The "Canon Test Method" usually assumes optimum conditions. For example, battery life on bodies is usually performed with the lightest, cheapest lens (50/1.8 II), and that there are 20 seconds between exposures.
The typical EOS user is a user of zoom lenses, which are bigger and heavier than the 50/1.8II. There is also significant battery draw for simply metering the scene, even if no exposure is taken, since all of the electronics power up, and AF is activated.
For tests involving flash, it is assumed that the flash is exactly half discharged on every shot. With the A-TTL program, it attempts to stop down as far as possible, meaning that the flash is closer to fully discharged. With built-in flash, you lose light because you probably don't have the 50/1.0L. That is to say, you run into the guide number formula, distance = GN/aperture, and thus require a full flash.
Some 2CR5 batteries may just not be very good. If you find a brand that works well, stick with it.
The main draws of power are the electronics and motors. When playing with AF you're activating motors. Also, when first familiarizing one's self with a camera, one tends to leave the display on for longer intervals. When any switch is pressed, the camera electronics come on--even when the main switch is the LOCK position!
Here are three ways to test this assertion:
With the camera in aperture priority, set the minimum aperture for the lens. Use hold down the DOF preview button, and then turn the main switch to "L". Notice that the lens stays stopped down. Remove the lens. It's still stopped down. Now reattach the lens. As if by magic, the aperture opens again!
With a 430EZ attached, turn the main switch to "L" and let the flash go to "sleep". Depress the shutter button or flip the AF/MF switch. The flash wakes up!
Find a radio station that picks up RFI interference, and play with the buttons. The electronics will come on and interfere. [640 kHz works for me.]
Robert M. Atkins posted a nice summary of measurements based on his 630. Newer cameras will draw more power due to faster CPUs and more features.
From: firstname.lastname@example.org (robert.m.atkins) Newsgroups: rec.photo Subject: EOS battery use - Some hard numbers
I just measured some current draw data for an EOS 630 with a 35-135 USM lens which might be of interest:
Lens focusing (infinity to close focus) 200mA for 0.25s Film winding (1 frame) 600mA for 0.25 s Mirror flipping up & shutter release 350mA for 0.1 s Exposure determination (i.e. depress shutter release 1/2 way to give exposure reading 100mA for 6 s Film rewind (36 exposures) 450mA for 8.5 s Any function button 100mA (current is drawn until function is set)
Maximum current drawn was a 1.6 amp transient on motor start up
Adding up these numbers you find that to focus from infinity to closest focus, get an exposure reading and hold it for 5 seconds, release the shutter and wind on one frame takes about 835 mA.seconds. Let's be cautious and say I missed a few transients and assume the real value is 1000mA.seconds. To expose a full roll of 36 exposures and rewind it would then require close to 40,000 mA seconds. A 2CR5 has a claimed capacity of 1300 mA.hr (= 4,680,000 mA.seconds), thus we should be able to get about 115 36 exposure rolls from a 2CR5!! However, if you focus a couple of times and take 3 exposure readings every time you take a shot (which is not all that unusual for the kind of work I do), then this number will drop by a factor of about 3, to maybe 40 rolls per battery. This still seems a little optimistic - maybe 2CR5s are not really 1300 mA.hr at the current draw rates found in the camera?
The numbers do point out a few things thought. First, the small USM lenses do not draw much power, so there would be little to be gained by using manual focus. Second, the real power draw is when the shutter is depressed 1/2 way to get the exposure reading. If you don't take a picture you get 100mA draw for 6 seconds. If you do take a picture the current draw stops after the frame is wound (i.e. less than the full 6 seconds). Lastly, there is significant discrepancy between the claimed capacity of 2CR5s and the resultant theoretical number of rolls of film you should be able to get through the camera.
Bob Atkins AT&T Bell Labs email (direct) att!clockwise!rma
Brett Cheng has supplied similar numbers for the Elan:
Subject: Elan Current Consumption Numbers (long) Summary: test measurements of Canon EOS Elan power consumption Keywords: Canon EOS Elan battery power Sender: email@example.com (Brett Cheng)
All this discussion about power consumption in the EOS cameras got me curious, and since I've been meaning to do some power measurements on my Elan anyhow for some time, I thought I'd investigate a little. These are just some quick measurements done with what little equipment I have available at home, and I didn't try to accurately measure durations of the transients. If I get a chance some rainy day perhaps I redo these more accurately...
Bob Atkins recently posted a very informative list of measurements on his 630. I haven't attempted here to break down the consumption of the actual meter, shutter release, mirror flip up, film wind, etc. of taking a photo as he did. I expect the Elan is very similar in these respects, so this is not a repeat of his measurements for the Elan.
However, since some other recent posts have been discussing standby current and flash charge current, I've mainly concentrated here on measurements relating to these or other unexpected power consumption. I apologize for the length - I think there are a few things of interest and of relevance to the recent/ongoing battery discussion.
In particular, I set out to answer for myself these general questions:
a. check the "L" and standby current (expected to be very low)
b. outside of the obvious items (motor wind, using flash, etc) are there any other significant current draws?
c. is the built-in flash always charged, and will attaching a 430EZ change this as suggested in a recent post? (wasn't sure about this one)
The test subject:
Canon EOS Elan, 28-80m f/3.5-5.6 USM lens,
Duracell-XL DL245A battery (2CR5)
Test method: definitely not Canon's Standard Test Method :-)
Details: (for those of you still interested) ------- First the measurements, numbered for later reference; detailed comments follow... Cmd Action/condition (mA) duration # Dial 1 L "off" 0.024 continuous 2 P "standby" 0.025 continuous 3 L turn QCD or main dial 90mA 2 sec (!) 4 L press shutter or any button 90mA momentary 5 L hold any button except shutter 90mA 2sec max, then->standby then 90mA momentary on release 6 P press shutter 1/2 way, AF off, no AF light ie meter only 103mA 6 sec 7 L->P shortly after P->L 93mA 2 sec 7a L->P after camera off for several minutes 200ma+ transient, 93mA 2 sec. 8 P turn QCD or main dial 93mA 2 sec 9 P push AF mode button 93mA 2 sec max, then-> standby 90mA 2 sec on release 10 P push Drive mode button 93mA 2 sec max, then-> standby then 90mA momentary on release 11 P push Drive mode button & select self-timer mode 3.6mA continuous while in self timer/IR remote mode 12 P press shutter 1/2 way, then AE lock 100mA until 6 sec after release of AE lock 13 P focus inf-closest ~350mA <1sec (not too accurate) 14 P pop up flash 300mA <1sec (ditto) 15 P press shutter 1/2 way red eye lamp on 280mA while shutter depressed and lamp on 16 P after fire flash 2.2A peak decays to 500mA after 5sec, then -> standby 17 P->L after fire flash, immed popdown flash, -> L 2.2A peak decays to 500mA after 5sec, then -> off 18 P->L after fire flash, immed remove battery, -> L, popdown flash, then replace battery 1.9A peak decays to 500mA after 5sec, then off 19 P->L repeat 18 with 430EZ attached & charged before replacing battery 1.9A peak decays to 500mA after 5sec, then off 20 L camera in standby for several minutes, then L. Now remove battery for several min, then replace battery ~700m <1 sec, then->off 22 P rewind film (36exp 280mA(av) 14 secDetailed Comments:
A. Standby vs. off seems to draw only very slightly more (~1microAmp). So indeed storing the camera with battery in "L" mode should last ~5.9 years. From this fact alone, I don't think it's worthwhile taking the battery out for periods of non-use (unless you're talking years of non-use)
B. Interestingly 3,4,5 show that even when camera is "off" (L), the buttons are not completely disabled. I was surprised to find that the main and QC Dials draw current for 2sec when camera is off. So don't fiddle with those dials. Curious that "L" doesn't actually disable those controls.
C. Item 6 is expected, matches similar measurement for EOS 630. If you press the shutter 1/2 way a lot, this will be significant, and this doesn't even include focusing. Aside actually taking the picture (which you presumably need to do eventually :-) ), and using the built-in flash, it still seems that metering/focusing several times before the actual shot is the most wasteful.
