AFAIK, it can only be done with the mobile app, i.e. via BT.
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So to turn on power you need to use your phone? Does that mean that the bluetooth module is always powered?
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I’m afraid that’s right. Not ideal.
Yes, but it’s in a low power mode when the mobile app is disconnected from it.
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And if I wired it to a rocker switch or similar, i wouldn’t be able to charge unless the switch was in the on position?
I don’t think you can wire it to a rocker switch. The BMS has to receive the command via the UART port to enable/disable discharge. It’s a bit like if you tried to replace your TV-set remote with a rocker switch.
Charging is irrelevant IMO. You can charge regardless of whether discharge is enabled/disabled. Here I assume that by “to turn on power” you actually meant “enable discharge”.
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I do mean to enable discharge, but it would be nice to have a way to turn it off completely to stop the bluetooth module from draining the battery… or is this not a real concern?
I don’t think it’s a concern. I don’t know how much the BT module consumes in the sleep mode but I assume it’s negligible. Otherwise that would be really stupid design.
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The bt modul will work as soon as the balance wires connected. To totally switch it off you would probably need to cut the power supply to the modul directly with a switch.
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The BT module has a blue LED, which goes on when the module is active and off when it’s in the sleep mode. You can notice that anytime you close the mobile app, the LED immediately goes off.
Adding a switch to cut off the power supply to the BT module as Andy is suggesting is of course possible and easy to do. I just don’t think it’s necessary. If I were you, I would start without it and only start worrying about if there’s noticeable battery drifting. Even then, I would double-check the BT module is the culprit since the BMS circuitry itself may be responsible for some drifting.
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@glyphiks I think there’s 2 pads labeled k1 next to the temp sensors. If you get the pc app I believe you can enable the switch and then wire a simple 2 pin switch too the k1 pads.
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I saw that in the documentation, but mine doesnt have those two pads… i got the 10s 20a version because I want to bypass discharge for the board, but I want to run a battery gauge off the discharge of the BMS…
Mine does have two P- pads at the top, but documentation says to leave those blank… what are they there for? 
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I’m not 100% sure. It may be able to do charge/discharge on both a single port or separate ports.
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And on the note of 2 pads… why is there 2 pads for b- and two for c-? Are they the same pads? Does it matter which I connect to? Goddamn BMSs are confusing 
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Why though? You could simply switch the wire leading to the battery gauge. You don’t need anti-spark switch for that.
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Because I want the battery gauge to turn off if the BMS cuts power. Silent alarm.
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I see. Maybe then have the discharge always enabled on the BMS and use a toggle switch on the discharge wire in addition to that?
Or just switch it on/off with the mobile app. I guess I would just do that if it’s only driving the battery gauge. I wouldn’t want to enable/disable discharge for VESCs in that way but for battery gauge… why not.
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That’s a great suggestion, I will have a play with it once I get it connected properly 
thanks for your help Jan 
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Check the pins next to the temp sensor wires. You have there 2 small solder point. There you can connect 2 wires to it with a switch.
And btw you can draw power from C- too. It is charge and discharge on one line.
Last thing: there are some faulty ones from a batch going on. When you order 10s and you have a the small balancing plug (not +15s plug). Check it balancing works fine. It is possible when balancing kicks in the bms voltage on group 1 or 2 start doing strange things. I have contact llt but never had any response.
Example off this:
Balancing on:
Balancing off:
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Ahh i see them now!
Right there for those of you playing at home.
Thanks Pjotr and @M.Hboards
Not entirely sure if I will use it now, but good to know that it is there.
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Ah, nice! I never noticed those. Good to know and sorry for the wrong info.
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