Wednesday, 29 January 2014

Which battery type should I use?

Disposable Alkaline batteries have now become the standard for AA and AAA cells. There are however some interesting alternatives depending on the use you want to make of them:

Carbon monoxide detector: your best
choice are disposable Lithium or
Alkaline batteries
For emergency/critical appliances such as smoke or carbon monoxide detectors, a torch (flashlight) or any device that consumes very little energy or is used very occasionally (e.g. for emergencies):

  • These devices consume very little to no energy (unless e.g. an emergency occurs)
  • They need reliable batteries to function whenever the need arises with as little maintenance as possible
  • Alkaline or Lithium disposable batteries are they way to go: they have the longest shelf life
    shelf life = will remain fresh if unused
Favourite toy of my kid: I'm
definitely using rechargeable batteries
Heavily used or consuming devices such as toys, torches (not emergency ones), tools and other things that require frequently changing batteries
  • We're talking about tons of batteries used here. What you will want is definitely rechargeable batteries.
  • The best value for money is NiMh rechargeable batteries (you should always buy low self discharge) the point here is (of course) to benefit from reusing the same cells.
Power hungry/high drain appliances such as cameras, flashes, rc cars...
The flash of your camera needs to
charge quickly: NiMh batteries come
with the required punch.
  • You will want a battery capable of delivering a lot of energy very quickly... it is like using a wide pipe to deliver large amount of water (energy) in a very short time. For large currents, you need a low internal resistance to let energy flowquickly. As a result, the battery will heat less for the same 'effort'.
  • Quality NiMh batteries are best suited for high drain applications
    Note: In the RC world people are now almost always using LiPo (Lithium Polymer) batteries as these (unstable and dangerous) batteries can deliver tremendous amounts of energy very quickly. These are however never packaged in the AA or AAA formats as they do not have the same voltage and would fry most appliances adapted to Alkaline batteries.
Low-drain devices and/or little used devices
Remote: the real question is
'how much you watch the TV?'
  • If your device needs occasional battery changes. I would say that for at least once every two year, you will probably want a low self discharge rechargeable NiMh you should otherwise go with disposable Alkaline or Lithium batteries.
  • Rule of thumb: low self discharge rechargeable NiMh cost about 3 times more than an disposable Alkaline equivalent and should at least 6 years. I therefore recommend using a low self discharge NiMh for any device that requires changing batteries more frequently than once every two years.
Your cheap and offering battery operated presents 
  • You're looking for the cheapest AA (or AAA) cell.
  • Look for 'Heavy duty', 'General purpose', 'Carbon zinc' or 'Zinc Chloride' disposable batteries (not Alkaline). These are the worst and cheapest disposable batteries there is. You've been warned.
Cold ... but not battery operated ;-)
Photo by Alan Wilson
Cold temperatures
  • Rechargeable NiMh and disposable Lithium batteries perform much better than Alkalines ... down to -20°C ... brrr
You absolutely want to avoid battery leaks
  • Rechargeable NiMh and disposable Lithium batteries are your safest choice.

Leaked Alkaline battery
Photo by Tùrelio