Warning: Energizer Ultimate Lithium AAs in Canon 580EX II

[RustBeltRaw]

On Friday I was in Indianapolis with the Detroit Derby Girls travel team shooting a bout in an area roughly 300-400% brighter than their usual practice space. One of my lights was a 580EX II powered by 4x Energizer Ultimate Lithium batteries in the flash, and 8x Powerex 2700mAh NiMh in a Bolt CBP-C1 auxiliary battery pack. The flash was running TTL controlled by a PocketWizard FlexTT5 with no compensation for about ten minutes when it stopped firing.

In that time, the Energizers got hot enough to melt their plastic wrappers and apparently did some considerable damage to the flash itself. The screen was off when I reached it, and cycling the power switch did nothing. I pulled the Energizers and replaced them with a fresh set of my usual Powerex AAs, but the flash still didn't power up.

I was using the lithium cells for their decreased recycle time - critical since the building was far brighter than usual, and I knew the flash would be firing at higher power to try to keep up. I've used lithium batteries in the flash before (they're recommended in the manual) with no issues, but I've probably never asked the flash to fire this hard and this often. Meant to load the battery pack with lithiums, but I had a brain fart and forgot.

I have a couple questions about how I could have avoided this. Did using the NiMh cells, with their higher internal resistance (therefore lower peak discharge current and reduced heat generation) in the battery pack with a different chemistry in the flash contribute to the problem? Why didn't the internal temperature monitor shut down the flash before it was damaged? In hindsight, it seems fairly clear the mixing chemistries between the pack and flash could cause a problem, but I haven't heard of this issue before.

Hopefully we can figure this out and save other photogs from either a $200 repair or a $480 replacement.

[DanK]

Thanks for the warning.

I am no expert, but my solution to the recycle time problem has been to use low-internal-resistance NiMH batteries. I had been using Ansmann, but I recently decided to try some Powerex. The drawback is that they don't retain their charge as well as the more conventional NiMH when stored. (If I have this right....)

[RustBeltRaw]

I am no expert, but my solution to the recycle time problem has been to use low-internal-resistance NiMH batteries. I had been using Ansmann, but I recently decided to try some Powerex. The drawback is that they don't retain their charge as well as the more conventional NiMH when stored. (If I have this right....)

The Powerex cells you linked (made by Maha) are the same ones I use most of the time. I own about 40. They do lose some charge when stored, but even if I had Powerex's Imedion (low self-discharge) batteries, I'd still top them off before every outing. I'm paranoid. But they're very good batteries.

In terms of recharge time, lithium still takes top honors. The recycle time doesn't increase as much as the battery charge drops (probably a function of lithium's shallow discharge curve compared to NiMh). That said, for obvious reasons, I'm probably not going to use them very often.

[Black Pearl]

I have used noting but Energiser Lithiums in all my Nikon flash gear for years without an issue, a friend uses them in a mix of Canon 550EX and 580EX guns without any issues.

I would question where you bought them and were they genuine?

[William W]

Thanks for the note.

 The batteries (lithium set of four) overheated, not the Flash (per se) overheated > ergo some discharge / recharge cycle was set up between the 4 lithium and the remote battery pack? I don’t know – this is a speculation. But I would expect that Li Batteries would “melt” if one began charging them.

 The Flash’s auto cut out did not initially ‘cut out’, because it was the batteries which were getting hot (rapidly and exponentially once the charging loop began).

(i.e. if you heated up a set of 4 batteries in an oven and plonked them in a 580 MkII it would not initially cut out simply because you had “hot batteries”).

By the time the flash failed the damage was done.

This also is a speculation

 I am aware of the 580MkII auto cut out system NOT working efficiently and subsequently frying three flash heads – two I have seen. These were all rapid fire, in bright ambient, flash as fill (i.e. flash working hard as per your experience). This is fact.

***

I don’t mix battery types – not even the way you have described. I thought again about this for a while before I posted – I do think there are legs in the idea that a charge loop was activated between the battery pack and the Li Batteries: my knowledge of battery maths is not at the level where I can make a statement, but I sniff that is a reasonable line of thought to investigate.

However I’d reckon it would be worthwhile suggesting that the 580MkII did not cut it when it should have – and work on a repair, pro bono, along those lines.

WW

[Manfred M]

Using two different types of batteries, whether they are in the flash itself of in an auxilliary battery pack could indeed be problematic. Part of the issue is the way the batteries are packaged; just because they are packaged in a similar manner, for example AA style does not mean that they output the same voltage.

