Restoration of Rechargeble COB work light with broken driver + DIY Custom driver circuit + li-ion battery charger board with replaced current resistor to 2.2k Ohms for 0.5A + li-ion battery capacity tester with transistor BC547 and red & green DIFF LEDS + LM317T 1.2V-25V Adjustable Voltage Regulator and B4.7k Ohms lenear resistor with switch

Step 1: Circuits and Parts

I used two drivers. The first one is powered 4 SMD leds connected in parallel = 3W both of them. The second driver is powered a single SMD LED = 1W with a heat sink. Also i'm using LM317T to control the output voltage from a single cell 14430 Li-ion Battery 3.7V 400mAh (Real mAh). So here are the parts we'll need...

Parts for >>> LM317T 1.2V-25V Adjustable Voltage Regulator and B4.7k Ohms lenear potentiometer with switch:

LM317T x1
270 ohm 1/4W resistor (red, violet, brown, gold) x1
100nF 50/63V ceramic or polyest. cap-s x1
100uF 35V electrol. cap. x1
10uF 16V electrol. cap. x1
B4.7k Ohms lenear potentiometer with switch x1

Parts for >>> The custom LED driver(-s):

4.7uF 50V electrol. cap-s x2
150pF 50/63V ceramic discs cap-s x2
100nF 50/63V polyest. or ceramic (code: 104) cap-s x2
100k ohm 1/4W resistors (brown, black, yellow, gold) x2
BC327 TO-92 transistors (P50V,0.8A,0.625W,100MHz,7a) PNP x2
BC337 TO-92 transistors (N50V,0.8A,0.625W,100MHz,7a) NPN x2
1N4148 zener diodes x2
22uH (Microhenry) inductors (red, red, black, silver) x2
A single sided piece of experimental PCB board x1

Parts for >>> Li-ion battery charger board with replaced current resistor:

I'm using a 2,2k Ohms 1/4W resisror to get current of 0.5A to extend battery's life...
Resistor color code is - red, red, red, gold SMD code 222

Parts for >>> Li-ion battery LED level indicator/tester:
BC547 TO-92 transistor (N50V,100mA,0.5W,300MHz,7a) NPN x1
1N4148 zener diode x1
3mm DIFF LED GREEN x1
3mm DIFF LED RED x1
220 ohm 1/4W resistor (red, red, brown, gold) x1
1k ohm 1/4W resistors (brown, black, red, gold) x1
single small push button to test 14450's сondition / charge x1
small single sided pieces of experimental PCB board x2

Other struff:

Wires, project box, switch ON-OFF-ON, potentiometer knob (black and yellow), 3mm led holders......