Taking care of your rechargeable batteries

I am amazed by the modern rechargeable nickel-metal hydride (NiMH) battery. I once have a set of freshly recharged battery but when I wanted to use them 2 weeks later, the power was gone!! So, I read up about this battery and summarise it here so that everyone can use it properly without surprises … haha… maybe more surprises!

  1. Do not completely discharge NiMH battery. Otherwise it may cause permanent damage. This means that you must not store this type of battery! So, don’t leave your camera, handphone or whatever without use for a prolong period.
  2. NiMH battery has high self-discharge rate. On the first day, the discharge is 5-10%. Then 0.5-1% everyday after that. So this battery is not very good for light duty usage, eg, clock, remote control…
  3. You can recharge as often as you wish. Unlike NiCd battery, it does not have “memories”
  4. You must use NiMH charger otherwise permanent damage will occure! This is due to the different charging characteristic of the battery.
  5. You must recharge all the cells and use them together. Don’t mix cells, eg, some used and some freshly recharged. It can cause permanent damage.

Ok, I think the above are just summary I got from wikipedia and other sources.

what about laptop batteries and hand phones batteries does it apply to the same way?

Many batteries are also made from Lithium ion technology. You just check the label on the batteries for the word NiMH to confirm. Perhaps I should check out the characteristic of those batteries also.

NiMH batteries are usually those AA & A size batteries.

In the order of supremacy:

Fuel Cell
Lithium Polymer
Lithium Ion
Nickel Cadium
Nickle Metal Hydride

Any laptops you use nowadays normally comes with lithium ion. You can recharge from any point and there wouldn’t be any issue of overcharging or false capacity reporting as it has chips to control its charge and discharge including capacity cycles.