D. Not sure what 7 is - you always get ~90mA for 2 sec when you turn on the camera. This is likely the micro and other circuitry starting up before entering standby - note all the other 90mA x 2sec items. But perhaps 7a could be the flash charge being topped up...
E. Item 11 is interesting, but not unexpected once you think about it - standby current is much higher when in self timer/IR remote mode. This would be because the IR detector has been enabled. Leaving the camera in this mode for extended periods could contribute to shorter battery life. However, if you set up camera for self timer/remote photo and it takes you lets say 3-4min before you finish, the extra consumption for remote mode is not much more than the consumption of a 6sec metering period, so under normal circumstances this is nothing to worry about.
F. Item 14 - most of this is probably the flash zoom head motor which moves the zoom head when you initially pop up the flash. Similar reading @28mm. This reading was done with the camera already on standby for a while. Item 15 shows red eye lamp is another battery eater as expected.
G. No surprise here - 16 shows using the built-in flash is expensive on batteries. The flash charge measurement is probably not too accurate but I tried to catch the peak current and approx duration.
H. 17-19 show after using the flash, it is charged up again even if the camera is turned off - this along with 7a seem to confirm earlier posts saying that the flash is always charged when the camera is turned on and the battery is in. Having a 430EZ on and attached doesn't seem to change this as someone earlier had suggested. Didn't think it would...
I. I think 20 is similar to 7a, topping up the flash charge...Perhaps if I waited longer, the current would be greater? - I don't know, I didn't have the time to try... Anyhow, this tells me that maybe the idea of some recent posts to remove the battery after every use is maybe not such a good idea, especially if it is true that the flash gets partially charged up when you insert the battery. Then again, maybe no difference in the end since with the battery installed and the camera off for a while, the flash will discharge eventually and it will need to be charged again (7a?). Probably need some more measurements regarding this matter to be sure...
Brett Cheng uunet!jericho!brett firstname.lastname@example.org
No. You can run the battery down until it's completely dead. It can last for up to 2 rolls of shooting (maybe more). However, it is a good idea to buy a spare battery by the time the camera gives you one blinking bar.
No. The EOS cameras are designed to remember their state information between batteries. On the EOS-1, there is NOVRAM maintained by a lithium button cell. The cell is supposed to be good for 3 to 5 years (under normal conditions). On the EOS 600 series, there is an EEPROM which gets updated. It is supposed to last through 10000 updates. If it wears out, it will need to be replaced by a Canon service centre.
I assume the 10s/Elan/A2/Rebel also have the EEPROM [RMA]
No. The shooting capacity of the A2/E is unaffected by the VG10.
(see 8.1.12 for details of the external battery pack)
Other than the obvious cutting back on the use of the built-in flash, try setting CF13. Since metering is a relatively expensive operation, and since it operates for a relatively long time, it is probably a good idea to cut back if you can.
Harald Brandt reports that metering on the EOS 5 costs 150 mA versus 23 uA for standby mode. By setting CF13, the metering goes off immediately after the shutter button is released.
He also reports that Canon Sweden was able to lower the cutoff voltage by 0.5V to prevent the camera from locking up before the battery is totally consumed, and that he was able to get the operation performed under warranty. Other Canon service folk may not have heard of this, so keep nagging!
Here is an article posted by Harald Brandt [edited down a bit because it covered some unrelated topics--ACS]:
From: Harald.Brandt@eua.ericsson.se (Harald Brandt)
Subject: EOS 5 & Battery life, Current drain, CF2, Flash
Organization: Ellemtel Utvecklings AB, Sweden
Date: Tue, 9 Feb 1993 18:37:00 GMT
CONTENTS: BATTERY WARNINGS, CURRENT CONSUMPTION [...]
In happiness of the new precious wonder camera, autofocusing and measuring every possible spot around me, even loading a film after some time, I soon noticed the battery symbol was half, and after the end of the film, camera said I should replace with a new one! In disappointment, I called Canon Sweden to complain. This was how it started.
