Monday, March 26, 2012
Recharge Dry Cell Non-rechargeable Battery with Vehicle Accu
Several dry cell batteries are not designed for recharge (non-rechargeable), but can still be recharged, though not as good as the rechargeable type battery. In the previous article, it is discussed how to recharge dry cell non-rechargeable battery with an adapter. While in this article, it is discussed how recharge dry cell non-rechargeable battery with a vehicle accu (battery).
This procedure is not applied to all types of rechargeable batteries. Use the appropriate charger to recharge rechargeable batteries.
A non-rechargeable batteries size AA with voltage 1.5 volt can draw current of 10 amperes when recharged with 12 volt battery. That large current will damage the battery, the heat generated can make the battery explode because the gas pressure inside. It requires the resistor to resist the current.
Resistor needed is approximately 33 ohms and 5 watts. To be safe, then you should use a 10 watt resistor. But 10 watt resistor is much more expensive than the total price of 10 each of 1 watt resistors, because 10 watt resistor is more rarely used than 1 watt resistor. So if using resistor, it is cheaper to use 10 pieces of 330 ohm 1 watt resistors which are connected in parallel so that their total value become 33 ohms. Can also use 10 pieces of 1 watt 3.3 ohm resistors which are connected in series.
Another way is to use a 12 volts 5 watts automotive bulb type C5W as I use. Bulb is mounted on fuse socket. Price of bulb and fuse socket is very cheap, I get them with price below US$ 0.5 total for both.
Procedure below describe how to recharge non-rechargeable dry cell batteries which are commonly used for wall clock, flashlight, toy, remote, etc. with size of D, C, AA, AAA, PP3 (9 volts), and coin size batteries as well.
Make sure the batteries to be recharged in good condition. If there are signs of leakage on battery body such as moisture, oil, stain, rust, etc.; the battery can not be recharged. Replace it with a new one. Fluids that leak from battery can damage the gadget that uses that leaking battery.
Measure voltage of battery to be recharged by multitester. Voltage should not be too low. For 1.5 volts battery, the voltage is not lower than 1.2 volts. For 3 volt battery, the voltage is not lower than about 2.4 volts. For 9 volt battery, the voltage is not lower than 7.2 volts. If the voltage is too low then it will be difficult to recharge.
Photo below shows an AA size dry cell battery is recharged with a vehicle accu. Note the automotive bulb is brightly glowing when the bulb is resisting current to the dry cell battery.
Cable connection diagram is as shown below.
Shown in the photo below detail of automotive bulb 12 volt 5 watt type C5W, along with the fuse socket that are used.
Can also use a continuity tester / electrical circuit tester as photo below as current resistor, but it is more expensive than the above system.
Recharge battery for about 1-2 minutes. Immediately stop if the battery get warm. Temperature rise is not due to heat from your hand, but because of chemical reactions inside the battery. Do not continue recharge if battery is hot and can not be hold by hand, or more than 40o Celsius. Wait a while to cool the battery by itself.
Check battery voltage with multitester, whether it reaches its normal voltage (1.5 volt, 3 volt, or 9 volt). If the battery voltage has normal already then it can be reused.
If the battery voltage is not normal yet, then continue recharge as above procedure. AA size battery will usually get a normal voltage after recharged for a total time about only 5 minutes. Bigger battery will need longer recharging time.
This dry cell battery recharge procedure can be applied when using other large current 12 volt sources such as power supply, large adapter, 12 volt battery charger, etc..
Recharge a dry cell battery is not only economical, but also help reduce pollution caused by battery waste. Carelessly discarded old or used battery will pollute soil and water. Make sure battery waste is discarded to a place that can recycle the old battery.
Video of recharging AA dry cell with vehicle battery, click here.