Noob question thread! 2020_Summer

Can’t remember firmware. I’ll check it out. I switched over from a Maker X DV6 to Torque6 ESC and that’s when the problems started. Maybe the Torque6 has slightly different version.

I’ll run it sensored and see if I get the same issues. Cheers

It’s not a hardware problem, it’s all software.

1 Like

What’s the solution to get telemetry on a dual setup without can bus, if the 2 esc are just in split PPM ?

You just have to multiply certain numbers by two as a guess. CANBUS is much better for telemetry.

can a board be run until flat or what’s a safe way to preserve my lipos?

Set high cutoffs if you don’t want to puff them

1 Like

What prevents a spark when you plug in a charger? Is an antispark necessary, or can I simply use a standard XT60 or something as the plug?

Xt90-s has a resistor, so when you plug it in slowly the first thing that makes contact is the resistor, which slowly saturates the other side of the connection, preventing a spark. This is what is used for a l00p key

1 Like

That’s important when turning a board on and energizing it, but aren’t most chargers just simple barrel jacks? Those don’t have any form of resistor on them.

Oh didn’t see the charger part. The spark is caused by a difference in voltage. If the charger is plugged in, the voltage difference is smaller (let’s say a maximum of 9 volts on 10s between a 42v charger and a battery at 33v).

Right, but is that spark a problem? I don’t usually see people doing anything with them, but I’ve also seen plenty of blackened charge ports as well.

If the voltages are similar there shouldn’t be a spark. I forgot to say this in the last message. If the charger is plugged in there shouldn’t be a spark

1 Like

@Evwan this statement is kinda true but doesn’t tell the whole story.

@frankthedragon the spark when plugging the ESC into the battery is caused by “in-rush current.” The ESC has a large bank of capacitors that, when connecting them to power, want to fill up to full capacity ASAP (think milliseconds). That massive rush of current happens in the millisecond that the connector makes contact, and since there is momentarily a massive rush of current going through an extremely small surface area on your connector, it sparks.

As Evan explained, an XT90S connector has a resistor built into it that limits the in-rush current, forcing the capacitors to charge more slowly, so no spark happens.

Now to tie it back to your original question about charge ports. Your charger also has capacitors inside of it (at least, most of our chargers do). If your charger is un-plugged from the wall and you plug it into your board, you will in fact get a spark at the charge port on your board. It’s the exact same phenomenon of in-rush current, basically the capacitors in your charger sucking a massive amount of current from your board’s battery for a moment until they are full.

The reason that we dont need an XT90S or any other type of antispark charge port is because you can easily mitigate the risk of sparking by simply plugging your charger into the wall before plugging it into your board. This allows the charger to fill it’s own capacitors from the wall power, rather than from your battery. Then when you plug it into your board, there should be no spark.

8 Likes

Hey there! I just upgraded my board to a 12s, and I only have a 10s charger at the moment, the 12s is coming sometime later this week. I is it safe to charge with the 10s charger? It has a Bestech BMS in it as well. I figured it wont get to full charge but I want to be safe it wont hurt anything.

It’s only gonna charge it to 42v if the BMS even accepts the voltage. 42v is close to dead. There’s no point I’d recommend buying the right charger and just wait.

4 Likes

When chargers are in action their voltage “moves” to match the pack voltage, so a 12S charger is only at 50.4V when it’s basically not charging. You can see this in action by sticking a multimeter across the discharge port while charging and watching the voltage creep up to the full voltage.

With that in mind, I’m fairly sure no BMS is gonna care if your charger voltage is below 50.4 (because it’s supposed to be most of the time) as long as it’s not so low that current flows out of the battery into the charger. Open to corrections though

Anyone know why battery resellers add these kinds of extra stickers to their cell? Is it for ease of knowing what cell it is when sorting them or something?

1 Like

I’ve heard it’s for shipping/customs purposes, but dont quote me on that.

@Battery_Mooch probably knows.

1 Like

Have a look here it has a really good database of most cells, hope it’s not but whenever I see a sticker like that i expect the worst.
Never not found a cell there

2 Likes

Yeah that was my initial expectation too, but I peeled back the sticker on one of them and it appears to be the cell I ordered (and I’ll probably peel them all off when I make my pack) . I think @BenjaminF might be right on this one.

I ordered from bulk battery, which from what I’ve read is a reputable seller so Im not expecting any surprises here :sweat_smile: (hopefully)