How to Charge NiMH Batteries
Use a wall mount charger or laptop adapter to charge the battery overnight., Use a power dissipating package to charge the battery at C/3.33 for 5 hours if you cannot wait the 15 hours required for the overnight method., Use a...
Step-by-Step Guide
-
Step 1: Use a wall mount charger or laptop adapter to charge the battery overnight.
Charge at C/10 (ten percent of the battery's rated capacity per hour.) For example, if you have a 100 mAH battery, you would charge it at 10mA for 15 hours.
Your battery is likely to contain an oxygen recycling catalyst to prevent overcharging, but this feature is not functional if the battery is charged at a rate exceeding C/10.
To preserve the life of the battery, do not allow a wall mount charger or laptop adapter to charge a NiMH battery for more than 13 to 15 hours. -
Step 2: Use a power dissipating package to charge the battery at C/3.33 for 5 hours if you cannot wait the 15 hours required for the overnight method.
Before charging, fully discharge the battery to eliminate battery memory.
You can drain the battery by allowing the charger to discharge it at 1 volt per cell.
Once the battery is completely discharged, turn on the charger for the required time of 5 hours. , This type of charger contains a temperature monitor so that venting or overheating does not occur.
It also senses voltage and current and adjusts itself accordingly.
To end the charging session based on unsafe temperature increases, set the dT/dt value at
33.8 to
35.6°F/minute (18.8 to 20°C/minute). -
Step 3: Use a microprocessor-controlled battery charger to charge the NiMH battery at 100 percent of its capacity for 1.5 hours.
Detailed Guide
Charge at C/10 (ten percent of the battery's rated capacity per hour.) For example, if you have a 100 mAH battery, you would charge it at 10mA for 15 hours.
Your battery is likely to contain an oxygen recycling catalyst to prevent overcharging, but this feature is not functional if the battery is charged at a rate exceeding C/10.
To preserve the life of the battery, do not allow a wall mount charger or laptop adapter to charge a NiMH battery for more than 13 to 15 hours.
Before charging, fully discharge the battery to eliminate battery memory.
You can drain the battery by allowing the charger to discharge it at 1 volt per cell.
Once the battery is completely discharged, turn on the charger for the required time of 5 hours. , This type of charger contains a temperature monitor so that venting or overheating does not occur.
It also senses voltage and current and adjusts itself accordingly.
To end the charging session based on unsafe temperature increases, set the dT/dt value at
33.8 to
35.6°F/minute (18.8 to 20°C/minute).
About the Author
Doris Rogers
Writer and educator with a focus on practical DIY projects knowledge.
Rate This Guide
How helpful was this guide? Click to rate: