Alkaline v NIMH

[inka]

Hi,
Is there a notable difference of brightness if i use 4 NiMH C cells instead of 4 alkaline cells ?
I dive once a month, 45' dive, in clear to "green" water, and like to buy NiMh if the difference of brigtness is small.
Thanks

 

[Kupu]

Although I have not used NiMh C cells, I do use AA NiMh in my dive lights and find the rechargeables to be as bright as the most expensive alkaline batteries as long as the rechargeables are fully charged before the dive. I would expect that would be true with C cells as well...

 

[LBHeyman]

I can help you out on this. The batteries are the same voltage. The light will not be any brighter. If you only dive once a month or so and would like rechargeable batteries go with NiCD. They are half the price of the NiMH and for your application would do just fine. The difference between the NiMH and the NiCD is that the mah (milli amp hours) is more on the NiMH. They all have the same voltage. (I build battery packs on the side for Batteries Plus) Hope this helps.

 

[inka]

Thanks for your reply. I can just find Radio Shak 1,2 V NIMH batteries , so because of the difference of output voltage ( 6V for Alkaline against 4,8V for NIMH) i was worried to loose brightness ( UK C4 eLEd)
Thanks again

 

[MikeRD03]

Hi inka,

In the same diving light normaly NiMH accus are much brighter than ANY alkaline cell if it is unregulated (the most lights are). Why is that so? To get the answer you have to look at the discharge curve of both cell typs. Alkaline starts at a slighty higher voltage than NiMH but drops quite fast and goes down over time like someone would except.
NiMH has a different curve. It drops a bit at the beginning and keeps quite stable over 80% burntime. Than it drops very fast. So after the first 5 minutes any NiMH driven light will be brighter - but at the cost of burntime of course. And don´t worry about the printed Voltage -NiMH has a lower voltage course they START lower. But over time they have MORE.
Besides that accus are less expensive over time when used and recharged on regular basis and are much better for our enviroment seen on their lifetime.

So if you can - allways choose NiMH!

Hope it helps

greets
MikeRD03

 

[LBHeyman]

The NiMH are rated at 1.2 but when fully charged are the same 1.6 +/- a tenth or so.

 

[inka]

Thanks, LBHeyman, i am going Nimh so
Regards