Nicad vs Lithium Batteries: How to Maximize Life

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In summary: In NiCads the anodic reaction is Cadmium metal turning into Cadmium Oxide (on discharge) and vice versa on recharge. Both are solids. In low discharge the Cadmium Hydroxide crystals are relatively big, and therefore they passivate the anode. Less and less active surface of Cadmium is accessible for further dissolution (discharge). Hence the capacity drops. Deep discharge and subsequent recharge will break the crystals and form a new layer of small crystal, and thus restoring capacity. Full discharge doesn't mean "drain down completely". The deep discharge means going below 1 volt. The nominal voltage is 1.2 volts. This corresponds to 60
  • #1
ShawnD
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Nickel-Cadmium (nicad) batteries have the strange tendency to stop working unless they are completely drained then completely recharged. If the batteries are fully charged, drained maybe 20% then charged again, and this is repeated several times, the batteries simply don't work any more. If the batteries are fully charged, then drained down completely before being recharged, they virtually last forever.

Why is this?

Do Lithium batteries act the same way? I've heard that lithium batteries act completely different and that they should be kept as close to fully charged as possible at all times (charge em as often as possible).
 
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In NiCads the anodic reaction is Cadmium metal turning into Cadmium Oxide (on discharge) and vice versa on recharge. Both are solids. In low discharge the Cadmium Hydroxide crystals are relatively big, and therefore they passivate the anode. Less and less active surface of Cadmium is accessible for further dissolution (discharge). Hence the capacity drops. Deep discharge and subsequent recharge will break the crystals and form a new layer of small crystal, and thus restoring capacity.

Full discharge doesn't mean "drain down completely". The deep discharge means going below 1 volt. The nominal voltage is 1.2 volts. This corresponds to 60% discharge. The equipment is designed to stop operating below 1 volt, therefore the user may think that the battery is "fully discharged". If indeed you discharge it to death, for instance via a simple ohmic circuit, will simply die...
NiCads do not "last forever". Their lifetime is about 1000 cycles.

Lithium batteries have a totally different chemistry. In Lithium batteries, the solid lithium of the anode dissolves into a lithium ion, and there are no problems with crystals A safer battery (lithium metal is very reactive) is the lithium ion battery, where the anode is not metallic lithium, but rather lithium ion intercalated in graphite. Both types do not have a memory effect because the discharge product is not a solid coating the anode.





Originally posted by ShawnD
Nickel-Cadmium (nicad) batteries have the strange tendency to stop working unless they are completely drained then completely recharged. If the batteries are fully charged, drained maybe 20% then charged again, and this is repeated several times, the batteries simply don't work any more. If the batteries are fully charged, then drained down completely before being recharged, they virtually last forever.

Why is this?

Do Lithium batteries act the same way? I've heard that lithium batteries act completely different and that they should be kept as close to fully charged as possible at all times (charge em as often as possible).
 
  • #3


The reason for this difference in behavior between nicad and lithium batteries lies in their chemical composition. Nicad batteries use a combination of nickel and cadmium as their active materials, while lithium batteries use lithium as their active material. This difference in composition leads to different charging and discharging behaviors.

Nicad batteries have a memory effect, which means that if they are not fully discharged before being recharged, they will "remember" the shortened cycle and lose their capacity over time. This is why it is important to fully discharge nicad batteries before recharging them. On the other hand, lithium batteries do not have a memory effect and can be charged at any state of discharge without affecting their overall lifespan.

Additionally, lithium batteries have a higher energy density and can hold a charge for longer periods of time compared to nicad batteries. This means that they do not need to be recharged as often and can maintain their capacity even if they are not fully charged.

In conclusion, it is important to follow the recommended charging and discharging guidelines for each type of battery to maximize their lifespan. For nicad batteries, it is best to fully discharge them before recharging, while for lithium batteries, it is recommended to keep them as close to fully charged as possible. By following these guidelines, you can ensure that your batteries last as long as possible.
 

1. What are the main differences between Nicad and Lithium batteries?

Nicad (Nickel-Cadmium) batteries are rechargeable and have a lower energy density compared to Lithium batteries. This means that Nicad batteries have a shorter lifespan and require more frequent charging. On the other hand, Lithium batteries have a higher energy density, making them lighter and able to hold a charge for longer periods of time.

2. How do I determine which type of battery is best for my device?

The type of battery you should use depends on the specific needs of your device. If you require a lightweight, long-lasting battery, then Lithium is the better choice. However, if you need a more affordable option and don't mind frequent charging, then Nicad may be a suitable option.

3. How can I maximize the lifespan of my Nicad or Lithium battery?

To maximize the lifespan of your battery, it is important to properly charge and discharge it. Avoid overcharging or completely draining the battery, as this can damage the cells and decrease its lifespan. It is also recommended to store the battery in a cool and dry place when not in use.

4. Can I mix Nicad and Lithium batteries in the same device?

No, it is not recommended to mix different types of batteries in the same device. This can cause imbalance and potentially damage the device or the batteries themselves. Stick to using one type of battery for your device.

5. Are there any safety concerns when using Nicad or Lithium batteries?

Both Nicad and Lithium batteries have some safety concerns. Nicad batteries contain toxic chemicals and should be disposed of properly. Lithium batteries, on the other hand, can overheat and cause fires if not handled properly. It is important to always follow the manufacturer's instructions and handle these batteries with care.

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