Battery type for Emergency LED light.? (5W)

[treez]

Which battery types would you use for an emergency signage LED light?

NiCd or NiMH?

People tell me that NiCd is being phased out due to toxicity, so even though its cheaper, its best not to use it?

Maximum power from battery is 5W for 3hours

 

[Tahmid]

NiMH. Ensure that you keep in mind the charge and discharge curves of the battery when designing the charger circuit and when pulling the load.

Go through this: https://www.ehow.com/about_5422200_nicd-vs-nimh-batteries.html

You'll find your answer! :razz:

Hope this helps.
Tahmid.

 

[omega6]

Actually although NiMH is good, I'd consider using a lithium ion (li-ion) battery which has more power. li-ions usually last longer than NiMH batteries and don't suffer from the so called Memory Effect.

 

[treez]

But Li is very expensive isnt it?

NiCd is the cheapest.........if NiCd suffers the memory ettect...then wouldnt that mean it was illegal to use it in emergency lights?

 

[Tahmid]

But Li is very expensive isnt it?

Comparatively yes.

NiCd is the cheapest.........if NiCd suffers the memory ettect...then wouldnt that mean it was illegal to use it in emergency lights?

Depends on local regulations.

 

[treez]

I am not sure i know what regulations are....do yo uknow who decides it in UK?

 

[Tahmid]

I have no idea. See if you can find anything by googling.

 

[omega6]

The price of a typical li-ion battery depends on brand, no of cells (voltage) etc. NiCd is cheap but not so good as a power source in today's projects. NiCd's are bad for your health and environment too, bcoz it contains Cadmium which is toxic.

BTW you could find some affordable li-ions on ebay.

 

[treez]

thanks but i need to buy many for product launch.

 

[omega6]

if NiCd suffers the memory ettect...then wouldnt that mean it was illegal to use it in emergency lights?

What do you mean by illegal to use?

Actually Memory Effect means a NiCd wont charge properly. NiCd's should't be charged without fully discharging it.

 

[treez]

well, surely the regulatory bodies woul dban the sale of an emergency backup lighting system where the emergency light didnt come on properly due to memery effect in the nicd batteries?

 

[omega6]

Yes.. they will..

In reality all type of batteries do degrade in time. that said choose a effective power source which fits your budget and last long for your product.