When you onnect the battery sets in parallel; the battery whose electrochemical makeup has the highest voltage will charge the set with the lower voltage. Lithium-ion (Li-ion) batteries, depending on the specific chemistry that they use run somewhere between 3 and 4.2V per cell. Nickel metal hydride (NiMH) on the other hand are 1.2V per cell. Assuming that thee of your Powerex are connected in series to output 3x1.2V = 3.6V are connected to the Li-ion cells at 3V; the configuration will be charging the Li-ion cells. As you are not using a charger and the batteries are connected directly, the Powerex batteries will use the 0.6V potential to drive additional charge into the Li-ion batteries in the Speedlite. The Li-ion battery when charging is acting like a fairly larger resistor and can get very hot; so the damage you are seeing sounds completely plausible. I use Powerex batteries in my Speedlights and the AA style are rated at 2700 mAH (or 2.7AH) so there is enough storage capacity to create a lot of heat.

Bill is absolutely correct in never mixing battery types, and that is the reason why. It is also the reason that device manufacturers tell you to use fully charged (in the case of disposible batteries, new ones) because a similar issue can occur even when using the same type of batteries.

[Ken MT]

Read Syl Arena "Speedliter's Handbook: Learning to Craft Light with Canon Speedlites". He managed to cook a 580 speedlite with a torture test to check the output with repeat flashes with different batteries (page 217). Sounds similiar to what you did.

[Colin Southern]

There's no problem mixing battery types between the flash and an external battery pack because the external pack outputs 380 bolts straight into the flash high-voltage port ... It's not paralleled with the internal batteries in any way.

You can set a flag to use only the external pack for firing or both - the internal batteries are used to run the electronics regardless.

The overheat works for the flash internals - not the internal batteries.

Off memory, the manual says "give the flash a rest after 20 full power dumps".

Sounds to me like you just worked the batteries too hard and - unfortunately - "they delivered" what was requested, at the expense of destroying themselves. I've never had any catch fire, but I've had them too hot to hold.

Next time ...

- set the flag to only charge from the externals (it makes little difference to recycle times), or ...

- use a a battery eliminator and connect it directly to a 6 volt source, a-la the sljacobs.com black box.

Hope this helps.

[William W]

Thanks Manfred.
But I think my sniffing about a charging loop, was incorrect.
But I still won’t mix batteries.

***

There's no problem mixing battery types between the flash and an external battery pack because the external pack outputs 380 bolts straight into the flash high-voltage port ... It's not paralleled with the internal batteries in any way.

OK. Good. Thanks Colin.
I must start using my 580 flash units again sometime soon.

***

The overheat works for the flash internals - not the internal batteries.

I got that part correct.

I would give a score of about 40% for my answer: very unsatisfactory.
Note to self - 'nuff of this “available light fancy stuff” - I gotta go out and use my canon Flash units more often.

WW

[Colin Southern]

Thanks Manfred.
But I think my sniffing about a charging loop, was incorrect.
But I still won’t mix batteries.

***

Don't mix within a set, but between the two different power sources it doesn't matter as they quickly get out of synch anyway.

OK. Good. Thanks Colin.
I must start using my 580 flash units again sometime soon.

I used to love mine ... Until I got the 600EX-RTs

Note to self - 'nuff of this “available light fancy stuff” - I gotta go out and use my canon Flash units more often.

WW

Natural light sucks!

[Ken MT]

Overheating from overuse of flash with 580 EX 11 from manual

[Colin Southern]

Overheating from overuse of flash with 580 EX 11 from manual

In practice it varies, with the biggest variable being power output.

They definitely have real-world limits though. Probably one of the biggest differences between speedlights and studio heads.

[William W]

Natural light sucks!

That's why you NEED all the bag full the very fast PRIME LENSES . . . to suck-up all the natural light . . .

[Colin Southern]

That's why you NEED all the bag full the very fast PRIME LENSES . . . to suck-up all the natural light . . .

Yep - so after they've sucked up all natural light they can disappear into a black hole!

[RustBeltRaw]

There's no problem mixing battery types between the flash and an external battery pack because the external pack outputs 380 bolts straight into the flash high-voltage port ... It's not paralleled with the internal batteries in any way.

I was skeptical when I first read this, but the CBP-C1 manual includes lots of warnings consistent with a very high-voltage device. The pack's transformer must be really light, because it doesn't feel like there's anything but air inside the outer case.