They said that especially the EOS 5 is set very (extremely) high concerning battery warning. They have discussed this with Canon Amsterdam (which handles all Canon questions for Europe, and who in turn ask Canon Japan), and they have not gotten a proper answer on why, except general mumble about very cold weather in the northern Europe. Canon Sweden has decided to reprogram that thing for anyone with warranty who complains about too short battery life. The most fantastic thing is that they can do that by simply connecting a cord to the flash contact on the top, and then pushing a button on the computer! Very elegant! (They have previously also done that on EOS10, and those people have been pleased.)
The test/service program from Canon Japan contains the following recommended thresholds (on battery check or after pushing the shutter release halfway, i.e loading the battery with 150 mA):
Half symbol: 5.0 - 5.5 V Empty symbol: 4.5 - 5.0 V Flashing symbol: 4.0 - 4.5 V
With this, the shutter will be inhibited at about 3.5 - 4.0 V
Factory and service manual claim a "set voltage" of 4.2 V should be used to obtain that, but Canon Sweden says that the above thresholds will be exceeded by about a half a volt if set that way, and have instead found that he "set voltage" should be 3.6 V.
My camera was found to be set extremely high:
Half symbol: 5.8 V Flashing symbol 4.8 V Shutter inhibit 4.2 V
It is obvious that the above is a bit crazy, since even a new Li/MnO2 battery will deliver, at the most, about 5.8 V under load.
Now, after adjustment, my camera has the following thresholds:
Half symbol: 5.2 V Empty symbol 4.7/4.8 V Flashing symbol 4.3 V Shutter inhibit 3.6 V
I wanted them to measure current consumption on my camera to check if it is OK. The following was measured:
Standby (Camera ON) 23 uA Shutter button at half 150 mA (metering for 6 sec if CF13 is 0) Rewind with film 400 mA (I think it was set to fast (CF1))
The above is within spec. (Wind (forward) should be 650-800 mA in the spec.)
From the above, one can easily conclude that metering is very expensive. It does not matter if you set CF4 (disable AF) since circuits are either on or off (I have asked, but not checked myself). However, current for AF-motor is not included in the above values. It is extra, but only for a very short time (in contrast to Nikon, where it drains until it after some time has stopped hunting :-), don't be angry Nikon people, I am just teasing, I have myself been a Nikon guy)
One can also conclude that if you forget to turn your camera off for 24 hours, that corresponds to only 13 seconds of metering!! Every 6 second metering drains 0.25 mAh from the battery, and there are only 1300 mAh in it. So a good recommendation, while in your playful mode (measuring and AF-ing every possible spot. I still haven't passed that stage) is to set CF13 to 1, thereby setting the timer to 0 sec. Alvin said that would cause trouble if you want to shift exposure (not exp compensation) when in program mode. Yes and no. It makes it a bit awkward but it is possible: Use AE-lock button to get or lock exposure, shift exp (main dial) press shutter release half way.
I have also CF4 set (inhibit AF when the AE/CF button is pressed. Good fast alternative to turning the lens to manual when I want to preset focus to some point, or when using AI Servo. But so far, I can not claim to have a long habit of that way of working. What's your opinion? (And by the way, What does the letters "AI" stand for in "AI Servo"? It disturbs me that I do not know that.)
Best Photo Regards, /Harald
NOTE: See also section 8.1.10 for more information on A2/A2E battery use. NOTE: AI stands for Artificial Intelligence
NOTE: I believe that Canon USA are unwilling to make voltage adjustments to the A2/A2E unless the camera is outside the official Canon specs. [RMA]
It would appear that "Not all lithium batteries are created equal.". Canon sells a 2CR5 which is manufactured by Sanyo. Sanyo and Panasonic are the manufacturers of "genuine" 2CR5 batteries. All others are "equivalents" which may have different properties. So, try out various brands to see which ones deliver acceptable performance.
(see 8.1.12 if you have an A2/A2E)
In cold weather, the reaction rate of the chemistry within the lithium cells slows down. When very cold (-36 degrees and below), the reaction rate may slow down to the point of not being able to power the camera. This is particularly true if the battery is not at full charge.
One way is to keep swapping batteries in and out of a warm pocket, forcing the reaction rates back up. However,this is highly inconvenient when gloves are being worn, and may cause missed opportunities during battery changes.
