Bot

@James Brannan petty Good i also recommended

@@michellegoodman5109 right

He does; it's called DIY Perks and it's on KZfaq. =)

Hi there, I am working on a 18v battery protection circuit. A gerber file for a PCB would work great. Could you please share a link/file to the gerber file and a BOM? What circuit did you protect? I really appreciate it!.

***** I'll try that next time. Thanks for the tip!

+DIY Perks With a steel straightedge. If you angle the blade a little different each pass you can get a little curl to come out of your cut. Then lay a piece of sandpaper on your bench and rub your cut end on that a little. You get a nice clean straight edge. Polished even.

Filip Babic thanks

ATS : Automatic Transfer Switch

Cool if u find one please do comment about it here

wow, 3 years 0 replies from anyone, ill try chip in i have a recommendation for you, go check out a dude called great scott (kzfaq.info) it is kinda hardcore electronics, but he does explanation videos of SO MANY THINGS!! he also has absolutely great battery protection circuits that he designed from scratch (kinda) in his videos they are for Li-ion rather than Li-Po, but its the same theory he also has videos of what goes wrong if you intentionally over-discharge and short circuit and things like that very good for education :)

But this being a discharger, you shouldn't be walking away from it anyways and should be disconnecting it as soon as it's done.

@@pontiacdriver999 This isn't a discharge load, this is a discharge protection circuit. This cuts the connection when the battery is discharged.

That should be fine, you need a balance charger to recharge the battery anyways.

Any suggestion of how to improve the design?

+Power Max That sounds interesting, as last night my LiPo buzzer drained two of the 4S cells. Might you be willing to draw a schematics for your solution? Would be greatly appreciated!

+iemandsanders Darn, that sucks! That's why I don't trust those things. Mine isn't even accurate! But to make my analog low voltage cutoff, a simple latching circuit is what is needed. You _could_ just use a comparator, pass transistor, and a voltage reference, but this will continuously draw milliwatts of power for the comparator, and comparators can be physically large too, at least compared to transistors. I did not have any final schematics in-mind, but here is something that I threw together in LTspice to do this. I posted the ".asc" text file "read more" section, you will need to copy the data into notepad and save it as an .asc file, and install LTspice simulator to open it. It is based off of one of the simplest latching circuits I know of, using a P-channel MOSFET and a transistor. The cool thing about this one is that it draws ZERO (or as close as possible to it) current once the voltage gets too low. A zener diode is used as a reference voltage. When the circuit is initially activated, allowing something to be powered, and if the voltage across the zener diode is higher than its rated voltage, then current will flow through it and keep the base of the transistor saturated, thus keeping the MOSFET base pulled low and keeping the MOSFET activated. In this state, the circuit is latched and will stay latched until the voltage across the zener diode and R1 gets too low for enough base current. (In simulation, the circuit tends to latch automatically with an initial power connection. If this circuit does not latch automatically in real life, add a small capacitor between the base of the transistor and the positive of the battery) Because the zener diode and resistor is between the output of the pass transistor, and the input of the base of the transistor, when the voltage falls below that threshold voltage, the zener stops conducting, causing the base current to fall to zero, and the MOSFET turns off, then it will stay that way until the voltage goes back high enough and if the latch is reset by temporarily connecting a some resistance (around 10 kohms) between the base of the transistor and the positive of the battery. None of the values or components used in the circuit are too critical, I picked them arbitrarily. Version 4 SHEET 1 880 680 WIRE -48 -96 -416 -96 WIRE 80 -96 -48 -96 WIRE 272 -96 176 -96 WIRE 400 -96 272 -96 WIRE 608 -96 400 -96 WIRE -48 -48 -48 -96 WIRE 272 -48 272 -96 WIRE 272 80 272 16 WIRE -48 112 -48 32 WIRE 96 112 96 -48 WIRE 96 112 -48 112 WIRE 400 144 400 -96 WIRE 608 144 608 -96 WIRE -416 176 -416 -96 WIRE 96 208 96 112 WIRE 272 256 272 160 WIRE 272 256 160 256 WIRE -416 480 -416 256 WIRE 96 480 96 304 WIRE 96 480 -416 480 WIRE 400 480 400 208 WIRE 400 480 96 480 WIRE 608 480 608 224 WIRE 608 480 400 480 WIRE 96 528 96 480 FLAG 96 528 0 SYMBOL pmos 176 -48 M270 SYMATTR InstName M1 SYMATTR Value IRF9640 SYMBOL voltage -416 160 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName battery SYMATTR Value PWL(0 12.6 50 0 100 12.6) SYMBOL res 592 128 R0 SYMATTR InstName R_load SYMATTR Value 5 SYMBOL npn2 160 208 M0 SYMATTR InstName Q1 SYMATTR Value 2N2222 SYMBOL res -64 -64 R0 SYMATTR InstName R2 SYMATTR Value 10mega SYMBOL zener 288 16 R180 WINDOW 0 30 57 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D1 SYMATTR Value BZX84C10L SYMATTR Description Diode SYMATTR Type diode SYMBOL res 256 64 R0 SYMATTR InstName R4 SYMATTR Value 20k SYMBOL cap 384 144 R0 SYMATTR InstName FilterCap SYMATTR Value 100µ SYMATTR SpiceLine Rser=0.5 TEXT -370 518 Left 2 !.tran 100 startup uic

+Power Max Thanks! Will look into this asap, but sounds a bit tricky for me as a electronics novice :)

+Power Max Hi I am having trouble importing your text above into LTspice. Anyway you could post a quick picture of your schematic? This would help me out a lot!

+Chris Johnson Not on youtube I cant :(

I don’t think they have to be protected as they are like car batteries, although I don’t really know as I’m not an expert

Alberto Martinsen I usually use After Effects for any special visual sections :)

OK, thanks! It looks awesome! Congratulations again for your videos! Really looking forward for the next! :). And regards from Norway!

jorenmartijn Insulation and proper connections are the key in DIY projects. I tend to be careful with that stuff too so if your worried as i am, then superglue some plastic between the leads and as extra you can put some rubber glue over the leads+ the rails. I also recommend stuffing all that inside project box securely, even if it goes inside another project box with the battery. Added safety note would be to add plexy glass side of the box and quick opening system(if you want to save the circuit system that is), so if your battery starts to swell, you can see it, quickly open the box and trow the battery on the non flamable surface. Usually lipo battery dont explode, but its like mini flametrower. First signs of imminent battery failure is the swelling and heat, what fallows smoke witch is the point of no return what gives you seconds to react, before possible flames, so keep your eyes in the swelling and everything so it can be rapidly removed. Hope this helps! :)

Hellsong89, thanks for the explanation!

That would definatly be a problem if they were from battery + and -, however since if they short the worst thing is you've bypassed the relay it's fine.

I know this is 2 years old but What I do is use connectors. Solder connectors and test that non of them have any resistance to the other side and just connect them afterwards :) the only times I have to touch batteries basically is when changing their socket