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Just throwing out a question to everyone out there. For those of us that use speedlights, and have or considered using an external battery pack for a speedlight, would you prefer a AA (NiMH) based unit (like the Nikon SD-8/SD-9, Canon CP-E4) or external battery pack that used a rechargeable Li-Ion battery (Quantum SC/Quantum Turbo)?

Both systems seem to have their advantages and disadvantages.

The batteries should be the same ones that are used in the flash. Otherwise we'd have to lug more chargers around. One should be able to just use any amount of batteries in a pack. 3, 4, 6, 8 whatever you have, rather than being locked into using 6 or 8 or whatever.

Slightly off topic... Ni-Zn are just around the corner....
http://www.greenbatteries.com/nickel-zinc-aa-rechargeable-batteries.html

alot of the press crew have the quantumn packs but even they say its not perfect especially for th hefty price tag

i use the sd8a and its enough to tell you the truth i dont shoot that fast so i can even work with 4 batteries in the flash i use the powerex 2800 works a charm

I am not sure if i would want to put 1.65V batteries into devices designed for 1.5V batteries....that in itself can cause issues. That voltage stack up...2AA device designed for 3.0V will have 3.3V, it can cause a hazard (esp on less robust devices)

I can imagine the Quantum units being less than perfect...imagine getting a flat, but they do provide a crap load of juice quickly so your recycle is insane (note this can be dangerous as well)

I use a Canon 580EX (4xAA) with a CP-E3 (8xAA) and have no complaints with it. Well, you need to be careful with the plastic clips in the CP-E3M magazine which hold the batteries in place, but that's it (and I have a spare magazine if it ever becomes a problem).
Recycle time is amazing, it lasts for ages, it's conveniently portable, and I don't need a different battery charger.

Cameron, don't worry about the different voltages too much: these external battery packs have their own voltage multipliers and feed directly into the high-voltage power inputs of the flashes. With the DIY battery packs that connect in place of the flash's internal batteries the voltage is important as it has to feed both the flash control electronics and the voltage multiplier that charges the capacitors.

With the 580EX and 580EXII you can select (via a custom function) to charge the flash from either just the external power pack (or the internal batteries if the power pack is not connected) or from the external and internal batteries together. I suppose the recycle time might be even faster if you tell it to use both sets of batteries concurrently, but I use it in the "external only" mode. Once the internal batteries are flat the flash can't function (the LCD/triggering/TTL/etc functions need them) even if the external pack has power.

The way I use it, it will run for ages but if I'm using it a lot and the external power pack runs down later in the day (shown by the fact that the CP-E3's LED goes off, and the flash refuses to charge) I can unplug the power pack and the flash will continue to run on the internal AAs (which up until that point have only had a tiny draw). So while I'm switching new AAs into the CP-E3, if a shot opportunity comes up I can at least make the shot. Then I reconnect the CP-E3 and keep working.
Currently I use Imedion/Eneloops in the flash, and either the same or 2500 NiMH cells in the CP-E3.

good info guys - I'd never asked the question about the CP-E3 but now i know the answer
Deb

I didnt know that the external flash battery packs have inbuilt voltage multipliers, but over-volting something like a LED torch will usually damage the device.

Huge thanks for the info on the CP-E3 though. Keeps you thinking about how they can make them better. The battery holder in the CP-E4 is still pretty fragile looking (I sold one recently).

DaveB wrote:I use a Canon 580EX (4xAA) with a CP-E3 (8xAA) and have no complaints with it.
...
So while I'm switching new AAs into the CP-E3, if a shot opportunity comes up I can at least make the shot. Then I reconnect the CP-E3 and keep working.
Currently I use Imedion/Eneloops in the flash, and either the same or 2500 NiMH cells in the CP-E3.

Thanks for the info Dave. I use 580EX II and I was thinking of getting the external packs. I like your tip about keeping the internal batteries for backup firing (cover fire).

I've been using the 2500Mah batteries from Aldi - lots of em - cos they're cheap - $10 for 4pack. They work great. Prior to that I was using the green energisers 2450Mah. They all work fine and I charge them all in the energiser 1hr charger - which also works great (but only has a 30day warrenty).