> Date: Fri, 26 Oct 2001 16:01:52 -0400 > From: Bob Sull <[EMAIL PROTECTED]> > Subject: Re: EOS Re: NiMh batteries in flash? > > According to the 550EX manual, > (2) Size AA Nicad KR15/51 batteries x4"
Right. As does almost any other flash unit. Rechargeables should be fine, the typical circuitry of flash devices will digest them easily in 99% of all cases. > Alkaline cells are 1.5 VDC and Nicad cells are 1.2VDC. That only ounts for fresh batteries without load. alkaline cells under load drop fast well below 1.2 Volts. NiCd cells on the other hand hold their voltage very stable. > NiMH cells are also 1.2VDC. Their makeup is somewhat > different than Nicads. The differences allow higher > capacities than Nicad. A high capacity Nicad > might be around 1000mAH. NiMH cells are now up to 1600mAH > in an AA size cell. Make that 1800 mAh... yes, they are different. The performance under low temperatures is better with NiCd, NiCd has lower internal resistance and can deliver higher amps, NiCd has less self decharging. Unless you need the higher capacity, NiCd is the way to go. But make sure you use a dedicated microcontroller charger along with it. Wrong charging is the main cause for premature exitus on NiCd cells. > Unless specifically stated by a product's manufacturer, they are > interchangeable as long as the entire battery of cells is changed. > (A battery is made up of a number of cells. Do not mix Nicads > and NiMH in a battery, and do not mix NiMH cells of different > capacities.) And only use cells at the same charge level, don't mix fully and half charged cells. This might else lead to polarity inversion in the weakest cell, which will definitely kill it. > I have been using NiMH in my 550EX since I got it in May, 2001, > and in my 540EZ for the past five or six years. No problems > with either flash. I am using rechargeables in all my flashes for more than twenty years now. There is only one way to kill a flash: Fire as fast as he recycles for hours without pause. Shoe mount flashes are designed to operate with occasional pauses in order to cool off a little. -- Michael Quack <[EMAIL PROTECTED]> * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
