I've recently purchased a Canon 430EX II to use with my 550D and it's great but I'm having battery issues.

I've been trying to use 2× 800mAh Ni-Cd and 2× 2500 mAh Ni-Mh (all rechargeables, the 800mAh being a few years old) but I'm finding that if I charge the batteries the day before I intend to use them then flash won't fire (even the test flash).

Now I'm aware that the 800mAh batteries are probably too weak and worn out for usage in an external flash. But I don't know whether to buy a new charger and four high powered rechargeables or just keep buying named brand disposable batteries.


3 Answers 3


Not only do you need new batteries, but what you want is low self-discharge NiMHs. Like the name says, they have a better not-in-use retention of charge, reducing frustrations like this. They generally have lower capacity than "regular" NiMHs, but unless you're planning to recharge and then use them up immediately, it's worth it.

The common brand name here is Sanyo Eneloop (I think they were first to market), but there's now lots of others as well.

Also see (and vote up!) Mike's answer to this question. You shouldn't mix battery types like that. (In fact, it's best to use a matched set that you always use and charge together.) I highly recommend 8 new low-self-discharge NiMHs, so you can have one set in use and another ready to go.

  • \$\begingroup\$ +1, Eneloops are amazing. I charge them, stuff the flashes back in the bag, and they're still ready to shoot when I take them out after two weeks. \$\endgroup\$
    – che
    Commented Feb 1, 2011 at 22:46
  • \$\begingroup\$ eneloops. Or one of the rebranded eneloops (I found at Costco a pack of Duracell Rachargeable Precharged batteries. The ones made in Japan are rebranded eneloops and have a white ring around the "+" terminal) \$\endgroup\$
    – ysap
    Commented Feb 1, 2011 at 23:19
  • \$\begingroup\$ That explains why my normal rechargeable batteries don't work well. Thanks for the post! \$\endgroup\$ Commented Sep 28, 2015 at 19:00

One other thing - don't mix your batteries with different specs. In your case, mixing 2500mAh batteries with 800mAh batteries will be causing you problems.

  • \$\begingroup\$ Oh wow, good catch. I glossed over that in the question. Absolutely! \$\endgroup\$
    – mattdm
    Commented Feb 2, 2011 at 3:39

Get new rechargeables. Disposable batteries (alkalines) have much higher internal resistance, and they'll bring the recycling speed way down.(Okay, maybe not as far down as flat batteries, but slow nonetheless.) Disposable lithiums will cost an arm and two legs over time. They're great for something you drag out of the closet at Christmas for a half-dozen snaps and put away till next year, but if you use the flash with any regularity at all, they'll be the most expensive option.

NiCds tend to perform better when new (they have a very low internal resistance, resulting in recycling currents that can actually harm some older flashes) but they have horrible lifetimes unless you are meticulous about charge/discharge cycles. NiMHs perform only slightly less well when new, and will both last longer per charge and last longer overall with less worry about things like charge memory. Lithiums are also an option, but your flash really needs to be built to accept them -- they have a high enough cell voltage and a low enough internal resistance to quickly fry a flash.

The upshot? New NiMHs will probably be your best bet.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.