ah yeah never mind so hahahaha
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Btw, what do you know about running 2 of these in series? (Theoretically both receive 25V at full battery)
Sounds like a recipe for an unstable regulator, unless there was something external to the BEC modules keeping the split at an even 25/25 like a resistor divider. I mocked up a circuit here, but basically where I’ve marked the two “25V” sections, the only thing balancing the split between the two are the input capacitors.
Caps with a proper and equal rating will theoretically evenly split a DC voltage, but
- Real caps are far from precise
- The voltage across a cap depends on the charge on it, and as the mosfet switches on and off it pulls charge out and allows it to recharge. The mosfet doesn’t usually switch at a dependable duty cycle because there’s logic trying to regulate an output voltage, so the two circuits would work against each other and (likely, imo) be very unstable
You cooould “balance” the charge externally by putting two equal resistors there alongside the caps, that I think would make it more stable, but still no bueno.
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you could run two in parallel, both would be exposed to the 50V input but would have half the output requirements. Given it goes up to 72V then 50 isn’t terrible, I’d personally recommend buying one decent one rather than many dodgy ones because if one failed it would heavily load down the others and you likely wouldn’t know until they all blew, but if the cheap ones are an 5x or more cheaper it’s a pretty valid choice to double or triple up. That doesn’t help when your initial question was about finding a decent one though 
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If your charger is sparking then it’s a shitty charger. The solution is a better charger.
edit: @BenjaminF is probably correct. Did you plug the charger into the board before you plugged it into the wall? Don’t do it that way.
I don’t have a dedicated charger yet, was planning on building one but still waffling between an XT60 or XT90 port on the charger. XT90 would match the existing hardware, but XT60 is cheaper and sized more appropriately, but also lacks the AS, which is what I wasn’t sure about. I’m 70% sure on having the BMS removable, so in theory the end wouldn’t matter regardless, but hey compatibility.
Sorry, I don’t have any recommendations. I build all the ones I use. 
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XT30 would be my pick
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XT60 is the smallest the manufacturer has without going to weirder ones like XLR and alligator clips, and I have a bunch of XT60s and 16AWG left over from other stuff and no XT30s so I think it’s the best option at the moment.
There’s an extensive list of converters in here:
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Be careful with that style. There’s a bunch of fakes on ebay/aliexpress etc.
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Then just change the connector 
Why dose this matter at AS is to stop the Inrush current from connecting things like capacitors why do you want this on a battry charger
Why do you want to use a 90A conector on I’m guessing a 5A charger. Is that not massive overkill
Would you want to plug you charger in to your loop key? I’m parity sure that would damage your charger. Surly a difrebt conector stoping you even trying would make more sense.
I went for this thing in the end
I don’t hope dhl can have it at my door by saturday from hong kong but there’s next week as well…
As for running multiple in parallel, in theory they all end up producing the same heat, just spread out over 3 pcb’s instead of one. Maybe i’ll end up making a wind tunnel under the battery box for them and try not to roll in mud like a pig from then on.
The decent ones are like £60 a piece and don’t look like they’re meant to be used by the average diy guy. Even found one at £412 with some fancy certifications
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That was answered earlier, the original question was whether it mattered or not.
That’s actually the point, the only thing that uses XT90 is the board, while my other batteries use smaller connectors like XT60. Plugging a charger straight into the board is unlikely to damage anything if the battery is already balanced, while plugging any of my other batteries into the charger would blow them up immediately due to massive overvoltage and overcurrent. Having XT90 makes it inherently incompatible with any of my smaller batteries.
Either way if it goes according to plan the charger should never be disconnected from the BMS in the first place, so it shouldn’t actually matter what connector is used. Could be soldered on for all I care, but modularity is nice.
Fairly certain i have the “real deal”, just that the lacroix lights are really noisy and consume 2A total. That thing commits suicide in 10 minutes at half an amp with no heatsink
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The efficiency vs output curves for these things can be pretty wild so logically that makes sense but in reality 2x BECs running in parallel close to their efficiency peaks can generate much less total heat than one heavily loadrd one plus:
If there’s double the surface area you get significantly lower temps at each one to expel the same amount of heat (it’s not linear because heat transfer is a logarithmic function of temp), but I’m actually not sure how relevant that is in a closed(ish) system like an enclosure. The limit is likely going to be the trapped air to atmotpshere junction rather than the heatsink to air junction, maybe someone else can clarify that. It’s mentioned in the video I linked above that those BECs are often designed for RC planes with a LOT of airflow so some will just be unsuitable outside of tiny current draws
Sounds good. @Boardnamics can you confirm? With the Evolve pulley on TB 110 wheel it’s about 13mm from the pulley-facing surface of the wheel bearing to the seat of the pulley bearing. Since a bearing is about 6mm wide the evolve pulley takes up about 20mm of axle length.
Does a Boardnamics pulley take up less length?
I have one of those on hand. Kind of tricky measuring it but your numbers sound right.
My kegel pulleys take up a spacer (5mm length) and a bearing (7mm length). Certainly less than that pulley.
Also for what it’s worth, mine spin more concentric and will last longer 
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Can you identify a noise from this non descript video?
Been trying to locate this rattle, everything inside the enclose is either secured with velco, battery has silicone underneath and on the sides, all cables secured and not free to move, I can take the enclosure off, turn it upside and shake it and nothing goes anywhere, any idea what could be making this noise?
On the smooth road it’s silent, over cracks or on rough street it makes the noise
Enclosure has a rubber gasket and is tightened down, don’t think it can be the truck bushings or washers?