# Why not lithium ion for speedlight?



## tecboy (Nov 7, 2014)

Why not have lithium ion for speedlight?  Is it because the lithium ion is far too expensive?  Lithium ion is pretty much we use for laptops and cell phone on these days.  Thought?


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## MOREGONE (Nov 7, 2014)

Godox is now making Li-On battery powered speedlights.

Look really nice too. One of the commenters said he got 2000 shots off one battery at a wedding. I am researching how well they work with the Yonguo 622 triggers and how dependable the flash is over all.

http://amzn.com/B00M2JG7SQ


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## KmH (Nov 7, 2014)

A key factor often needed when using a speedlight is cycle time.
Li ion don't cycle as fast as NiMH.
NiMH is the best battery type for use in speedlights.

But go ahead and use the Li ion if you want to re-invent the wheel.


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## tecboy (Nov 7, 2014)

KmH said:


> A key factor often needed when using a speedlight is cycle time.
> Li ion don't cycle as fast as NiMH.
> NiMH is the best battery type for use in speedlights.
> 
> But go ahead and use the Li ion if you want to re-invent the wheel.



Really?  How about LiPo? But, that would be too dangerous. LOL!!!


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## WayneF (Nov 7, 2014)

KmH said:


> Li ion don't cycle as fast as NiMH.



True if speaking of AA lithiums, but I'm not sure that is at all true of Li-Ion.  At least Godox says their Li-ion battery speedlight recycles full power in 1.5 seconds.  Touts it as a feature.   NiMH is very good, but not that good.  

The confusion might be about the Lithium AA cells.  Those AA cells do recycle slowly.  Energizer limits their current peaks for safety.  The older Energizer Advanced Lithium limited peaks to 2 amps, and in flashes, they were slower than alkalines.  The current Enegizer Ultimate Lithium relaxes that to 5 amp peaks, and these are as fast as alkalines.  NiMH is faster if speaking of them.

But  apples and oranges.  The AA lithium cells are 1.5 volts, and are an entirely differently chemistry than 3.6V Li-ion.    Simply not comparable.


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## KmH (Nov 7, 2014)

Yep. The discussion was about speedlights that use AA batteries.


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## WayneF (Nov 7, 2014)

You may have assumed AA, but no one had mentioned AA.  The topic was Li-Ion.  

This one was mentioned by Moregone   http://www.amazon.com/dp/B00M2JG7SQ

And the OP tecboy mentioned "like laptops and cell phones".  That's not AA either.  Both specifically mentioned Li-Ion.


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## tecboy (Nov 7, 2014)

WayneF said:


> You may have assumed AA, but no one had mentioned AA.  The topic was Li-Ion.
> 
> This one was mentioned by Moregone   http://www.amazon.com/dp/B00M2JG7SQ
> 
> And the OP tecboy mentioned "like laptops and cell phones".  That's not AA either.  Both specifically mentioned Li-Ion.



I don't mind having discussion about AA.  I thought lithium ion is more efficient, but I was wrong. We are using it on our dslr's body.  I thought why not on the speed light.


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## WayneF (Nov 7, 2014)

Dunno...    My guess is the easy availability of AA batteries might be a consideration?

Also the cost of Li-ion is pretty high.  They have to have a safety protection chip in them, called a coulomb counter.  Prevents overcharging, also is like a fuse to prevent high current surges in or out.

Or probably just that things are slow to change, but all things eventually change though.    You have pointed out the first one.

Wikipedia has a long list of types of lithium batteries
Lithium battery - Wikipedia, the free encyclopedia

None there say lithium ion, but I think that just means rechargeable.
The Li-iron (1.6v) is the only AA, and is NOT rechargeable, and not Li-ion and not 3.6V.  A whole other story.

Another page here
Lithium-ion battery - Wikipedia, the free encyclopedia

The characteristic of lithium is high efficiency.   The chart gives wh/kg which is watt hours / Kg.

watt hour = mah * Volts / 1000.

So... one Eneloop NiMH is 1.5V at 2000 mah, or 3 watt hours. Four should be 12 watt hours.  They weigh about 1 ounce, 4 ounces is 0.113 kg, so that is 12  / 0.113 = 106 wh/kg, more or less.  

Chart suggests lithium is 3x that (energy per kg).


EDIT:  Oops!   I should have used 1.2V for NiMH.     1.2V x 2 ah = 2.4 watt hours.


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## Didereaux (Nov 8, 2014)

Syl Arena did a pretty thorough comparison of various batteris for the Speedlites.  The Li-Io had very long recycle, and hot.  I think his results are on line, and also in the Speedliters Handbook, if I remember correctly.


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## WayneF (Nov 8, 2014)

I have not seen the article, but since there are no rechargeable lithium AA batteries to go into speedlights, are you sure he meant Li-Ion?   Because, the Godox (above in this thread) claims 1.5 seconds from their Li-ion. That's a little faster than NiMH.  The battery is comparable capacity and price as camera batteries.

The Enegizer lithium AA batteries are not Li-ion.  And yes, they are slower then NiMH.


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## petrochemist (Nov 8, 2014)

Li ion batteries are particularly good for continuous high drain applications, which flash isn't for most users. In addition they are not found in standard sizes - every camera I have that has Li ion batteries takes a different version!
I'm sure it would be possible to make Li ion batteries to fit in a flash gun that will take AA batteries instead (Pentax does something similar for some of their DSLRs) but the Li ion batteries are unlikely to offer enough advantage to generate the sales to make it worthwhile.

It would also be possible to make a Li-ion battery in the form factor of 2 AA batteries (side by side). This would be great for many applications but would encourage the use of mixed battery types particularly in devices where three AA cells are needed (Mixing battery types in series is not a good idea!).


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## Didereaux (Nov 8, 2014)

WayneF said:


> I have not seen the article, but since there are no rechargeable lithium AA batteries to go into speedlights, are you sure he meant Li-Ion?   Because, the Godox (above in this thread) claims 1.5 seconds from their Li-ion. That's a little faster than NiMH.  The battery is comparable capacity and price as camera batteries.
> 
> The Enegizer lithium AA batteries are not Li-ion.  And yes, they are slower then NiMH.



These are the ones he tested '
*Energizer® Advanced Lithium AA Batteries'*
Energizer Advanced Lithium AA Batteries


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## WayneF (Nov 8, 2014)

Didereaux said:


> These are the ones he tested '
> *Energizer® Advanced Lithium AA Batteries'*
> Energizer Advanced Lithium AA Batteries



Thanks, that's what I thought.  

Those are NOT 3.6 volt lithium ion rechargeable batteries.
Those are 1.6 volt non-rechargeable AA cells.  Not Li-ion.
There are no AA rechargeable lithium ion batteries, which cannot be 1.5 volts.

See post #5 above.  Energizer Advanced is the old version, limited to 2 amp peaks (safety), and are slower recycle in a flash than are alkalines.

The current newer version is Energizer Ultimate, now only limited to 5 amp peaks, and they are about the same speed as alkaline.

NiMH is faster.

Lithium ion should be a little faster yet (based on the 1.5 second Godol specification for theirs).


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