Canon recommends the use of the EOS 1, Power Booster E1, and Nicad pack E1 (along with Nicad Charger E1). This setup is rated for 30 rolls of 36 exposures at -20 degrees F. For those who do not wish to invest in an EOS 1, Canon offers nothing.
However, there is a 3rd-party pack called an "UnderDog" from JVB Designs in (of all places) Miami Florida. It is a small lead-acid battery that can be attached to the bottom of the camera via the tripod socket (note that there is no tripod socket on the battery pack). A wire runs from the pack to a 2CR5-shaped module.
Since the EOS bodies are not designed for this sort of thing, a notch will need to be cut into the battery covers of units like the Elan, 10s, and Rebel. For the 600-series, the grip will require modification. (The A2/E version is still undergoing development.)
For extremely cold environments, the battery unit can be placed in a pocket to keep it warm. When the battery unit is not required to power the camera, it may be used as a low-voltage pack for a flash in conjunction with the appropriate Quantum battery module.
The last known price for 2 batteries and a charger was approximately US$150 The manufacturer can be contacted at:
JVB Designs PO box 53-0095 Miami, FL 33153. 305/754-7862
or via Compu$erve at: 70671.1312@CompuServe.COM (John Van Beekum)
By the way, don't forget that power is only one consideration in cold weather shooting. Watch for condensation problems (lens, film, eyepiece,etc.), moisture in the flash, etc.
This information was gathered from Canon sources, however it is not a direct quote from Canon and should not be treated as such.
The rate of battery consumption is different for the different cameras in the EOS line. A lot of things influence battery consumption, including the CPU speed of the camera electronics, the winding speed (fps), the use of some functions such as eye controlled focus (A2E) and of course the built in flash, red eye reduction and so on. Thus the newer full featured bodies, like the A2E, use more battery power than simpler models such as the Rebel. The approximate order of efficiency (with no flash use) is Elan, (Rebel and 630/RT), (10s and EOS-1), A2, A2E.
Battery use symbols. Basically you can use the camera up to the point at which the shutter will no longer fire. The battery use indicator is a guide, but the camera will function normally all the way up to the point where it decides to prevent you from taking a picture. The battery level indicator on the A2/A2E is set differently from that on other EOS bodies, and may seem to indicate the battery is running out faster than on earlier cameras. Even though the manual states that you should replace the battery when the battery indicator reads empty, Canon now state that this is not needed. For maximum battery life Canon recommend that you continue shooting until the shutter no longer releases (just make sure you are not just about to get the shot of a lifetime when that happens!). Depending on just how the internal battery check levels are set you could get as many as 5 more rolls of film through the camera after the battery indicator shows empty. On the other hand you may not get more than 1 roll if the internal levels are set at the low end of the permissible range.
Canon have set the point at which the shutter fails to fire at a battery level which will give full camera function under the most adverse conditions of camera use. For example for the A2E the camera will quit when the battery voltage drops below the point at which it could use eye controlled focus and built in flash with red eye reduction at a temperature of -20C (4.2 volts for the A2E). There is some discussion as to whether this is too high (see the posting by Harald Brandt in 8.1.7 above). As far as I know, Canon USA do not support the reprograming of the cutoff voltage to a lower level. My guess, based on my own opinions and not those of Canon, is that they do not want to lower this voltage and run the risk of the camera operating improperly under adverse conditions. With the lower voltage you might be OK most of the time, but you could not be certain that every frame would be properly exposed and focused when operating below 4.2v. Note that since the A2/A2E can draw more current than earlier cameras, the battery voltage at cut off has to be set higher to ensure full operation under all conditions.
Not all batteries are equal. A new 2CR5 should have a terminal voltage of 6.4 volts. However the real test of the battery is under load. Some batteries may read 6.4 volts off load, but show a significant voltage drop when under load, while others may show little voltage drop. Thus a "bad" battery might give a low battery indication after only a few rolls, particularly on an A2/A2E where the low battery threshold is higher than on other cameras in the EOS line. In the absence of hard data it is difficult to say which batteries are "best". If you get poor performance, try a different brand. If you are happy with battery performance, stick with the brand you are using. I have had good luck with Sanyo and Panasonic batteries, but your experience may be different.
