Momentary switches only remain in the on position while being held down, where as latching switches ‘latch’ on, and or off when actuated.
If the two wires are connected, the BMS will always be on. At least, I think so. It could be the other way around, though. I’m about to hook one up, and I can let you know.
edit: It probably is reversed. I doubt they’d build some sort of sensor into the port that detected whether or not a switch was connected, and so it’s likely always on until the circuit is completed. Which kind of bums me out since I didn’t order a button that functions like that. I wonder what a switch like that is even called.
Hmm, it might be called a ‘push-to-break’ or ‘normally closed’ latching switch, aka SPST normally closed, latching switch.
edit #2: holyshit this is confusing.
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You might be right. It might actually take a momentary switch. That may be all it takes to cycle.
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I haven’t hooked it up yet. Is there a way to tell when it’s “on”? Does it have an LED or something?
The plan for my setup is to bypass it for discharging so it would help if there’s way to keep it powered off all the time, except when connecting the charger.
Don’t they have some sort of manual or instructions for these models? Their website is quite confusing and they have so many variations of these BMSes
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I’m digging through their website right now trying to figure it out. The documentation I see only relates to their older BMS’s without a on/off function.
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Just don’t plug in the switch and in Bluetooth settings turn off “Switch Function”
But wouldn’t it always be on in that case?
Yes, why would you want to turn off charging or telemetry?
Storage. I would only turn mine on to check voltages, and to charge, as I don’t expect p-groups to need balanced.
That’s my idea as well. No need to have the BMS powered on 100% of the time. Even if minimal, it will still drain the pack slowly.
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The receiver on mine flashes iirc
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Half stuck together. It’s not pretty but feels solid and more importantly fits in the box.
I know, I know, it’s clear hot glue. Not ideal, I didn’t buy the black stuff I see everyone using.
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2nd half is glued together, we’re almost ready to start welding
Here’s what I’m considering doing. I could make it a sort of “multipurpose” pack. I’m thinking about making it so I can use it as two separate 6S packs. I already have 6S JST male and female connectors.
The reason is that when I wouldn’t use the board, I’d be able to use the 6S packs for a different hobby where… I need 6S packs. This would also allow me to charge them individually with my balance charger (which tops out at 10S, so couldn’t use it for the full pack). Another advantage is I’d have a backup way to charge it if the LTT BMS dies…
Does this sound too crazy?
Not the prettiest welds but I think they’ll hold. Taking this part slowly, I really don’t want to short anything…
If it all goes well, maybe we’ll finish up the pack tomorrow. 2nd cell section, wrap and leads are still left to do.
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This is not going to win any beauty contests, that’s for sure.
At least we have a few lessons learnt:
- I’ve bought fish paper way too thick. Not being self adhesive is also a pain. Not much to do about this, it was the only kind they had at the store and I didn’t know what to expect.
- I don’t have large shrink wrap, it would’ve been nice and make it more tidy.
- in hindsight, I would’ve been better off designing a more simple and “square” case so I could have0 made the pack like a proper brick and not a weird shape like this one.
I welded extra tabs for the balance leads, everything will be on the top, I don’t have room for wires on the sides, where the welds are. Even on the top I don’t have that much room, I wanted to leave some space for foam tape to insulate the pack from vibrations… might get too tight.
This is how I ended up connecting the main leads. Should be enough, I won’t pull more than let’s say 40A total. It’s 0.15x8mm nickel strip (the welder can’t handle more than this). I soldered the strips first to the wires, cleaned them up and welded them over the existing strip which connects the parallel cells.
If anything here looks completely wrong, please stop me.
I know, I could’ve found a way to not cross the balance leads, but I wanted to stick to my initial plan of two individual 6S packs making up the 12S. This way I’ll have two 6S balance leads.
We might run into a bit of space issue, I might have designed the box a bit too tight, I hadn’t considered that I need to route wires on top of the cells. We’ll burn that bridge later…
All connections are good, voltage reads are as expected.
Yes, I intentionally left the balance lead so short, it’ll make sense once it’s all in the enclosure.
I just tried that BMS power switch, and for me, it does absolutely nothing. The BMS is always on regardless of whether or not those red/black power wires are shorted. That’s a bit disappointing. I might email LLT and see what they say.
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Strange. I ran across a random pic around here yesterday and it showed an LTT BMS with a switch connected to that port, I assumed it works as intended.
Is there any setting to enable the switch? I haven’t powered on mine yet. Maybe later tonight, I’m working on the pack as we speak.
I’ll dig around in the settings some more.