In this Instructable I will show you how to make a cheap smart charger for your airsoft gun.

Step 1: What You Need

What you will need.

1 regular factory airsoft charger. (free, comes with gun)

1 cheap wal-mart garden timer. (around 5-10 dollars)

Step 2: Making the Charger

Now all you do is plug the airsoft charger into the timer and you are done.

Step 3: Using the Charger

To use the charger you just set the time you want the timer to shut off and plug it in. No more overcharged batteries!
(for some timers you can even set the hours it will run and the time it shuts off)

If you are unsure on how long to charge your battery then keep reading.

Step 4: How Long to Charge the Battery

If you don't know how long to charge your battery then all you have to do is look on your charger and there should be a label. On this label is listed the chargers info. All you need is the "output" section. To figure out the charging time just divide your battery's mAh capacity by the chargers output mAh capacity. Then multiply that by 1.4 for NiCad batteries or 1.5 for NiMh batteries.

For example my chargers output is 250 mAh and by battery (NiCad) is 1200 mAh so it should look like this.

1200/250 X 1.4= 6.72

So I charge my battery about 6-7 hours or until it gets hot to the touch.
Always stop charging your battery when it gets hot to the touch!