The are no rechargeable 2CR5s at present. A NiCad of that size would not have enough power to operate the camera for much more than about 1 roll of film, not even that if you use flash. There are rechargeable Li cells on the market with much higher capacity than NiCad cells (3 or 4 times as much), but they are not yet available in a 2CR5 package. Only the EOS-1 has the capability of using AA cells, which are available in rechargeable form. The only problem with the 2CR5 seems to be its cost, typically $12 or so. However there is considerable mark up on these batteries. If you buy in bulk they can be obtained retail for around $6. Rumor has it that "Price Club" stores sell 2CR5s for about $6 also.
I have built a 4 x 1/3 AA cell rechargeable NiCad battery pack in a 2CR5 package myself as an experiment. Note that you really need 5 NiCads to give you 6v, 4 will only deliver 4.8v - but you can't get 5 1/3 AA cells into a 2CR5 shaped package! With a full charge it will provide power for about 1 roll of film (36 exp) in an EOS 630 if you do nothing except press the shutter release each time. If you do any kind of focus "checking" and exposure "checking" or mess around with many of the settings etc. you probably won't make it through 1 roll. Only if every 2CR5 battery store in town was closed and you had to take a few pictures would this approach be worth trying. My advice: Buy 2CR5s until someone comes out with something better!
The BP-5 is an external D cell battery pack for use with the A2/A2E. It consists of a 4 cell battery holder, a dummy 2CR5 battery, a 4 ft coiled cord and a dedicated camera grip cover. List price is $75. Canon claim 200 rolls with alkiline cells or 100 rolls with NiCads at 20C/68F (cf 26 rolls with a 2CR5). At - 20C/-4F a 2CR5 will give 8 rolls, as will the alkaline pack, but the NiCads should be good for 65 rolls. (all figure for 36exp rolls, eye controlled focus on, 100% AE, 0% flash). An external AA cell pack is currently under development by Canon, but as of 11/93 no details are available.
If all you want is "a little bit more", you might want to simply shop more carefully when buying NiCad AA cells. Some cells are rated for 600 mAh, whereas others for 800 mAh. Another option is lithium AA's. Popular Photography stated that one set of lithium AA's lasts about twice as long as one set of NiCads. However, lithium batteries are expensive and are not rechargeable.
The 430EZ has a high-voltage jack. It is designed to accept power from the Canon Transistor Pack E. With it, recycling time can be reduced to 3 seconds and shooting capacity is on the order of 250 full-powered flashes with the NiCad Pack TP. The Transistor Pack E will accept 6 "C" cells, or a special NiCad pack from Canon. Canon does not recommend using NiCad cells in the Transistor Pack E. (I have no idea why not.) Canon warns the 430EZ can be damaged from overheating if fired at faster recharge rate provided by the Transistor Pack E. Canon has recently added the "Compact Battery Pack E". It holds 6 AA cells and also plugs into the high-voltage pack. It may be attached to the camera via the tripod socket, or put in a shirt pocket, or attached to a belt via the included carrying pouch. It is rated for100 full powered flashes with nicads.
Canon doesn't recommend the use of non-Canon high-voltage packs (of course), but no reports [to my knowledge] of a 3rd-party pack damaging a430EZ have been reported. The most popular 3rd-party H packs are based on lead-acid technology. To attach the pack to the 430EZ, an additional adaptor cable is required. Damage to your flash as a result of connecting to a 3rd-party pack will (of course) void the warranty.
A low-voltage pack.
A low-voltage pack.
A low-voltage pack connects to the battery terminals of the flash and delivers 6V at a slightly higher current than NiCads would normally provide. Some packs are just big NiCad batteries. Others are lead-acid. To get the power from the pack to the battery terminals, a matching "battery adaptor" is required. These adapters are designed to fit into the battery chambers of specific flash units. Since there is no opening to run the cable to the battery adaptor, the door to the battery chamber must be left partially open, or a notch must be cut into the door. In the case of the former, the battery door is usually held shut with a velcro strip.