When you onnect the battery sets in parallel; the battery whose electrochemical makeup has the highest voltage will charge the set with the lower voltage. Lithium-ion (Li-ion) batteries, depending on the specific chemistry that they use run somewhere between 3 and 4.2V per cell. Nickel metal hydride (NiMH) on the other hand are 1.2V per cell. Assuming that thee of your Powerex are connected in series to output 3x1.2V = 3.6V are connected to the Li-ion cells at 3V; the configuration will be charging the Li-ion cells. As you are not using a charger and the batteries are connected directly, the Powerex batteries will use the 0.6V potential to drive additional charge into the Li-ion batteries in the Speedlite. The Li-ion battery when charging is acting like a fairly larger resistor and can get very hot; so the damage you are seeing sounds completely plausible. I use Powerex batteries in my Speedlights and the AA style are rated at 2700 mAH (or 2.7AH) so there is enough storage capacity to create a lot of heat.

Bill is absolutely correct in never mixing battery types, and that is the reason why. It is also the reason that device manufacturers tell you to use fully charged (in the case of disposible batteries, new ones) because a similar issue can occur even when using the same type of batteries.

I've worked with hybrid vehicle battery systems in the past, so I'm aware of all these issues. Wanted to spare the audience a text wall, but as usual, Manfred fears no explanation. But if Colin is correct, then this issue is moot. I hope he's right, because I was pretty sure this was what happened, and it would probably have invalidated the warranty. But now I wonder if Canon will repair the 10-moth-old flash pro bono.

One correction: the data sheet for Energizer Ultimate Lithium batteries lists a nominal voltage of 1.5V. Equal to the full-charge voltage (1.5V), and greater than the nominal voltage (1.2V), of a Maha 2700mAh NiMH. So the charge loop effect would probably have been considerably less severe than your statements indicated. The configuration would have been two parallel series of four NiMH cells at 4.8-6V, and one series of four lithium cells at ~6V. So the charge loop probably would have been the lithiums charging the NiMHs at rate increasing as the batteries discharged.

But again, this is all academic since Colin's probably correct. Regardless, it doesn't look like I screwed up the way I thought I did - I just used the batteries heavily enough to damage the internals before the thermal protection kicked in. Bill, thanks for the first-hand account of similar issues, and Colin, thanks for the manual excerpt. Unfortunately, it looks like things didn't quite proceed as bullet point 2 indicated. Regardless, the flash is in for repair, and I should have a quote soon. In the meantime, I'll contact Canon about warranty coverage.

[Colin Southern]

I was skeptical when I first read this, but the CBP-C1 manual includes lots of warnings consistent with a very high-voltage device. The pack's transformer must be really light, because it doesn't feel like there's anything but air inside the outer case.

It's not so much "transformer" (they don't work with DC) as it is "inverter" (that turns the DC into AC and then additional rectifier circuitry converts it back to DC again, but at a much higher voltage).

But if Colin is correct, then this issue is moot. I hope he's right, because I was pretty sure this was what happened, and it would probably have invalidated the warranty. But now I wonder if Canon will repair the 10-moth-old flash pro bono.

I'd bet my life on this one (I had 4 of the 580EX IIs and 4 of the Canon CP-E4 external voltage accelerators) - we go "waaaay back" together

Regardless, it doesn't look like I screwed up the way I thought I did - I just used the batteries heavily enough to damage the internals before the thermal protection kicked in. Bill, thanks for the first-hand account of similar issues, and Colin, thanks for the manual excerpt. Unfortunately, it looks like things didn't quite proceed as bullet point 2 indicated. Regardless, the flash is in for repair, and I should have a quote soon. In the meantime, I'll contact Canon about warranty coverage.

My guess is you just worked the flash too hard and the batteries were the weak link in the chain. If they fix it under warranty then great, but it really was a user error, not a flash malfunction (sorry!) (unless the flash just plain shorted out the batteries).

[RustBeltRaw]

It's not so much "transformer" (they don't work with DC) as it is "inverter" (that turns the DC into AC and then additional rectifier circuitry converts it back to DC again, but at a much higher voltage).

You're correct. I should have said DC-DC converter. My excuse is that I'm a mechanical engineer.

I'd bet my life on this one (I had 4 of the 580EX IIs and 4 of the Canon CP-E4 external voltage accelerators) - we go "waaaay back" together

"External Voltage Accelerator" sounds way more Buck Rogers than "battery pack." They just don't name them like they used to.

My guess is you just worked the flash too hard and the batteries were the weak link in the chain. If they fix it under warranty then great, but it really was a user error, not a flash malfunction (sorry!) (unless the flash just plain shorted out the batteries).

