More 600EX-RT/Battery questions...fun!

[nuncle]

Greetings all!

I've seen several discussions about batteries and the flash, but I'm just trying to get the "definitive" answer 🙂

I've got two 600EX-RT's. The first one died on me at Christmas last year. While shooting, I discovered that the batteries became hot...really hot. The next time I tried to turn on the flash...nothing. Brand new batteries did nothing.

I had some extra money at the time and my flash was almost 2 years old so I bought a new 600 in January. While shooting with it about a month ago, the same thing happened. The batteries got so hot that, after I took them out and put them into my pants pocket I had to take them out because they were burning my leg!

That flash was still under warranty, so I sent it in and it's fixed now.

I have always used non-rechargable batteries...and I've used the Duracel Ultimate, for the most part...or the Eveready version. Don't remember the name, but I've always bought the "strongest, longest-lasting" type of whichever brand, on the theory that "The stronger the bettery, the longer it'll last".

Are rechargeable batteries better for the 600EX-RT? Are they worse? What's the Straight Dope? 🙂

[TCampbell]

I use rechargeable Eneloop batteries.

Eneloops are low-self-discharge.  A regularly rechargeable battery will drain merely sitting unused at a fairly quick rate... quickly enough that a few weeks after charging it will have lost quite a bit of power.  A low-self-discharge battery has a shelf like almost like a non-reusable battery... a year after charging they still have about 90% of their charge.

That means if you charge up some batteries to be prepared for the next time you need them...  you don't have to worry that they'll be very low or drained the next time you need them.

But I am a bit worried about these batteries becoming "hot".   When batteries are either charging or draining, they'll get a little "warm" but generally not "hot".  Usually "hot" means you're draining the batteries very quickly.  Were you running the flash hard?   If you _do_ need to run the lights hard (rapid fire and high power levels) you can split the load across multple flashes (there are mounts that will let you cluster 3 or even 6 flashes on one stand.)

[RobertTheFat]

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@TCampbell wrote:

I use rechargeable Eneloop batteries.

Eneloops are low-self-discharge.  A regularly rechargeable battery will drain merely sitting unused at a fairly quick rate... quickly enough that a few weeks after charging it will have lost quite a bit of power.  A low-self-discharge battery has a shelf like almost like a non-reusable battery... a year after charging they still have about 90% of their charge.

That means if you charge up some batteries to be prepared for the next time you need them...  you don't have to worry that they'll be very low or drained the next time you need them.

I too use Eneloops - the black professional series. My experience so far suggests that their low-self-discharge characteristics are somewhat exaggerated: they appear to lose power on the shelf at about the same rate as the "Enercells" sold by Radio Shack. But the Eneloops have been very reliable.

But I am a bit worried about these batteries becoming "hot".   When batteries are either charging or draining, they'll get a little "warm" but generally not "hot".  Usually "hot" means you're draining the batteries very quickly.  Were you running the flash hard?   If you _do_ need to run the lights hard (rapid fire and high power levels) you can split the load across multple flashes (there are mounts that will let you cluster 3 or even 6 flashes on one stand.)

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All modern Canon speedlites are supposed to automatically shut down for a few minutes if the flashtube starts to overheat. (I've had it happen to me.)

But batteries overheating are a different matter. A battery overheats when the current flowing through it is too high. What may be happening is that as the batteries deplete, they may be unable to maintain their rated voltage (usually 1.5 volts each for non-rechargeables). The light, which expects to consume a given amount of power (watts) to recharge itself, may be forcing the batteries to deliver that power by increasing their current flow. (Remember that watts = volts x amps.) The batteries should be able to resist that demand, forcing the light to recharge more slowly (or not at all). But if they can't, they will overheat.

Fill disclosure: I'm not an electrical engineer. So the first person who identifies himself as one should probably be listened to instead of me.

[nuncle]

Hi Bob!

That sounds pretty close to right, actually:)

The recycle time absolutely increases a ton after I've used the flash for a while. Later on in the day (Like during the wedding reception after the toast, during the dancing), it's pretty much guarenteed that I take a shot or two without the flash because it didn't fire when it was supposed to, because it was still recycling.

     Now, that does only seem to happen when I'm using the flash relatively hard. Perhaps taking 5-6 pics a minute, on average. Not for an hour continuesly of course, but imagine taking pics while the wedding couple dances and all the fun that's happening and you get the idea...

     Would rechargable batteries make any difference with this, do you think? Logically, it doesn't seem like it would since they must operate the same way as alkaline..?

     And what about using a battery pack? Something like this:

http://www.amazon.com/Canon-CP-E4-Compact-Battery-Pack/dp/B000NSJ4Q0/ref=sr_1_1?ie=UTF8&qid=14056950...

Does it really make that much of a difference? This is a bit pricey and the newest review for it seems to be 2010, so that doesn't seem like a big seller, you know? 😛

[TCampbell]

Rechargable batteries cycle noticeably faster than alkalines.    

