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Extended battery life for remote shooting

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Offline Mlapse

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Re: Extended battery life for remote shooting
« Reply #10 on: 27 / March / 2018, 05:46:53 »
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Something like this?
http://www.radioparts.com.au/product/03296520/c12-40dg-12v-40amp-deep-cycle-gel-battery-century#.WroBB4huaUk

deep cycle doesn't help with only 8watt/hour power drain, any cheap car batterie will do
I was actually thinking of something from a truck or a golden holden 3.3 or a series of ups batteries, not a batterie the size for a toyota yaris..but I'm sweet with this, are you?

this would give you a 1 day buffer safely and 2 days until the batterie is dead with no charging.

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Don't mean to boast but sunshine is good here, in Byron Bay, the most easterly point of Australia.  Average temp is 75F and we get a mere 9.9 days of rain per month.
Sending you warm wishes
Sdack
It been a long time since I was in that area, but I can remember you are right....

here is a bit of math involved.

fyi a sun hour is 1 hour of maximum sunlight per m2 for your area, at the equator it is 1000watt/m2, you are probably up at 800-900watt/m2 in summer, don't know about your upcoming winter maybe 700watt/m2.

If bleak days deliver 250watt/m2 per hour that would mean you need 4 hours of daylight to have one sun hour.

If the panel is not in a 90 degree angle with the sun the surface collects less sun dropping the amount of light per m2 of panel surface(and this is a fact for most hours of the day).

Per degree temp rise your panel will also produce less energy, about 0.5%

Is this understandable for you?

It's not about those sunny days, if you have 8-10 sun hours, lets say your 50watt panel deliveres 300watt a day on these days
your suggested batterie is 480watt.
In the morning (let's say after 16 hours of draining and that is longer than in actual life) you have 16x8=128watt used, the panel charges that in 3 hours, leaving the rest as unused, just to compensate batterie discharge and the 8 watt/hour for your rig until sun goes down and panel stops charging.

Now you have a poor, clouded day, about 1/2 sun hours, it's colder so let's say it gives still 20watt, that mean your batterie is discharged by 172 watt a day.
this setup would then run 2-3 of these days before your batterie is completely flat and you wished you would have arrived earlyer.

You can probably find info of average sun hours for your region to make an good estimate what is needed.

You could use a li-ion pack of f.i. an electric bike to take along on those cloudy days to charge the batterie if voltage is getting low.

And I thought my setup was bulky......with only 2.5watt/hour drain.
what camera do you use for your setup?
« Last Edit: 27 / March / 2018, 06:27:15 by Mlapse »
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Offline Sdack

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Re: Extended battery life for remote shooting
« Reply #11 on: 27 / March / 2018, 19:50:15 »
    Quote
    deep cycle doesn't help with only 8watt/hour power drain, any cheap car batterie will do
    I was actually thinking of something from a truck or a golden holden 3.3 or a series of ups batteries, not a batterie the size for a toyota yaris..but I'm sweet with this, are you?
    That's even better.  It's hard to get past the marketing these days, so I'm very grateful for your insights here.  I would have been sucked in to spending $200 plus.
    Quote
    this would give you a 1 day buffer safely and 2 days until the batterie is dead with no charging.
    That's great.
    Byron Bay's solar energy resources
    On average, Byron Bay receives solar irradiation levels of around 4.51 kilowatt hours per square metre daily. Ideally, solar panels installed in Byron Bay should face a Northerly direction. Acceptable panel angle range is 13° to 23° and the optimal angle is 18°.
    Quote
    here is a bit of math involved.

    fyi a sun hour is 1 hour of maximum sunlight per m2 for your area, at the equator it is 1000watt/m2, you are probably up at 800-900watt/m2 in summer, don't know about your upcoming winter maybe 700watt/m2.
    This stuff is fascinating, I've never come across it but it's so fundamental.. love it!
    Quote
    If bleak days deliver 250watt/m2 per hour that would mean you need 4 hours of daylight to have one sun hour.

    If the panel is not in a 90 degree angle with the sun the surface collects less sun dropping the amount of light per m2 of panel surface(and this is a fact for most hours of the day).

    Per degree temp rise your panel will also produce less energy, about 0.5%

    Is this understandable for you?
    Yes I can follow it and it makes sense but not quite enough for me to run with it alone, so I appreciate your elaboration.  I've not heard of the steca charge controller you mention.  Would that come separately to the panel?
    Quote
    It's not about those sunny days, if you have 8-10 sun hours, lets say your 50watt panel deliveres 300watt a day on these days your suggested batterie is 480watt.
    When you say "your suggested batterie" do you mean the one I provided a link to, or is the 480watt batterie, a suggested size?

    I remember my dad telling me that watts = volts times amps but it's confusing how batteries are marketed as Amp Hours. 
    My novice math suggests that if it's a 12volt battery running an 8 watt device like mine, then it should run on a fullycharged 480watt battery for  480w /8w = 60 hours.  Am I right?
    Quote
    In the morning (let's say after 16 hours of draining and that is longer than in actual life) you have 16x8=128watt used, the panel charges that in 3 hours, leaving the rest as unused, just to compensate batterie discharge and the 8 watt/hour for your rig until sun goes down and panel stops charging.