But the manual you quoted says that the thermal protection should kick in if you go over 20 full-power flashes. Not that Canon's likely to take my side, but it does seem like I operated the flash within the manual's instructions. Regardless, I was definitely pushing the poor thing.

[Manfred M]

My excuse is that I'm a mechanical engineer. .

Me too. I seem to remember a love / hate issue with the mandatory electrical engineering courses we had to take. They gave us the profs that they did not trust to teach the electrical engineering students. At least I came out with a vague idea as to how semiconductors circuits and different types of electric motors work.

But the manual you quoted says that the thermal protection should kick in if you go over 20 full-power flashes. Not that Canon's likely to take my side, but it does seem like I operated the flash within the manual's instructions. Regardless, I was definitely pushing the poor thing.

I strongly suspect that all they monitor is the duty cycle of the electronic components and I would be very surprised if the battery compartment has any temperature monitoring at all. My Nikon SB-900 has a strong tendency to overheat and I can trigger thermal shutdown in less than 20 full-power flashes. I understand this was the main reason that the SB-910 was introduced. I do know some wedding photographers who shoot the SB-900 who have overridden the default cutoff level on the unit and their units feel really hot compared to the way I tend to shoot (hint: I wouldn’t buy a used one from them; I expect that they have severely compromised the life of the flash)

[Colin Southern]

But the manual you quoted says that the thermal protection should kick in if you go over 20 full-power flashes. Not that Canon's likely to take my side, but it does seem like I operated the flash within the manual's instructions. Regardless, I was definitely pushing the poor thing.

Not quite. It's based on temperature, not "number of shots". If you fire twenty CONTINUOUS (as in as fast as the device is physically capable of recycling) - THEN - there will be some components inside that will have heated up due to the high workload and not being able to dissipate that heat in the short time. The batteries are a different kettle of fish though; because of their mass, they're much slower to heat up, but much slower to cool down -- and I suspect that the continuous shooting just kept them heating and heating and heating and heating. So long enough between shots for the flash internal circuitry to cool, but not long enough for the battery heat to dissipate.

It's probably just unfortunate that you just happened to work it in the worst way possible. I've done similar to the point where a set of batteries has gone flat and I've taken them out to change them and though - "woah - these are pretty hot". These days I run 4 flashes in a 4-Square holder, which means each one only operates at 1/4 the power (and heat).

[Colin Southern]

I wouldn’t buy a used one from them; I expect that they have severely compromised the life of the flash)

Out of interest, I read the story of a guy who "took one to the limit" ...

Kevin Attempts to Abuse a Strobe

(This from: Kevin 'Destroyer of Worlds' Horton (khorton@tech.iupui.edu))Just for funsies, I decided to see how much torture I could inflict on the flashlamp and energy storage capacitor from one of those little Kodak cameras. The tube was 1.2" long, in a metalized plastic reflector, with a thin metal backing to hold it in. The capacitor was 120 uf, 330 V. I hooked it up to my inverter (12 V->300 V at high current) and fired 'er up! Pop, pop, pop, pop, pop, pop, pop, (turn up trigger oscillator frequency) popopopopopopopopopopopop! It was firing about 30 or 40 times a second; it appeared as it was constantly on! I turned it down to about 15 flashes a second, and let it run. First thing I noticed was that wonderful scent of melting acrylic. Then, I noticed that the tube was kind of skewed in the reflector. The plastic was in full smoke-mode by this point. Still, the tube kept firing! (Let's see: 5 W-s times 15 flashes per second is 75 W average power, not bad for an itty bitty tube --- sam).
I left it on a bit more, and the plastic really started the smoke-signals! I noticed that one electrode was glowing cherry red. Even after all this torture, it kept going! The smoke was getting too much, so I hit the 'off' on my inverter. A few more gouts of smoke, and the little fire I created was extinguished. I let it cool down and then I examined the damage. The reflector was totaled; the tube had all but melted clean through. When I touched it, the little metal plate popped off.
On closer examination, the tube appeared to be in good shape. I couldn't see any visible damage to either the electrodes, or the glass seals. A quick test reveals that the tube still functions. As a side note, the storage capacitor got quite hot; probably around 35 degrees C. All in all, an interesting test, I must say. The next will involve connecting up a normal NE2 neon bulb and observing the results of high voltage and high current on it. I suspect it will be quite spectacular, so I'm taking precautions - It will be performed in a proper enclosure, so if the neon decides to really go 'pop', it won't do any damage.