Hobbies And Interests
Things You'll Need
Instructions
Charge your NiCad cell until it's fully charged. Remove it from the charger and leave it for about 30 minutes.
Read the side of the NiCad cell to ascertain the output voltage and the milliamp hours the battery is meant to produce when charged. It's likely to be 1.2 volts and 800 mAh, but it can vary.
Test the voltage using a multimeter. Set it to read voltage and then place the two prongs from the meter onto the two cell terminals. The red prong goes to the "+" terminal, and the black prong goes to the "-" terminal. Read the voltage and make a note of it. It is slightly higher than the voltage on the side of the cell, if the battery has retained a charge. If it's less than the voltage on the side of the cell, then you need a replacement.
Reset the meter to read mAh and then retest the NiCad cell. It reads the same as the mAh on the cell, if the cell is able to retain energy. If the reading is lower by more than 10 percent, you need to replace it.
Put your cell in the device it powers. Read the label on the side of the device to find out the mAh it consumes. Calculate how long your battery should last. Divide the mAh on the device by the mAh capacity of the cell. This tells you how long a good cell will power the device. For example, if the device consumes 400 mAh and the battery's capacity is 800 mAh, then 800 divided by 400 equals two, meaning a good cell will last two hours.
Turn on the device and let it operate for 25 percent of the time you have calculated. Using the previous example, let it operate for 30 minutes. Turn off the device and remove the battery.
Test the mAh left in the cell using the meter. Read the meter display. If the cell is operating correctly, the mAh left is about 75 percent of the first mAh reading you took. It the mAh used is more than 35 percent of the capacity, attempt to recondition the cell.
Put the cell back into the device it powers and turn on the device. Let it run until the device stops operating and then turn off the device and leave it for about 20 minutes.
Turn on the device again. You find it operates again. Let it operate until it stops and then let it rest for five minutes. Repeat the process until the device doesn't turn on and then remove the cell from the device.
Put the cell on charge and let it charge fully. Expect it to take longer than previously. Remove the cell from the device and let it rest for 30 minutes.
Test the cell's mAh using the meter to confirm it's fully charged. Put the cell in the device and turn it on for the same time as you did before. Turn off the device and remove the cell.
Test the mAh again. The reading indicates about 75 percent of capacity remains, if your cell is reconditioned. If the mAh has dropped by more than 30 percent of capacity, you need a replacement.