6V Solar battery charger circuit using LM317

Today we are going to learn how to make a simple solar battery charger for 6V battery.

The solar charger we are going to make is based on LM317 regulator IC. When battery has reached is full charge voltage (Battery voltage is higher than VDz + 0.7v), our charger circuit automatically cuts the charging to protect the battery form damage. The LED light will indicate the full charge state in the battery.

Our charger circuit will work only when the voltage level from the solar panel is much higher than the battery voltage, unlike the solar charger with regulator and controller that can charge regardless the solar voltage.

Part List:-

Solar - 12V solar cells array

C1 - 470uF electrolytic capacitor rated 25V

D1, D2 - 1N5400 or any rectifier diode rated 2A minimum

Dz - 1N5235B or any 6.8V zener diode

R1 - 3 kilo ohms 1/4Watt

R2 - 330 ohms 1/4Watt

R3 - 560 ohms 1/4Watt

R4 - 2 kilo ohms 1/4Watt

LED -3mm or 5mm Red or any low power LED

Q1 - 2N2222, CS9013, or similar NPN transistor

Bat - 6V lead acid battery

Make the above simple circuit to charge your 6V battery from clean and environment friendly energy.

If any query arises pleas ask them in the comment section, i will be happy to answer.

Simple 2.7V 200mA USB Battery Charger Circuit

Today we are going to learn how to make a 5V 200mA or more amperage USB Battery Charger circuit for NiCd battery or power source circuit

This is a simple charger circuit for nickel-cadmium battery (NiCd) that can be connected in your USB port of computer or laptop.

The charging scheme employs only a constant current charging.

The two NiCd cells are connected in series and charge at 200mA current. Charging current is controlled by zener diode D1 and resistor R1. We can increase or decrease the current by using the approximate equation:
Current = VD1/R1; where VD1 is the zener voltage.

The use of D2 diode is to limit the voltage across the battery terminals, thus protect the battery from damage. Charging time of the fully discharged battery is given by the formula:
Time = Battery rating / 200mA ; where Battery rating is in mAH.
Example: battery rating 220mAh;
Time = 2200mAH / 200mA = 11 hours; meaning do not let battery charged more than 11 hours.

Part List:-

D1, D2 - BZX84C2V7, 1N5223B, or any 2.7V zener diode 1Watt

R1 - 10 ohms 1/2Watt

R2, R3 - 2 kilo ohms 1/4Watt

Q - 2N2907, 2N4403, or any similar PNP transistor

Make the above circut and enjoy charging. For any further querry please ask them in the comment section, i will be happy to help.