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
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.
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.
I guess we’re all ghost busters now….
Or only this particular one in my experience
And there is a 16-20s version of it
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
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.
how much idle drain is normal?
v1 micro USB ubox
voltage as of 03/16:
voltage as of 04/19:
seems tame enough. also have lights connected
Seems about right, I topped off my 12S4P pack with a LLT/Ubox v1 once this winter, went from 3.7v to 3.4v over ~4 months…
The bigger 12S10P on a newer LLT/Ubox v2 sees no significant change whatsoever… but at 2.5x the capacity i’m not too worried.
Would like to see some hard data on the Spintend ESC.
I’ll add another anecdote to the mix. I’ve built about a dozen boards, none have had passive drain like the Ubox board I built. One of the boards I built last year had a first gen Ubox in it + 12s4p VTC5a. The rider who was using it reported that the board was rapidly loosing charge while sitting idle for a few days. 100% to 60% over a weekend for instance.
My initial assumption was the cells due to their age and origin (old batteryclearinghouse stock), or bms failure. Although I replaced the battery and the Ubox with a Stormcore, I haven’t seen drain on original battery after removing it/ disconnecting the Ubox. No other issues with the Ubox besides that though.
*I have two OG Uboxes and two 12s4p batteries laying around maybe I’ll do some isolated tests.
Cough…
Nice, so you could leave our board at only 25% charged for over a year. I would expect it would be alot worse then that so that was nice to know. The drain people have got on XLR was not related to the esc. If you believe it could drain a 20s8p that has not even been out in 1 year yet I don’t know what to say. The drain on XLR was the external buck converter. This you tagged me in does not change anything I stated before, it did actually prove what I said.
I never once said anything to do with your board did I? You came in aggressively stating that I don’t know what I am talking about. All I said is the Ubox is well known to drain batteries
Then I gave some anecdotal evidence about how we have experienced the same problem
Then you came in (because you sell Ubox and didn’t like what I was saying) and said
Which, is wrong. In fact as you can see from @jaykup testing the Ubox 75V V2 is significantly worse than say the stormcore 60D, or most other ESC - by a massive amount.
And then you said
Which really pissed me off, because I said nothing about your ESC, your boards or your brand but you jumped in anyway with this statement and now we can all see that it is fact you that has no idea about it.
Also, he said that higher voltages cause more drain. If the 100v ubox is similar in parasitic drain at 48v, the drain at 84v will be massive
I think it would drain a little faster than that. I had a mix of uA, mA and some conversions in the cells which isn’t obvious so the math might not be that clear. Plus the draw increases as voltage increases.
Here is the detailed math:
Ubox 75v V1
16s * 6p = 96 cells
96 * 14.9wh (capacity @ 200mA drain) = 1430Wh
Assuming 16s @ 4v = 64v. This is in the middle of the 60v and 70v numbers, so call it 4mA
64v * 0.004A = 0.256W
1430Wh / 0.256W = 5,586 hours / 24 = 232 days.
At 25% charge, that’s 58 days.
Ubox 75v V2
16s * 6p = 96 cells
96 * 14.9wh = 1430Wh
Assuming 16s @ 4v = 64v. This is in the middle of the 60v and 70v numbers, so call it 2.2mA
64v * 0.0022A = 0.141W
1430Wh / 0.141W = 10142 hours / 24 = 423 days.
At 25% charge, that’s 105 days.
I did not even tag you or said anything against you. I just said many likes to flame without know anything about what they flame. I did not even mention “our” esc. I just said something about ubox100. So I don’t know why you think I’m aggressive against you.
