Canon EF "black beauty" battery eating problem

[janne_leimola]

<p>My Canon EF camera is eating batteries, even if it's turned off and the winding lever is in locked position. Light meter is on all the time when "CAT" switch in normal and the camera is shut off. Is this normal? I opened the bottom plate and cleaned the contacts. All the wires seem to be in place. Should I look deeper into the camera to find the problem? What I have read here, it seems that it's a common problem that batteries don't last with EF. Is there a solution for this?</p>

[yockenwaithe]

<p>The light meter will likely always be on unless it's in complete darkness, that's just how those older cameras work. A good solution [if you don't mind doing this every time] is to take the battery out when you're done using the camera, or make sure that there's absolutely no light reaching the sensor, as even a little light will turn it on and eat the battery</p>

[richard_cook2]

I have one EF that eats batteries and another one that doesn't.

Some EF's eat batteries and some don't.

Sadly you have one that does.

[jim_bielecki1]

<p>I haven’t owned an EF in 40 years but when the camera’s “on/off” switch is off, the meter should be off. If the meter is still reacting to light, something is amiss with your camera. Either time for a repair, or take the batteries out of the camera when not in use.</p>

[paul_wheatland]

<p>The Canon EF has an internal voltage regulator which may be on constantly allowing use in pairs, alkaline, silver, hearing aid, or mercury button cells. I suggest you remove batteries when not in use. The electronics are aged, repair may not be available. If you don't require speeds below 1/30 use camera without batteries and meter with handheld exposure device.</p>

[mwmcbroom]

<p>I own three EFs, two of which eat batteries at a moderate rate. With the switch off and the wind lever pushed in, using zinc-air hearing aid batteries, these two cameras will drain the batteries in about a month. Usually I'll get 9 to 10 months out of a zinc-air battery in my Canons where they power the meter only. Since these must also power the shutter, perhaps it's normal to see a reduced life with zinc-airs. But given that I've just allowed both of these cameras to sit so I could observe the battery consumption rate, obviously the shutter isn't an issue.</p>

<p>To me, a month, while excessive, is tolerable at least.</p>

[User_4136860]

<p>My E.F had the same fault when I bought it and I had it serviced I have no problems with it now, your camera's electronics have a fault that needs professional attention , I suggest you have it repaired by a pro.</p>

[mukul_dube]

<p>I agree with what Jim said.</p>

[michael_linn]

<p>Let's clear a few things up.<br>

There is no need to use zinc-air batteries in an EF. It has bridge circuitry and will be happy with cheaper and longer lasting 1.55v alkaline batteries.</p>

<p>The batteries only power the shutter timing at speeds slower than one second. Remove the batteries and try it if you think otherwise.</p>

<p>The fact that the light meter is still on even when the camera is turned off likely points to a problem in the switch mechanism. It is a leaf switch controlled by a pin attached to the switch. This is a very complex camera and it is possible to remove the top, reattach it incorrectly, and have the switch pinned in the wrong position. When switched "off" there should be no power to the camera at all.</p>

[Alex_Es]

One of my EFs does that. I take the batteries out.

[Keith S in Arizona USA]

<p>You guys with the EF's that drain batteries . . . . . . .</p>

<p>. . . . . . . send them to Ken Oikawa:</p>

<p>Ken Oikawa <br /> 28288 West Worcester Rd. <br /> Sun City CA 92586 <br /> Ph: 951-246-9136</p>

<p>He will fix the electrical issues that you have. It is <strong>NOT</strong> normal for an EF to drain batteries with the switch OFF.</p>

<p>P.S. Once the 'air seal' is removed, Zinc-air's will deteriorate rather rapidly --- even when not in use --- that is just the way they are. As has been noted, there is NO reason to not use the 625-type 1.55 volt cells due to the voltage regulation circuit of the EF design. The 1.55 volts will be regulated down to 1.35 volts, so not to worry. It is unfortunate that not all EF owners will be advised of this.</p>

[janne_leimola]

<p>Thanks to everyone for the advices. I have 625-type batteries in my EF. They drain if I leave them in the camera overnight.</p>

<p>Today I looked under the bottom plate again and took the battery holder out. Couple of wires came out from the soldering points. I found this EF repair manual: http://www.baytan.org/prak/pdf/serv/CanonEF-serv-rep.pdf I'll try to re-solder and see how things work after that.</p>

[mwmcbroom]

<p>Guys, I mentioned using the zinc-air batteries in my earlier post only as a means of illustrating the sort of drain my EFs are experiencing. For me, they're handy. I have dozens of them around, but at the moment, none of the 625s. And yes, I'm aware of the EF's bridge circuit. Also, I don't recommend using alkalines because of their discharge profile. The silver oxide ones are more expensive, but they have a discharge profile that is much closer to the original PX625s. I dunno, maybe the bridge circuit helps in this respect, but I'll wager that a silver oxide battery will provide longer life than an alkaline also.</p>

 

[flavio_egoavil]

<p>Hi Janne,</p>

<p>You need to dissasemble the camera and check the on-off and battery check contacts. In particular the on-off contact has a working distance in the OFF position, if it gets too close it might cause battery drain. </p>

<p>Hi Michael,</p>

<p>No need for special batteries on the Canon EF. The way the circuit is implemented, the voltage differences or the discharge will not have an effect in metering. </p>

<p> </p>