I’ll try that next week, there’s a Ubox sitting in a dead board I have to tear open.
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It’s not draining fast enough that I’m concerned about it, just faster than I would expect from self discharging. I use it for a 48v, 3kw inverter when the power goes out, and I just keep it at 46v. I’ll have to monitor it more closely to produce any figures.
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The problem is your BMS
This particular model has a higher then normal idle drain aswell. I would replace the BMS
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Ahh, thought you were using it in an esk8. Yeah, disregard what I said above.
@Skyart has seen more LLTs than most/any of us - time to pick up a different LLT or another brand of BMS.
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I’m also hearing from someone that in the Kaly XLR there is a buck converter direct from battery powering the servos for the stability control system. and that they tested this and think it’s the source of the vampire drain.
If someone could verify those tests, with some current numbers, that’d be nice to know.
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are some LLT better than others?
or you’re saying all LLT bms have higher draw than other brands?
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Surely Ernesto put this buck converter after the BMS so that it wouldn’t kill the pack, surely…
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The buck converter is on the discharge output of the bms
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So either the low voltage cut off failed or something else is draining the pack
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Is the buck converter in the Kaly always on?
The lacroix sentinel board only powers on the buck converter when it detects 5v (or 3v?) from the stormcore UART port.
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Yeah my only experience using the discharge on the LLT is with an actual physical switch.
If you leave the physical switch ON, everything stays powered and WILL drain the battery. Pretty shitty implementation there, so i guess it’s possible that it’s implemented poorly across the board
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I guess so, there is no remote/5v switch like a lot of better buck converters
I’d guess that the idle drain on Kaly boards is related to the buck being always on (and possibly stabilization servos or whatever else is connected to it).
I can only speak from my experience with 12s and 18s LLT BMSs. Mine are always findable on bluetooth, and the power draw has no noticeable impact on battery voltage if I leave my board idle for a week or a month. I like to leave my boards around 3.6 to 3.7 and I’ve never seen them dip in a way that would make me worried.
I feel so bad for the people whose houses caught fire. It’s a good reminder that an improperly built or abused board/battery system is a time bomb.
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Yeah i didn’t have the time/motivation/equipment to properly measure/test the xlr that I had here, but in my opinion it’s not the draw from the bms.
I’ve monitored the exact bms that’s in the xlr attached to a battery for nearly a year sitting idle and there was no significant drain.
The bms MAY be involved if the low voltage protection isn’t working properly, but in all honesty, I think the Spintend is to blame here.
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I guess we’re all ghost busters now….
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Or only this particular one in my experience
And there is a 16-20s version of it
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yeah somehow they get well below any bms cutoff. At least Mario Chacon’s XLR got to around 2v total.
is it a healthy ubox? might not be a great comparison if not 
ive got a factory refurbed ubox I could send you for testing if you like, supposed to be fully functional according to spintend. won’t have a use case for it for quite some time so lmk
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I agree, I currently have the 18s version of this bms hooked up to a demo unit and the idle draw is significant.
It does have a switch, (yet to hook up), so I can power the unit down completely
And to be clear, I have monitored the draw when only the bms is hooked up, as I am yet to complete this demo build.
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