Can Eneloop/LSD AAs reliably take a 2C discharge?

[Fallingwater]

I'm thinking of wiring a SSC P7 to a modded 12xAMC7135 driver. The idea is to heatsink the hell out of the LED (I have a special project for this...) and drive it at 1050mA per die.
Problem is, I'd like to feed this monster from four LSD NiMH AAs, and I'm wondering if they can deliver 4.2 amps while staying above 1V per cell for a useful length of time...
And yeah, I know battery life will be short - I'm hoping I can have regulation for about 15/20 minutes before voltage under load sags too much.

 

[was.lost.but.now.found]

I think from SilverFox's testing you will be fairly safe at 4A, with eneloop that is.

http://www.candlepowerforums.com/vb/showthread.php?t=79302

 

[45/70]

They will work at a 2C discharge, but if you look at was's post of SilverFox's graph, you'll see that the voltage drops to below 1.15 Volt rather abruptly. I had considered using eneloops for my ROP Hi (4.3A load) a while back, but because of the voltage dropping below 1.2 Volt, I went ahead and replaced my CBP 1650's with Elite 1700's instead. They remain above 1.2 Volt for most of the discharge. With a DD incan, this makes the light noticeably whiter, and brighter, as well. In fully regulated light applications, there is little consequence to using eneloops.

Dave

 

[Fallingwater]

Well, they seem to deliver about 1.5 amp-hours before they sag under one volt, below which threshold the driver would most likely drop out of regulation (depending on Vf of the LED). 1.5 Ah into a 4.2A load is about 20 minutes of runtime, which is pretty much what I was hoping for.

Now, since I can't actually buy true Eneloops around here... how do Hybrios compare in current delivery?

 

[45/70]

Now, since I can't actually buy true Eneloops around here... how do Hybrios compare in current delivery?

As I remember, I did see a graph somewhere, they perform similar to the RoyOVac Hybrids, which there is also a graph in Tom's thread that was linked to. Not quite as good as eneloops, but would probably get the job done.

Dave

 

[Fallingwater]

Hmm. That's not quite as good. I'll just order true Eneloops online then.
Thanks.

 

[Mr Happy]

Now, since I can't actually buy true Eneloops around here... how do Hybrios compare in current delivery?

It depends which Hybrios.

If you can examine them closely before purchase and they look like Eneloops (look for the larger squarish positive button with four holes one at each corner), then I think you will find they perform like Eneloops.

On the other hand if they have a slightly smaller and round positive button then I think they will perform less well, probably like Rayovac Hybrids (which is what I suspect they are underneath).

A third type has a much smaller positive button and has a pronounced valley around the cylinder at the positive end. I think these perform even less well again.

 

[Bullzeyebill]

Eneloops have been doing quite well in one of the USL's that js put together for Codeman. 8+amp draw.

Bill

 

[mdocod]

Eneloops should work fine for that application and deliver a very reasonable cycle life even after considering the abusive load.

 

[Popsiclestix]

My 15x Eneloop pack seem to be doing fine after 50 cycles with a 64458

(Initial amperage measured at tailcap is 8.5A)