5V li-ion batterry charger - concept

I exchanged the cap/battery with 100mOhm and 4.2V voltage source, unfortunatly EC frezzes :-(

Its because enormous gain of OP-amp - ode sover runs to singularites - I think...why would you replace cap anyway?

Its easier to test, i can change the voltage as i like and together with Ri its as good as a real battery, an constant voltage is like a infinite capacitor, but you dont have to watch the full charging cyclus. You can start with 3.7V and increase as you like step by step, makes it much easier to test.

Don't get me wrong, I understand how this works. And it does. What I have a problem with is from a end user standpoint. What is the red LED for? As the charge (or the non-inverted input of the right/cutoff op amp) approaches 2V, the red LED turns off. Here's a suggestion, a common approaches for chargers with LEDs look like this: A) Red = not connected to device, flashing green or amber = charging, solid green or amber = full charge. B) No light = not connected, amber = charging, green = charged. C) No light = not connected, LED (any color) blinking = charging, LED solid = charged. I challenge you to implement one of these features so that your charger not only works, but is also idiot-proof for the end user. Remember, the end user of your product will have next to no knowledge of electronics in most cases.

Marketing agreed "Lahola, jipijeeee" , but from engineering its waste of time ;-)

I've only ever seen battery chargers have red leds that turn off when charge is complete. no greens or blues or yellows or blinking. Can't be that hard.

Depends. I can't recall ever seeing a phone charger with one. RC stuff I have has all kinds of different LEDs. My cordless drill charger blinks when charging, then stays lit when full. There's a whole gambit of ways to go about it. Really, my point was that red LED is kind of useless from a end user standpoint, so if it's going to utilize LED indicators, it should be a little more useful.

marketing said: @rbrtkurtz please build a lasershow and smoke machine for our newest charger product and @stanke please continue with the little rest we need for the core function, but please dont spend to much money. @faceblast please keep an eye on both

lolz

hurz - 10/10, making aditional leds and using more op-amps seems to me like waste of time/money. I used énly leds that are showing eferything you need to know - red light means battery is exhausted. almost no light means that it is going to finish, green light - battery is ready. Id rather mention it in manual instead of adding more price which could easily double the price of charger. Just to be clear - this isnt complete charger - thermofuses, overfoltage surges and other safety-related parts are missing!

Ill add those leds for rbrtkurtz :D search for fancy "LED charger"