Battery drain in unplugged charger? (Page 5): I have Canons also, leave my batteries in their chargers in my bag - sometimes for a month or two. They are still ready to go when I need...

rplain1 Loc: Dayton, Oh.

nadelewitz wrote:

If you leave a camera battery in its charger after unplugging it from AC power, is there drain on the battery? Will a battery run down in storage in the charger, more than if it is out of the charger?

I have Canons also, leave my batteries in their chargers in my bag - sometimes for a month or two.
They are still ready to go when I need them - fully charged (at least over 90% - they might have gone down a few percent).

PATFINN

No , there will not be an electrical drain to the battery .

once the charger is unplugged , there is not an electrical circuit , it is open ended .

think this way about this , you unplug a table lamp , does it stay lit up ? is there an electrical circuit ? no

now , if the contacts of the charger ( metal tabs that are plugged into the wall receptor ) are grounded to each other , there may be an electrical drain , due to ,, electric potential ( battery , ) completed circuit ( wire of charger and battery )
and a load drain on the battery ( resistance of charger transformer and wire circuit )

after all that .... I charge my battery and put the fully charged batter , still in the charger into my camera bag , it is good to go days / weeks later .
patric

TriX Loc: Raleigh, NC

PATFINN wrote:

No , there will not be an electrical drain to the... (show quote)

That lamp analogy would be true IF the battery contacts are connected directly to the AC plug contacts, but they AREN’T (there is a rectifier, maybe a switcher and/or a transformer and other components in the circuit). Just for fun, I measured my Canon charger: 1.19 megohms battery contact-to-contact when unplugged (either polarity). At 6V, it would draw 5 microamperes - negligible, but not zero. Other chargers will likely be different.

BebuLamar

TriX wrote:

That lamp analogy would be true IF the battery contacts are connected directly to the AC plug contacts, but they AREN’T (there is a rectifier, maybe a switcher and/or a transformer and other components in the circuit). Just for fun, I measured my Canon charger: 1.19 megohms battery contact-to-contact when unplugged (either polarity). At 6V, it would draw 5 microamperes - negligible, but not zero. Other chargers will likely be different.

Also the circuit contains solid state devices which the impedance changes with voltage. So with an ohm meter it may measures 1.10 MOhms but with the battery voltage it could be lower or higher.

PATFINN

At 6V, it would draw 5 microamperes - negligible, but not zero. Other chargers will likely be different.[/quote]

wow , good job !

I deal in amps , full and to the 1/10 decimals in my work

the microamps are a little out of my league .

good job ,

TriX Loc: Raleigh, NC

BebuLamar wrote:

Also the circuit contains solid state devices which the impedance changes with voltage. So with an ohm meter it may measures 1.10 MOhms but with the battery voltage it could be lower or higher.

Sure, and I also don’t know the voltage at the probe tips on the 20M scale (although I did swap probes to make sure I wasn’t forward or reverse biasing a junction) - just too much trouble to measure the actual current. Actually, I can’t see a good reason to care - I can’t imagine why I’d store a battery in an unplugged charger - I’d just use the terminal cover; but after 5 pages, I thought what the hell...

BebuLamar

TriX wrote:

Sure, and I also don’t know the voltage at the probe tips on the 20M scale (although I did swap probes to make sure I wasn’t forward or reverse biasing a junction) - just too much trouble to measure the actual current. Actually, I can’t see a good reason to care - I can’t imagine why I’d store a battery in an unplugged charger - I’d just use the terminal cover; but after 5 pages, I thought what the hell...

I don't have the Nikon charger with me here at work but I have a laptop charger. I measured the resistance with the ohm meter and it shows 4 Mega Ohms. With a 12V DC connected to the output of the charger (unplugged) the current is 11.2 mA which is significantly higher than the resistance measurement would suggest. However, still not high enough to worry about. But I would never keep the battery in the charger when not plugged in.

LA Loc: Little Rock, AR

TriX wrote:

That lamp analogy would be true IF the battery contacts are connected directly to the AC plug contacts, but they AREN’T (there is a rectifier, maybe a switcher and/or a transformer and other components in the circuit). Just for fun, I measured my Canon charger: 1.19 megohms battery contact-to-contact when unplugged (either polarity). At 6V, it would draw 5 microamperes - negligible, but not zero. Other chargers will likely be different.

Not zero, obviously. But at that rate my 1 A-hr Sony battery would discharge to 50% in just under 23 yr!! In practice batteries drain much more rapidly than that on their own internally, i.e., chemically. In comparison the draining-due-to-discharding-thru-the-charger is for all intents and purposes zero.

PHRubin Loc: Nashville TN USA

PATFINN wrote:

No , there will not be an electrical drain to the battery .

once the charger is unplugged , there is not an electrical circuit , it is open ended .

think this way about this , you unplug a table lamp , does it stay lit up ? is there an electrical circuit ? no

It is not the same thing. There is a transformer in the charger. While the primary side (the side plugged in the wall) is open circuited, the secondary side (feeding the battery) is not if there is a bettery left in it. However, the circuitry is such that the reverse current through the rectifier diodes trying to discharge the battery is so low as to be ALMOST non-existant.

Also, there ususally are capacitors in the charger. They hold a charge for a few seconds, unlike the old tube TVs that could hold that charge sometimes for days and give you a hefty jolt, even when turned off and unplugged.

TriX Loc: Raleigh, NC

LA wrote:

Not zero, obviously. But at that rate my 1 A-hr Sony battery would discharge to 50% in just under 23 yr!! In practice batteries drain much more rapidly than that on their own internally, i.e., chemically. In comparison the draining-due-to-discharding-thru-the-charger is for all intents and purposes zero.

Exactly. 👍👍

BebuLamar

PATFINN wrote:

No , there will not be an electrical drain to the... (show quote)

If you connect the 2 blades of the charger together there won't be any more drain than you don't. If like you said leaving the battery in an unplug charger would be serious potential of shorting the battery.

pocketchange

Dikdik wrote:

A sensitive ammeter will show the discharge.

Dik

Not according to my FLUKE meter (with NIKON.)

Dikdik Loc: Winnipeg, Canada

pocketchange wrote:

Not according to my FLUKE meter (with NIKON.)

Good machine, got one too ... maybe the 'switching power supply' leaves an open circuit as opposed to a transformer and rectifier.

What happens if you connect an ohmmeter between the battery contacts; does it show an open circuit?

Dik

BebuLamar

pocketchange wrote:

Not according to my FLUKE meter (with NIKON.)

Which one? I have 7 of them.

rjriggins11 Loc: Colorado Springs, CO

nadelewitz wrote:

If you leave a camera battery in its charger after unplugging it from AC power, is there drain on the battery? Will a battery run down in storage in the charger, more than if it is out of the charger?

Yes it will. Chargers have electronic components that leak electricity and will discharge a battery. By the way, if you leave them in too long, they will discharge completely. This kills lithium polimar batteries. I don't recommend storing the batteries in the charger.