If you were to graph a power-depletion curve for the flash, showing the voltage output as the remaining milliamp capacity drains, you'd notice that an alkaline battery's voltage keeps gradually dropping until it runs out of power.  Rechargeables are different... they tend to consistently put out the same voltage... but just as they get to the end of their supply of power then voltage suddenly drops quickly.

When you use an external battery pack, the recycle times are faster in addition to being able to shoot longer before needing to change the batteries.

[RobertTheFat]

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@nuncle wrote:

Hi Bob!

That sounds pretty close to right, actually:)

The recycle time absolutely increases a ton after I've used the flash for a while. Later on in the day (Like during the wedding reception after the toast, during the dancing), it's pretty much guarenteed that I take a shot or two without the flash because it didn't fire when it was supposed to, because it was still recycling.

     Now, that does only seem to happen when I'm using the flash relatively hard. Perhaps taking 5-6 pics a minute, on average. Not for an hour continuesly of course, but imagine taking pics while the wedding couple dances and all the fun that's happening and you get the idea...

     Would rechargable batteries make any difference with this, do you think? Logically, it doesn't seem like it would since they must operate the same way as alkaline..?

     And what about using a battery pack? Something like this:

http://www.amazon.com/Canon-CP-E4-Compact-Battery-Pack/dp/B000NSJ4Q0/ref=sr_1_1?ie=UTF8&qid=14056950...

Does it really make that much of a difference? This is a bit pricey and the newest review for it seems to be 2010, so that doesn't seem like a big seller, you know? 😛

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I have two of those. I used to use them for all major events, but rarely anymore. The plastic tabs that hold the batteries in place are annoyingly flimsy and tend to break off. And since each one is just eight rechargeable NiMH AAs with some extra circuitry, it doesn't improve your recycle time very much. But any battery pack will at least keep the recycle time from deteriorating as much while the batteries are running down.

What I use for events now is one of the Godox lithium battery packs. (B&H sells them under the "Bolt" brand name.) On the one I have, the battery itself is detachable. So you can have a spare, and with a second charger you can charge both at once. It has two outlets, so you can power two cameras. I love that feature, becausse I almost always use two cameras at events, so that I don't have to change lenses.

A battery pack like my Bolt does decrease the recycle time, but that's a two-edged sword. When you fire the flash more often, it heats up faster, even though the battery doesn't. You can reach a point at which either the flash knows enough to stop and cool off or it burns out. Recent Canon speedlites are pretty good about knowing when to stop, but the online literature is replete with horror stories. So the more powerful battery pack you have, the more careful you need to be. Even if the worst doesn't happen, it's damned embarrassing at an inauguration or awards ceremony to have the flash take a 12-minute timeout while there are people on the stage waiting to be photographed. I sometimes try to have a third flash available to guard against that eventuality.

Even with a battery pack, you still need four batteries in the flash unit to control its circuitry. For that I always use high-quality rechargeables and wouldn't consider anything else.

[nuncle]

Thanks for all your help, everyone! 😄

I think that rechargeble batteries are definitely in my future...you get hit over the head enough times and eventually it sinks in.. 🙂

[Skirball]

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@nuncle wrote:

Are rechargeable batteries better for the 600EX-RT? Are they worse? What's the Straight Dope? 🙂

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Yes, recharageables are better.  They are quicker to recycle, hold more flashes, generate less heat, and cost less (in the long run) than alkaline.  Not to mention you're not tossing batteries in a land fill.  It amazes me how many photographers regularly use alkaline.

Now, that said: there have been a few reports of issues with using rechargeables in the 600exRT.  THere's a few threads on here you might want to read.  In the manual it even says to use alkaline.  The issue is sporadic, otherwise there would be a lot more complaints about it, and Canon would have been forced to fix the issue instead of just put a warning in that the flash needs alkaline.  It's asanine, there is absolutely no reason, from an engineering standpoint, of why the flash would need alkaline.  I'm not sure what happened, but Canon f-d up.  It's the first issue I've ever heard about flashes having a problem with rechargeables.

As to which brand, there's only one: Eneloops. The white ones, not the XX (I can discuss why if you want).  Panasonic bought out Sanyo, so make sure the package says Panasonic so you're getting the latest.  They did a minor upgrade (4th generation), stating it has more recharges than before (2100 vs 1500).  Not sure if it makes a difference, but if you're going to buy, might as well get the latest.  Also, get a good charger, like a Maha.

[TCampbell]

On the charging note... I bought the Maha, but it was dead on arrival and returned. I opted for a different charger (I don't recall which one, but I'm not nearby to be able to check it.)

In any case, there are a number of 3rd party chargers that allow you to set the charging rate. Slow charging is always better (less heat generated) if you have the time to let it slow charge.

[nuncle]

I'm definitely going to look into the rechargeable option, I think 🙂 How long does a slow charge vs a fast charge take, approximately? Maybe I'll head down to Best Buy today and see what they have. I'm not assured of anything online getting here in time for a Tuesday morning flight, unless I pay more in shipping than the item costs... 😛