Open Source Li-ion Charger Board

[Hiemal]

Hey guys... I had nothing better to do at the moment, so I went ahead and made up a quick li-ion charger board for those who desire one... this should be 500 times more reliable than a cheap chinese knockoff, and it's also a lot smaller too!

Parts list;

5988070107F - DIALIGHT - LED, 0603, GREEN, 20MCD, 570NM | Newark (optional, lets you know when the battery is charging)

MCP73831T-2ACI/OT - MICROCHIP - IC, BATTERY CHARGER, 500mA, SOT23 | Newark

LMK212BJ475KD-T - TAIYO YUDEN - CAPACITOR CERAMIC, 4.7UF, 10V | Newark(two of these) (C1 and C2)

CR0603-FX-2001ELF - BOURNS - RESISTOR, THICK FILM, 2KOHM, 100mW | Newark (one of these) (R1)

CR0603-JW-471ELF - BOURNS - RESISTOR, THICK FILM, 470 OHM | Newark (one of these) (R3) (also optional)

And of course, the board itself;

View attachment Li-ion Board.zip

which includes the schematic file and the board file.

This board will charge a li-ion battery at about 500 mA. I don't know if it will require heatsinking or not, as I included some thermal vias and large ground planes on the board... I'd recommend supplying the board with 5 volts. You can get 5 volts from a USB port, actually; If you'd like me to make a USB compatible version, just ask!

If you order the boards from OSH park, it costs $1.85 for three of these boards.

Total cost PER board is only $1.43!!!

Board size is 14 mm by 17 mm roughly.

If, you'd like to donate, just click this link below and enter an amount...

https://www.paypal.com/cgi-bin/webs...bn=PP-DonationsBF:btn_donate_SM.gif:NonHosted

Thank you very much for looking, and I hope you enjoy the board.

 

[ped]

Re: 18650 Charging Board

Good stuff

 

[flare09]

Re: 18650 Charging Board

feel like swapping out some components to make that lithium iron charger?

 

[AnthoT]

Re: 18650 Charging Board

Looks great LeQuack! :beer:

 

[tsteele93]

Very nicely done, all the way around!

 

[Fiddy]

ill have your children if you put a volt and/or ammeter on it

 

[Hiemal]

i tried integrating a USB port into the board itself... but I don't know if it'll work or not.

View attachment liion.zip

Try this one at your own risk. The boards need to be 2.4 mm in thickness for it to work properly.

And Fiddy; I don't see how I could add a volt/ammeter into the board... unless you buy the volt meter separately, and just use it on there of course.

 

[Wolfman29]

Hey, the key question here is, do I have to disconnect the charger circuit from the li-ion battery to discharge the battery, or can I make it a permanent charging port?

 

[Hiemal]

Hey, the key question here is, do I have to disconnect the charger circuit from the li-ion battery to discharge the battery, or can I make it a permanent charging port?

I'm pretty sure that once you disconnect the charger from your 5 volt power source, you can use the battery for whatever you want.

If you keep the power connected and use the battery, then the charger would attempt to "help" out I guess with supplying power to whatever it is your battery is supplying.

Either way it's not dangerous to the battery, to the charger, or to whatever you're powering. The charger IC for this board has built in thermal regulation; so even if it does get toasty, it'll automatically shut off.

 

[flare09]

hey fiddy, i just bought one of these Ultra Mini Size Blue LED Volt Meter DC 3.2V~30V No Need Power | eBay ill let you know how it is. its tiny though all the circuitry is behind the led display. and there is an ammeter i believe from the same seller thats about the same size

 

[benmwv]

Nice job Quack!

I've been using that IC to charge my batteries for a long time now, it works great. It was actually the first board I ever made. I think RHD has a charger for like 12 cells or something crazy with it too.

Here's mine:

 

[Benm]

I'm pretty sure that once you disconnect the charger from your 5 volt power source, you can use the battery for whatever you want.

With the charger circuit still connected?

I'm not familiar with the chip used, but some will actually drain the battery if they are kept connected while there is no 5v supply present.