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delft
05-27-2008, 08:04
After having found an A11 for my XA, I wonder if it can stand using rechargeable batteries. Long time ago, it was said that the higher currents these batteries can supply could destroy your flash / strobe.

Greetings,
Dirk

Bill K.
05-27-2008, 09:35
The amount of current depends on the resistance of the device being powered. The resistance of your flash is constant (more or less) and will not draw more current at the same voltage.

I have an A11 flash & did try a rechargable battery in it. It would not cycle (the light did not come on). I suspect this was because the Voltage was at 1.2 or 1.3 and the flash needs 1.5 Volts. Using a single Alkaline AA cell, it worked well.

I hope this helps.

Regards,

Bill K.

delft
05-27-2008, 09:45
Thanks Bill,
This sure helps, as I can now have confidence that I will not fry my flash using rechargeables. I thought rechargeables had lower internal resistance than alkalines, hence greater total current.

Greetings,
Dirk

caperunner
07-08-2008, 17:17
I am having fun today!
NiCad NiMH rechargeable batteries do have a lower voltage than the bog standard alkaline cells.

In a flash unit the circuit used to charge the discharge capacitor is known as a convertor circuit. This is used to chop up the d.c voltage of the battery (squeal noise) then is put through a voltage doubler or tripler to charge the capacitor used to fire the xenon strobe light.

The battery voltage is quite critical for getting the convertor to run properly as you have experienced with rechargeables.

Now that I have you completely confused I have seen it mentioned that some cameras will fry their electronics if NiCad/NiMH batteries are used.

The low internal resistence of these batteries allow larger currents to flow and the resistive components of the camera circuits will burn or blow as a result.
May apply to digi cams too but I use NiMH in mine where they are allowed. Need them in some cams, battery drain is sometimes rather heavy.