I have a MAHA MH-C9000 Advanced Battery Charger sold by thomasdistributing dot com, fantastic chargers they bring dead batteries to life, independent channels and all the works. For batteries I use Sanyo Eneloop 2000 mAh for AA and 800 mAh for AAA.

I'll second jonnyapple's recommendation of the La Crosse charger. I have the BC-700 and have been really happy with it. Biggest advantage is that it is a four channel charger so each battery is charged independently of the others. This comes in really handy when recharging the 5 batteries for the flashgun. Recharge four and then recharge the fifth. No needing another dead battery to be able to charge an odd number.

Thanks Sideways, thanks Jonny and everyone else who has contributed. I have found a company on Amazon selling 40 2000mAh Eneloops for £60, seems to be the best price I can find, also I currently have an 8 AA charger so might buy another to speed up the process of charging them all after a big shoot. Some Korean company is selling a 20/50/100 AA charger on eBay, that would certainly finish the job in double quick time!

Thanks for all your help.

Another good charger is the La Crosse BC-700 (edit: I guess I've got the BC-900). I've been using mine for a couple of years and although the adapter connection has been kind of spotty for a couple of months, the charger has been great (I need to open it up and solder that connection—this is not unusual for anything I leave out where my two young boys can play with it).

I kind of feel like I've mentioned it before on this thread but I'm too lazy to check.

Most of the info has been covered here already but I've spent a bit of time experimenting with rechargeables etc for high power flashlights so i'd like to offer this as a quick summary

For fastest recharge / maximum flashes in flashguns etc (high drain equipment) use high power NiMH cells.They can hold the most energy.
But - high power NiMH discharge quickly by themselves when sat on a shelf - so to get their full capacity charge them the night before you use them. If you leave them in your bag for 3 months they'll probably come out empty - don't use these for an emergency light you leave in your car :-)

As has already been said, rechargeables only give 1.2volts compared to 1.5 volts for primary cells, but the voltage of any battery drops the more current you draw from it. This effect is much more severe in primary batteries.
End result, rechargeables are better at driving anything that needs a lot of current like a flashgun or when you push transmit on your walkie-talkie.

The new "low self discharge" NiMH cells that have appeared on the market in the last year or so don't have as much capacity (around 2000mAH) as the standard NiMH cells but are still great at driving high drain equipment. Their advantage is that they keep their charge much better . They are sold "ready to use" from the packet and will still have ~85% of a full charge after sitting for 12 months. I use these for the spares in my kit so that I don't have to cycle them every week to keep them full.

I've used Duracell brand and "GePe ReCyko" brand in the UK and both are good. Both makers produce a range of batteries so check you're selecting the variety you want. Eneloops are a best seller worldwide - they wouldn't be if they weren't a decent product.

I suggest buying from name brands because they have more reputation to lose so quality control is likely to be good.

For low consumption devices and kit that needs the full 1.5 volts, I think that Energiser primary (i.e. disposable) lithium batteries - the silver and blue ones - are expensive but worth it. They have much higher capacity than normal alkaline cells and a massive shelf life. These are excellent in GPS receivers and the like because you don't have to replace or recharge them often and the long life means you rarely need to carry spares. They also keep working in the cold while alkaline cells in particular do not.

The best charger you can buy for AA and AAA cells is the Powerex / Maha Wizard One charger. Expensive but it charges from one to four cells individually controlled by computer - lets you discharge each cell to empty, fast or slow charge it to full, measures the capacity of each cell so you can match them into sets, etc etc. This keeps your cells in great condition.

My last point is about care and maintenance -

Memory effect is more myth than real and doesn't apply to NiMH or Lithium rechargeables so there's no reason not to recharge a half used set of cells.

What kills rechargeable batteries is running the pack absolutely empty. Whatever it says on the label, each cell will have a different capacity - sometime very different. When you run a set of batteries right down, one of them will reach empty first. The remaining cells then continue to push current through the empty cell "over discharging" it. This causes the weak cell to heat up and heat eventually this causes the cell to fail. The answer is to swap out the batteries as soon as you notice any real drop in performance as this is an indicator that the weakest cell has reached empty. This applies to cordless power tools even more than cells used in photography.

A great advantage of the wizard one charger is that you can see the real capacity of each cell so you can match your rechargeables into sets that will all empty at about the same time.

The second common way of killing NiMH cells is to use a fast charger that doesn't turn off when the cell is full. As soon as a cell is full, the extra energy has nowhere to go so starts heating up the cell. Regular overcharging kills cells so I recommend buying a good charger otherwise the life of your cells will be much less than the lifetime promised by the manufacturer.

