connect the charger. If the charger turns tu red it means that is charging let it for 10-15 mins than remove it and measure the batteries.

Also are you sure you connected all the ballance wires is the proper order ? Please share some pics maybe ?

Show pics of your pack wiring

Also use a multimeter to see what voltage is going to the display and test if it drops to zero when off

Ok guys I really appreciate the help @Bloop @anorak234 and @barajabali . Here are pictures diagrams and a movie


YouTube video That does a better job at showing the issue

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Also can you measure your battery directly from battery wires not from bms ? Is your bms wires as here ??

That post was how I knew to wire how I did. If o touch just the negarive and positive battery terminals with no bms it reads 37 V. They’re obviously not fully charged so I don’t know why then indicator and charger were showing full when they were plugged in.

Alright so from what i understand the battery is fine with 37v ( not fully charged but not dmged as you said it showed 25v)

So the only thing that i can imagine is something wrong with the bms wireing. I cannot understand from the pics what each wire do. Also check the ballance wires again. measure one end of the battery with each ballance wire and see if they are all giving the right voltage

If I check the terminals of the batteries it’s 37. If I test the positive leed inside the xt90 and then hold the negative leed to the B- port on the BMS I still get 37 V. It’s only after switching to measuring the positive Xt90 leed vs the P- (instead of B-) port that s suddenly drops to 25. Since P- is also where the black indicator wire connects, it seems like there Must be some issue when passing between those two parts of the bms.

Yeah something is not ok with the bms. I had some problems when the ballance wires were not connected properly.

For start you should make it just get you 37v on P-. for this id remove the chargin id remove all other wires from the indicator and only keep B- and C- and the ballancing wires chech every and each of them. If you cannot get 37v from P- and ballancing wires are ok then maybe something is wrong with the bms and might be worth checking with lucy

Since the balance Leeds are 13 pin for a 12s I followed the balance diagram here just for a 12s instead of 10

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I already tried this. The p- with nothing on it is the point where it drops to 25

What do you mean ‘12s instead of 10’ ? is normal to have 13 pins for a 12s battery.

b0 is with the neggative battery wire and with B- b1 is for the first cell . . . b12 is the last cell

This diagram you added is exactly what you need to do

Your right for some reason at the last moment I thought I had put in a 10s diagram. That is exactly what I did

So the only things that’s abnormal about the pack is that it’s jist shutting back off immediately. When you test the leeds on a normal pack there is very little voltage until you turn it on then it shoots up to where it is supposed to be. So in my pack when I have it off it measures a low voltage and then when I turn it on the voltage shoots up for just a brief second then goes back down. Same with the indicator, it comes on for a brief second right when the voltage shoots up then right back off. I wired it exactly how in the diagram above. Can anyone help please?

You’ve verified all your balance wires being connected correctly and being connected to the Bms properly if so then i’d say something is fucked with your BMS. Also nice bag in your video there :stuck_out_tongue:

I’ve been thinking about this last night but the only thing i could imagine it being is a improperly wired balance wire or a fucked up BMS of course its hard to say without having the pack inhand but did/have you verified the voltage between all the balance wires before plugging in?

Yeah. I certainly appreciate you taking the time to give your input