When a battery wears, it tends to get a drop on voltage and increase on internal resistance. Then, the old battery’s output isn’t quite up to the mark, and it may have many bad effects, including wearing out the new battery, leakage or worse situation.
For example, if your dive light is powered by several NiMH AA batteries, mixing usage of new & old AA batteries may make the light with less brightness even at the beginning. And the performance is not good. Besides, old batteries tend to degrade chemically faster than new batteries, which may cause leakage, damaging the device.
If you puts the cells with wildly different capacities in series in a battery pack, the voltage across each cell will drift as the stack discharges. Eventually, the worst in the chain will reach an unsafe low-voltage, while the others still have plenty of charge to give. The weakest link will shut down the chain. And the circuit will not be able to use the rest of that stored energy in the other good cells. One single old or bad cell in a battery pack may drag down the entire pack.
So for your dive lights’ batteries, it’s suggested to replace them as a set, and to recharge them all on the same cycle. Some users put different coloured enamel paint on their rechargeable batteries, or mark numbers on them. So they will know the specific sets and charge them together. And it’s also better to prepare a set of new batteries than mix old and new.
For example, if your dive light is powered by several NiMH AA batteries, mixing usage of new & old AA batteries may make the light with less brightness even at the beginning. And the performance is not good. Besides, old batteries tend to degrade chemically faster than new batteries, which may cause leakage, damaging the device.
If you puts the cells with wildly different capacities in series in a battery pack, the voltage across each cell will drift as the stack discharges. Eventually, the worst in the chain will reach an unsafe low-voltage, while the others still have plenty of charge to give. The weakest link will shut down the chain. And the circuit will not be able to use the rest of that stored energy in the other good cells. One single old or bad cell in a battery pack may drag down the entire pack.
So for your dive lights’ batteries, it’s suggested to replace them as a set, and to recharge them all on the same cycle. Some users put different coloured enamel paint on their rechargeable batteries, or mark numbers on them. So they will know the specific sets and charge them together. And it’s also better to prepare a set of new batteries than mix old and new.
