How low is too low volts for Nikon FG?

[j-dogg]

1.25v on both batteries = 2.5v, the lights come on and immediately shut off, does this thing need 3v for it to work? It locks up, M90 or B will free it. Compartment is clean. Batteries are clean.

 

[BobD]

does this thing need 3v for it to work?

Evidently.

I would consider a 1.5v battery reading at 1.25v to be about shot, but that's just me.

 

[j-dogg]

I haven't shot one of these in a while my weapon of choice is Photomic F and I'm used to fully mechanical, I haven't been behind the wheel of an FG since college and everything else I shoot takens either a specialized battery or AA/AAA

 

[AgX]

Establishing the capacity of a battery by just metering the open circuit voltage is no good approach. (Sometimes I do so to, but then I know how to evaluate the readings.)
This is why good battery testers put an apt load on the battery at testing. (Well there are hardly good testers on the market...)

 

[shutterfinger]

A 1.5 volt battery will read 1.55V to 1.56V on a digital volt meter when new. By the time the battery reads 1.5V it is questionable if it will operate a camera and by the time it reads 1.49V it will not operate a camera.

 

[j-dogg]

I didn't think these were that sensitive to voltage, but I've been wrong about things before, I'll replace them. Thanks guys.

 

[AgX]

A lot of compact cameras have a problem with a voltage as low as 1.2V., that is why NiCads are advisd not to be used. But a T90 for instance can take them.

 

[shutterfinger]

Two factors are in play, voltage and current. NiCad's have a lower voltage but provide ample current until they drop below 1.2V. Carbon and alkaline batteries do not provide adequate current once they drop to 1.49V.

 

[AgX]

By the time the battery reads 1.5V it is questionable if it will operate a camera and by the time it reads 1.49V it will not operate a camera.

Carbon and alkaline batteries do not provide adequate current once they drop to 1.49V.

ALL cells show a rapid fall of voltage at the begin, before the fall slows down. For carbon cells this fall rather goes on, to lesser extent at Alkaline cells and NiMh cells even form a plateau at about 1.3 Volt.

 

[reddesert]

The FG is using two button cells, they cannot provide any useful current once they read 1.3 V or maybe even 1.4 V.

Nicad AA's that read 1.2 V are a completely different thing because they can provide useful current at that voltage. Just checking the voltage is not enough. Most newer digital multimeters have a battery test mode that effectively tells you the current a "1.5V" cell like AA or AAA is delivering, which makes it easy to weed out the ones that are dead but still read "1.45V" on the volts mode.

 

[spark]

Several years ago I purchased a ZTS Pulse Load battery tester because of all the stuff I had that relied on battery power. It was expensive (to me) but has paid for itself.
As others have stated, once a button cell (alkaline or silver-oxide) drops to 1.3 or 1.4 volts open circuit (unloaded), it is dead for most purposes.

 

[Chan Tran]

1.25v on both batteries = 2.5v, the lights come on and immediately shut off, does this thing need 3v for it to work? It locks up, M90 or B will free it. Compartment is clean. Batteries are clean.

2.5V should keep the FG working but... your 2 batteries measured at 1.25V without a load won't provide 2.5V when the FG is drawing current.
As someone already said testing battery without load is not a good way but I do test them that way all the time and for the silver oxide or alkaline batteries used in the FG any reading without load less than 1.5V the battery is considered dead.

 

[Chan Tran]

I didn't think these were that sensitive to voltage, but I've been wrong about things before, I'll replace them. Thanks guys.

The FG isn't sensitive to voltage but expecting your two dead batteries to keep it working is unreasonable.

 

[GarageBoy]

Put in new batteries.... Half the issues with cameras is people using depleted or just plain old batteries (old batteries may show enough voltage, but put some load on them, and they drop hard) - stop being cheap over <$5

 

[gone]

While you're buying batteries (you can get about a million of them for $10 on eBay) buy yourself a voltage tester at Harbor Freight for $8. They last many years on their original battery, and I no longer have to wonder about voltage anymore, I know exactly what the batteries have in them. It's a tool no photographer should be w/o if they shoot cameras that require batteries.

FG's need fully charged batteries to work. I've owned many of them, and always went w/ fresh batteries when things didn't work right. When that particular camera stops working though even w/ fresh batteries (unless the mirror has become stuck up due to sticky foam), they generally stay broken.