Can I do a makeshift discharge test with a convoy S2+? Just curious if I can before I go for a hobby charger. I don’t need 100% accurate numbers just approximation to test some laptop pulls.
Got an old one that’s 7135 based? Yeh. I’d only try it with a wimpier light, like 3×7135 for ~1A draw. Otherwise the light could overcook itself if left in free air and uncooled.
Has anyone posted a summary of emitter characteristics somewhere?
voltage, lumens per watt, max current, availability, cri, tint, etc? So many new emitters since the last time I was hanging around here, and I don’t have a feel for what to use for some mods I’m planning.
A $25 Liitokala Lii500 charger is well known for it ability to do capacity tests. It can discharge and recharge a cell and it’s results are good. That’s the cheapest I know of.
I’ll have to check on that been a while since I took inventory. Thanks!
Yeah I was looking at that as well. Sad that the UC4 hasn’t come out yet. I was hoping not to buy more chargers except the UC4. Thanks for the recommendation!
If the resistor that limits current and controls brightness of the led is on the same pcb that the led is on, you can wire a battery to the tail cap and measure current inline to see what the draw is.
If the current limiting resistor is on the driver board then it’s more tricky. Here is a basic drawing showing a flashlight circuit.
If you were to unsolder the red wire from the mcpcb you could then measure the current from the red wire to the flashlight body. This should measure everything between those two points minus the led and driver circuitry, but should include any resistors from the driver spring to ground, like shown below.
I have not actually tried it to see if I can measure tail cap led draw, though. It might work, but it can be a pain unsoldering the wire from the mcpcb.
You can pretty much assume any type of small colored LED is going to be a fairly High parasitic drain. So if you have a flashlight with a lighted tailcap or switch and you’re not going to be using it for at least a couple days, it’s best to just shut off all power. An easy way to get a rough estimate is to just measure the battery voltage, preferably not fully charged, and then let it sit a day or two and then see how much the voltage dropped. That will get you into the ball park.