Digital SLR: monitoring battery life

[ruslan]

<p>I shoot with E-420 and I wonder how I should monitor the battery life during the shooting to be ready to save energy or recharge. Battery life is shown when starting a camera, then the indication disappeares.I want to control battery life in percentage as I do it with my laptop or my 2000-year-made Sony Handycam.<br>

BTW, how many shots can I take with LCD is OFF, using NO flash, with 25/2.8 pancake under warm temperature?</p>

[john_robison3]

<p>With digital having a spare battery charged up is the best insurance against having the camera die at the wrong time. My E-410 seems to run 300~400 shots with it's battery fully charged but even so I always have a spare battery ready to go.</p>

[vick_vickery]

<p>Like John, I keep extra batteries on hand and charged...I've found that I tend to ignore the battery indicator until the camera suddenly quits with no further warning! Recharge your battery weekly even if it doesn't need it and you probably won't get caught without power!</p>

[GerrySiegel]

<p>I am not an electrical engineer yet I know that battery life is a variable that is hard to predict. Some of the things you haven't accounted for besides LCD and ambient temperature. - the size files you are processing to the media, - the age of the battery itself,- number of charge recharge cycles past - how often it has to move the focusing mechanism at distances from closeup to distance- the trickle discharge off of a stored battery. Good part is that, to my limited knowledge the little red warning guage comes on when there is a drop in voltage of X amount beyond a standard and so you have plenty of time to pop in a freshly charged spare. I think the advice to keep one handy is the only way to go. I am sometimes surprised to see the guage come on when I did not suspect it could. You just use it and find out how long your battery can last. Does that help, Ruslan?</p>

<p>Camera makes could put in a" fuel guage," and add some expense we might not want to pay..even then it might not be predictive of how much longer before voltage drops to a less than a " minimal electrically acceptable" level for that camera. I do not believe there is any downside to re charging or topping off a half full Li Ion battery on a schedule. Anybody know different, I would sure be interested?</p>

[phototransformations]

<p>There's no problem with fully charging a half-charged battery. There are, however, ways to build electronics into the battery and camera to much more precisely monitor how much charge is left, and even how much life is left in the battery. My Nikon D80 tracks these things and appears to be quite accurate in predicting when the battery will run out of juice. I have not yet worn out any Nikon batteries, but I would bet it's accurate there, too.</p>

[mike_proudlock]

<p>As a physicst ( and having worked with battery technologies in a previous carerre), recharging a partially discharged battery will damage the battery in the long term. Current battery technology is much more resistent to this than older types, but there is still a memory effect in time, resulting in a drop-ff in performance. To maximise battery life it should be fully discharged before recharging.<br>

I have found the battery indicator in both the E-520 and E-30 are actually pretty reliable, and give a good degree of warning when the battery is getting low (i.e. still with a few tens of shots to go). Carrying a spare, fully charged battery with you covers the chance of the battery dying duringa session. I have found you can find some much cheaper, but good quality, equivalent batteries on the Internet (£10 rather than £50) with no perceptible diference in performance. With both OEM and replacements I get 500+ shots with a full charge on either camera.</p>

[phule]

<p>[[recharging a partially discharged battery will damage the battery in the long term]]</p>

<p>[[ To maximise battery life it should be fully discharged before recharging.]]</p>

<p>As your advice here runs completely contrary to everything else I've seen written about lithium-ion batteries, can you provide any proof of these statements?</p>

<p> </p>

[mike_proudlock]

<p>I cannot cite technical literature etc., although an article in a UK PC magazine made the same points when looking at how best to manage rechargeable batteries in laptops, phones etc. Lithium Ion batteries suffer far less from memry effetc than previous technologies, but it has not been eliminated.<br>

From empirical experience, from personal equipment (all with LiIon batteries), an electric toothbrush that was repeatedly unplugged during the recharge cycle died after about 9 months. Its replacement which has been run donw and only then recharged is still going strong. Similarly, rechargeable AA batteries used by my family that have been drained bfore recharging are holding consoderably more charge than those that have been topped up. The on electronic device I have that gave any info in its manual on battery life also provided a charger with a facility to discharge the battery safely. This particular battery is still going strong after 4 years. These are, of course, small samples, so no necessarily statistically valid.<br>

Professionally, I am responsible for an estate of several hundred laptops and mobile phones. Over these devices, a significant number of batteries start failing well within the lifecycle of the devices (~18mths for laptop batteries). These are frequently partially discharged while their users sre in meetings, then dropped back into a docking station and topped up. Clearly this is not the only factor at play here as there is a clear variation between users. The number of devices, hwoever, does make this a valid sample. <br>

Although battery and equipment manufactures don't supply anything on battery care, in discussions with specialists, they all say that it is critical to battery performance to fully charge and discharge several times when it is new, and to try to maintain this in normal use.<br>

Getting back to cameras, I have always drained my camera batteries before recharging. I have been using an Olympus OEM battery and a generic repalcement over a year and not only can I not see any difference between the 2, but also no apparant dfference between the old batteries and a new pair purchased when I upgraded my kit.</p>

 

[phule]

<p>AA rechargeables come in different flavors (NiMH are different than NiCd) and have no relationship to the technology in lithium-ion batteries. NiCd batteries suffer from the memory effect. NiMH's do not. Your charger that came with a discharge function was for NiCd batteries. Again, this has nothing to do with lithium-ion batteries.</p>

<p>Lithium-Ion batteries are damaged by frequent deep cycling. In cases where the voltage is allowed to fall below a certain threshold, the battery will be rendered useless. This is different than running the battery down to the cut-off point of the electronic device. <br /> Lithium-ion batteries also age regardless of use. They will generally last between 2 and 3 years (though possibly more, of course). Buying a device with a lithium-ion battery that's been sitting on the shelf for a year means you have a year old battery.</p>