Higher capacity batteries in strobe

[Chris Ross]

The rest of the circuit is what sets the current flow so has an impact on the heat generated. If the battery is 100 mOhm, the entire circuit is effectively 600mOhm, so the rest of the circuit is 5x the resistance of the battery. The point is that if other batteries are 120 mOhm and the eneloops are 100 mOhm, then the difference in heat buildup should be relatively small as the biggest impact on current flow for any particular strobe is the coil's effective resistance. I say effective resistance as the measured resistance in DC is very low, the impedance of the coil is what limits current flow.

 

[Interceptor121]

I think you are going on a tangent here. The strobe is a switching circuit with flash tube inside of course as the tube is what discharges the energy provided by the batteries it gets hot together with any passive element in the circuit but this is the same Eneloops or not so irrelevant to the battery discussion however eneloop batteries with lower internal resistance will provide higher currents than other NiMH or same current at higher voltage and therefore develop more heat than other batteries. What the strobe does remains roughly the same as the energy that goes in is the same and is determined by the size of the capacitor. With a lower current battery it will take longer to charge and the battery will generate less heat the strobe will charge and is discharge the same with an eneloop the strobe will charge faster and the batteries will get hot. How hot they remain and if they pop depends on the ability to dissipate heat of the battery compartment
Like wise the heat that builds in the circuit has to go somewhere or it may burn consider that the capacitor discharges predominantly in the bulb
If you want to have some fun just discharge some batteries in your strobe and then see how hot they are when you take them out
If eneloops were running cooler than others manufacturers would not put disclaimers on their strobe wouldn’t they??

 

[Interceptor121]

There is a guy that has done tests with flashgun fundamentally the declared battery capacity using the IEC standard of 0.2C means 400mA for a 2000 mAh battery that is a very different situation of charging a strobe where you can drain several amperes. At some point a higher nominal charge battery drops below a low self discharge
Interestingly Panasonic recommendation eneloop Pro for flashguns and not the standard eneloop. In terms of life a pro battery is rated at 500 cycles while a lower charge at 2000. So if you cycles two seta of eneloop for your strobes I n 1000 dives they will be dead. In practical terms 3 years should be the time you change them and this is pretty good value. I have to say I have also kept non LSD batteries that long but eventually they failed

 

[cerich]

I think the Nikon recall was because of explosions on land, underwater it should be totally unconsequential.
Bill

yeah, not at all.

when they go they are loud to the damage hearing level and if close to the body can and have left people with wounds and even lose of digits

 

[bvanant]

From Nikon:
Incidents/Injuries: Nikon has received one report of the lens propelling from the Speedlight flash. No injuries were reported. Nikon also is aware of 12 other incidents which occurred outside the United States, but no injuries have been reported.
I am quite skeptical that it could blow off a finger underwater. Is there any evidence that this did actually hurt someone?
Bill