The battery builders club

How-Tos & Esk8 mechanics
, , , ,
#12107

Do you have passive balancing enabled in the BMS settings?

1 Like
#12108

Idk but Iā€™ll go check

#12109

Unless @Skyart enabled it when he sold me the pack, no because I didnā€™t pay $6 to write BMS configs. It looks like it is on though because it says next to each P group voltage that itā€™s balancing

#12110

That word [BALANCING] will light up when it is actually balancing. None of the cells in those screenshots are currently balancing. Which leads me to believe that passive balancing is not on, so there is some other reason why your Cell1 is self-discharging.

To answer your original question, 0.1v of imbalance is not unsafe or crazy by any means. The fact that your Cell1 is self-discharging though, could indicate a problem.

Most likely though, itā€™s the BMS which is discharging that cell.

1 Like
#12111

Gotcha. I had just plugged in a metr and used it and set it up without motors plugged in before I took that recent screenshot, and before that I really hadnā€™t used it. Is there anything that you recommend I do to prevent that P group from discharging?

#12112

Unplug the balance harness from the BMS. That will totally power it down

1 Like
#12113

Will do! Artem siliconed it into the port so I gotta cut that away lmao but thank you for the help!

1 Like
#12114

What the fluf?! How did that pack get so out of balance?

1 Like
#12115

Yo thatā€™s kinda susā€¦does anyone know if thatā€™s the cell that the BMS runs itā€™s processors and BT module off of?

1 Like
#12116

Dude honestly idk I havenā€™t touched it since you sent it to me because it was the first part I bought

#12117

Should I unplug the BMS and just let it sit?

#12118

I would have to assume cell 1 because all the other cells are balancing roughly the same

#12119

I personally would leave the BMS connected unless you are putting the battery in storage

1 Like
#12120

Iā€™m gonna have this build up and running by hopefully this Wednesday but at the latest this weekend, just waiting on the last of the parts to show up in the mail. Iā€™ll leave the BMS connected and just hope for the best and keep an eye on that cell as I charge/discharge it?

#12121

I should send you my carbon gt then to look at haha

1 Like
#12122

Question, would a Daly charge only bms have any discharge while in storage? Is this only an issue with smart bmsā€™s?

1 Like
#12123

I would think yes but to a far lesser degree, the LTT BMS has a Bluetooth module that is constantly pinging out into the void and using power while the DALY only has a over current and under voltage monitoring system running. In theory leaving any battery with a BMS for long enough will drain it until the battery is irreparably damaged, but that would take months to years to happen. You can mitigate the quiescent power draw by unplugging the Bluetooth module from the BMS and the balance leads but the cells may still leak power after a certain amount of use (damage occurs constantly in a cell, especially at extreme voltages or high currents, so after a while the microstructures in the cell can cause microscopic short circuits and dissipate as heat)

4 Likes
#12124

Good stuff, thanks for the knowledge!

1 Like
#12125

Uhhā€¦no. The longer you donā€™t look at it the longer it will be before its a problem, the count down starts the moment you acknowledge the problem

#12126

I ride it it periodically and check voltage. Probably due to check each P pack voltage.

Was more a joke comment.

2 Likes