Fortunately the lithium rechargeable packs used in cameras, laptops, etc include electronic circuits to protect them from overcharging, over discharge and the other abuse that can cause them to fail dramatically. No special advise is needed except to note that that a lithium pack can be damaged if left in a discharged condition for a long time so best to recharge after use, and to remind you that lithium is not something to be messed with so stick to the approved charger unless you know exactly what you're doing :-)

Hope this helps and all the best.

@skinbrit - my mistake, indeed PW flex is using AA (thought it's AAA), however mini is using CR type battery. yup, by regular I mean 2000 mAh

I use the 2000mAh ones, SkintBrit. I haven't used the 2.5Ah ones, but I'm sure they're great, too. You're the one who knows whether a 25% increase in capacity is worth double the money to you.

Bland said:
I use the Sanyo Eneloop as well and they've been great. They take hours to recharge but no biggie as you can get a 1,000 shots per charge. I think I paid around $30 for 4 of them with charger.

Thanks Bland, unfortunately I need about 40 of them to power my various bits of kit, so it's not going to be a cheap purchase. This is why I was asking for anyone's personal experience on whether it is worth paying the extra for the 2500 mAh verities? Charging time is not a deal breaker for me, as I always carry spares on a shoot, and so can charge at my leisure when I get back.

adamz said:
I use a lot of the regular ones and don't have any problems with them whatsover; as for PW neither minittl or flex accepts AA

By regular ones you mean 2000 mAh ? Why do you say PW Mini TT1's & Flex TT5's don't work with AA's? That's all they take?

Thanks for the info Adam, I'll besure and pick one up this weekend!

@bland - I use eneloops and my app charge time is max 15min, I use sony fast charger

@skintbrit - I use a lot of the regular ones and don't have any problems with them whatsover; as for PW neither minittl or flex accepts AA

I use the Sanyo Eneloop as well and they've been great. They take hours to recharge but no biggie as you can get a 1,000 shots per charge. I think I paid around $30 for 4 of them with charger.

O.K. I'm going to buy a load of eneloops. They seem to come in 2000 and 2500 mAh versions. The 2500 ones are about twice the price, any suggestions for use in my SB900's and Pocket Wizards?

Thanks guys!

The memory effect may be a myth about NiCads (not to be confused with NiMhs), but storing either for extended periods of time flat can lead to problems. Once any rechargeable cell drops below its critical voltage damage can occur. This is most pronounced with Lithium and Lead batteries, bit can occur with Nickel as well.

This damage during voltage drop below critical is much more likely when storing cells in a device, or storing a battery (to be pedantic a battery is multiple cells connected together. AA and AAA and C and D are CELLS, 9Vs are batteries), as the cells with a lower voltage will tend to parasitically charge off their higher voltage neighbors. This is also why "performance" packs are created from "matched cells" meaning all the cells have had their discharge curve measured and only cells with similar curves are used together.

Lithium non-rechargable cells have all the strengths of Alkaline (high voltage) and none of the weaknesses (they are light weight and have a low internal resistance). This is why they are sold for high powered devices. Unfortunately they are expensive.

Also, there is a whole spectrum of chargers from dumb to smart with everything in between.

At one end is a dumb charger which can only trickle charge and pays no attention to the cell's voltage, temp, or condition. This type of charger is perfectly safe so long as you don't charge at a rate much more than 1/10th C (where C = capacity in amp hours (in other words a 2250mah AA should safely take a 225ma charge indefinitely, put much more current than that into it and it needs monitored.). They take overnight to charge.

At the other end is the smartest of chargers which constantly monitors cell voltage and temp, and dynamically adjusts the current being fed to the battery to charge as quick as possible (or as slow if you choose) without causing damage. These chargers can easily be $100.

In the middle is the wasteland of dangerous chargers. This includes most everything sold at Best Buy, grocery stores, Target, etc.
Pseudo-smart chargers tend to do a quick voltage check to make sure the cell isn't below critical, then dump as much power into them as you paid for. The Energizer brand chargers are all this type. Most have a fan pretending to cool the batteries in an attempt to compensate for their lack of proper monitoring circuits. At least the Energizer ones will refuse to charge batteries which are marginal, the GE branded pseudo-smart chargers will happily pump 8 amps into a AA regardless of the cell's condition.

