D-LI90 Idea

Started Nov 21, 2012 | Discussions thread
James O'Neill
Veteran MemberPosts: 3,927
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Re: D-LI90 Idea
In reply to iamphil, Nov 22, 2012

iamphil wrote:

James O'Neill wrote:

KentG wrote:

I doubt you would gain anything at all. Just look at the NiMH AA batteries. The Sanyo Eneloops are by far the best and yet they have a lower amp-hour rating than many of their cheaper competition, yet last longer both in the camera and on the shelf.

Be aware that there is NO standard for amp-hour ratings.

You would think that if device draws 250ma and the battery is rated at 2000maH you'll get 8 hours of life right ?

Wrong. Some battery makers will take the life down to 0 volts. But the camera stops working when the battery is at maybe 0.9 volts ... so the "full charge" to "stops working" time is a lot smaller. Another battery maker might take life down to half the initial voltage, or some other step.

I've got 2900 maHs which last less well than 2400 ones *of the same brand*. 2000 Eneloop-types (Sanyo, Panasonic, same 3rd party) all outlast both. It's a question of the way the voltage holds up - is it 1.2v at full chare, 1.1 at 25% change and then suddenly 0 or is it 1.2 at full , 0.6 at half and 0.3 at 25% ? The former batter will give almost its full charge to the camera and the later won't. And if you made the latter you'd measure capacity down to empty.

But the protection circuits in these batteries would never allow a device to drain the cells beyond a critical point.

Li_ion have such a circuit, I'm pretty sure AA NiMHs don't. Hence a 1500-rated Li-ion gives more hours of use at the same current than a higer rated set of AAs.

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