A few practical tips:
- Never charge primary batteries.
These get hot and may leak or even explode. - Fully charge rechargeable batteries the first time.
This is because they are supplied uncharged by the manufacturer.
This first time charging always takes longer than normal and should preferably be done the slow way (i.e., not fast charging). - Do not charge the battery in cold environments (below 0°C).
Once charged, however, they are excellent to use in cold conditions.
Always ensure that the battery is fully charged the first time; do not remove it from the charger halfway through the charging process, this is very detrimental to the battery.
Also, for the life of the battery, it is important that the battery be fully used up (or electronically discharged) before recharging.
The first time, or after prolonged rest, the battery may not be fully charged and may not reach its capacity.
Fully discharging and then recharging the battery will promote capacity uptake.
For ease of use of NiMH batteries, it is often desired that batteries are full within 1 to 2 hours.
Given the composition of NiMH batteries, fast charging within that time is not recommended, and chargers made specifically for these NiMH cells take at least 3 to 4 hours.
After the charging process, the charger should be able to switch to trickle charging.
If the batteries remain in the charger for several days (or weeks) after charging, the trickle charge current ensures that the battery remains full at all times.
Self-discharge is then compensated by the charger “trickling” additional energy. Read more about how to charge a battery here.