SkintBrit said:
So let me get my head round all this advise.......rechargeables are actually better in high drain items like flash guns than alkaline's. Non rechargeable lithium batteries are good because they have a long shelf life and so do eneloops, and lower power rechargeables are often better than high power ones because they hold their charge for longer and the reduction in amperage doesn't seem to make much difference in practice ? Oh boy, I think I need to lie down :-)

One thing I don't think has been mentioned is whether rechargeables should be stored charged or flat, and if NiMHi have memory effect (do they benefit from a full discharge before charging)?

Supposedly Eneloops have no memory effect.

I wouldn't know, I'm expecting my first set in a couple days.

I have used many and found the best to be the Sony CycleEnergy NI-MH 2000mHa.
The worst has to be the Energizer 2450mHa which I find a total waste of money.

The memory effect is (mostly) mythical, skintbrit, and certainly not applicable to the chemistry of common AA batteries today:
http://en.wikipedia.org/wiki/Memory_effect

I've had great luck with eneloops and other brands' low self-discharge batteries.

So let me get my head round all this advise.......rechargeables are actually better in high drain items like flash guns than alkaline's. Non rechargeable lithium batteries are good because they have a long shelf life and so do eneloops, and lower power rechargeables are often better than high power ones because they hold their charge for longer and the reduction in amperage doesn't seem to make much difference in practice ? Oh boy, I think I need to lie down :-)

One thing I don't think has been mentioned is whether rechargeables should be stored charged or flat, and if NiMHi have memory effect (do they benefit from a full discharge before charging)?

pcraigs said:
I would stay away from Energizer they use keep dying(refuse to charge)

Happened to me the other day. I guess I should have read this thread sooner. >.<

Duracell is what I use and never have had a problem. I can often do a 8-12 shoots on one charge. On a tangent I discovered that Duracell makes batteries for P&Ses and bottom level DSLR'S... Who woulda thought

JorPet said:
@Dormant, that fifth battery is the "quick recycle" battery per Nikon's documentation. It simply allows the flash to recycle much faster, as in instantaneously in most cases. I leave it on all the time as I can then shoot as fast as I chose with the flash without ever having to wait for it to recycle.

Thanks for the info. I may need to use that some time.

Still using all my original Eneloops (some are 3-4 years old) and now have about 30 Duracell rechargeables as well. Have never had a single issue with any of them. Use them in everything from flash and battery grips to flashlights, keyboards, mice and controllers for the WII and XBox. No issues in anything they go into and they last much longer than standard alkaline batteries.

As for the Nikon flashes, they specifically recommend that you use rechargeable NiMh batteries and warn away from Alkaline. That was the primary reason that I first went out and got rechargeables.

@Dormant, that fifth battery is the "quick recycle" battery per Nikon's documentation. It simply allows the flash to recycle much faster, as in instantaneously in most cases. I leave it on all the time as I can then shoot as fast as I chose with the flash without ever having to wait for it to recycle.

Has anybody used the Rayovac Platinum 1.2v 2100mAh rechargables? I've been using Energizer 2000mAh 1.2v pre-charged hybrid batteries with no issues, but recently decided to give the Rayovac's a shot. I've never seen them before now. Obviously Eneloop's are the way to go(yet hard to find in a pinch), but are there any decent alternatives?

I'm using the Rayovac's in my SB-900 and they seem to recycle faster than the Energizer's.

dormant said:
Four 1.5V batteries in series give 6V total.
Five 1.2V batteries in series give 6V total.

Just to make this confusing:

Alkalines have a high internal resistance, which is why they are poor at feeding high-amperage loads like flashes. As one should recall resistive losses are proportional to amperage. So the high internal resistance leads to voltage drop under load.

Nickle-chemistry (both cadmium and metal hydride) batteries have a very low internal resistance, it is why they are preferred over alkalines for high load devices.

So while an alkaline battery may have a 1.5v unloaded voltage and a NiMh have have a 1.2v unloaded voltage, put under similar load the alkaline may drop to 1.0v while the NiMh stays at 1.2v.

dormant said:
Is that why my SB-600 has a strange add-on single battery compartment? For using rechargeables?

.

It will fine with only 4 NiMH batteries but will recyle faster with 5

rbid said:
Take notice that AA rechargeable batteries usually have a different voltage than the traditional AA batteries... (1.5 on the non-rechargeable vs. 1.2 on the rechargeable ones).

Is that why my SB-600 has a strange add-on single battery compartment? For using rechargeables?

Four 1.5V batteries in series give 6V total.
Five 1.2V batteries in series give 6V total.