    Now you have a poor, clouded day, about 1/2 sun hours, it's colder so let's say it gives still 20watt, that mean your batterie is discharged by 172 watt a day.
    this setup would then run 2-3 of these days before your batterie is completely flat and you wished you would have arrived earlyer.
    To clarify my system, my power draw was measured during active daytime shooting of photos, when the camera was powered up and uploading images to the Internet over a 3/4G cellular modem.  After hours, the computer powers the camera down, at which point the Raspberry Pi's idling draw is a mere 120 milliamps as quoted here http://raspi.tv/2017/how-much-power-does-pi-zero-w-use, .
    Quote
    You can probably find info of average sun hours for your region to make an good estimate what is needed.
    See Sun figures above
    Quote
    You could use a li-ion pack of f.i. an electric bike to take along on those cloudy days to charge the batterie if voltage is getting low.
    If mains power is available at the location, would I be able to have it charging the battery too?  Experience on my first deployed rig tells me I can't count on continuous power.  Storms and people cause interruptions.  Construction workers are pretty anti cameras too, for obvious reasons, and they're prone to pull plugs willy nilly.
    Quote
    And I thought my setup was bulky......with only 2.5watt/hour drain.
    what camera do you use for your setup?
    I've been using Ixus 160s thus far and they're going well.  Picking them up on Gumtree for about $70 Aus.  So in total, excluding the enclosure: 
    • Canon Ixus 160
    • Raspberry Pi W Zero
    • 350 GIG hard drive
    • USB Hub adaptor - gives 4 full size USB ports
    • 12v to 5V DC to DC converter with dual USB outputs (2.5 Amps each output)
    LM 2596 Buck converter[/li]
    [/list]
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    Offline Mlapse

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    Re: Extended battery life for remote shooting
    « Reply #12 on: 28 / March / 2018, 02:36:14 »
    Quote
    When you say "your suggested batterie" do you mean the one I provided a link to, or is the 480watt batterie, a suggested size?

    I remember my dad telling me that watts = volts times amps but it's confusing how batteries are marketed as Amp Hours. 
    My novice math suggests that if it's a 12volt battery running an 8 watt device like mine, then it should run on a fullycharged 480watt battery for  480w /8w = 60 hours.  Am I right?
    two for two

    Amp is current draw, (like this 40Ah batterie can deliver 1200A crancking power)
    AmpHour is energy consumed per hour or capacity of your battery, like this 40Ah batterie holds 480 watt
    If there is somebody with technical english as a nativive language who knows better, please correct me.

    Quote
    If mains power is available at the location, would I be able to have it charging the battery too?  Experience on my first deployed rig tells me I can't count on continuous power.  Storms and people cause interruptions.  Construction workers are pretty anti cameras too, for obvious reasons, and they're prone to pull plugs willy nilly.

    if yu have mains power I would not work with a solar panel, but use a cheap charger of about 1A.....so not an off grid installation but a ups setup
    « Last Edit: 28 / March / 2018, 02:45:25 by Mlapse »
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    Offline Sdack

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    Re: Extended battery life for remote shooting
    « Reply #13 on: 28 / March / 2018, 03:15:47 »
    Quote
    two for two
    Awesome.. of course, 12v x 40ah = 480W
    Quote
    if yu have mains power I would not work with a solar panel, but use a cheap charger of about 1A.....so not an off grid installation but a ups setup
    so a 12volt charger at 1amp for 24 hours would recharge the battery by 288W, to replace our estimated 8w usage over 24 hours x 8w = 192 w.

    I guess cheap 12v chargers would have built in overcharge protection.

    Thanks again for your help.  I spotted a couple of spelling errors but I really didn't suspect that English wasn't your first language.
    Sdack
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    Offline Mlapse

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    Re: Extended battery life for remote shooting
    « Reply #14 on: 28 / March / 2018, 03:26:42 »
    no they don't have overcharge protection, they just lack the power to overcharge....if you discover that the batterie is drained use a >6Ah charger to bring it back to charged state

    something like this..

    https://www.amazon.com/Battery-PeleusTech-1A-Portable-Maintainer/dp/B01822CSA2/ref=sr_1_3?s=automotive&ie=UTF8&qid=1522231628&sr=1-3&keywords=Lead-Battery-Charger+1A
    « Last Edit: 28 / March / 2018, 06:19:03 by Mlapse »
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    Offline waterwingz

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    Re: Extended battery life for remote shooting
    « Reply #15 on: 30 / March / 2018, 00:21:00 »
    Quote from: Sdack on 28 / March / 2018, 03:15:47
    I remember my dad telling me that watts = volts times amps but it's confusing how batteries are marketed as Amp Hours.
    Watt, volts, and amps are all instantaneous values. Just like temperature or miles/hour.  They tell you what things are at the moment you measure them. 

    So if a 12v battery is sourcing 1 amp of current into a load, then it is delivering 12 watts of power at that moment.  If it puts out 3 amps then it is delivering 36 watts of power at that moment. 
     
    Obviously, in both cases it can't do that forever as there is only so much energy stored in the battery. The bigger the battery, the more energy it holds. So to help you determine how big a battery really is, they are rated in Amp Hours. Which means how many hours they can deliver the rated current at the rated voltage. 

    For example, if a 12V battery is rated at 60 Amp-hour, it will be able to deliver 1 amp of current @ 12V for 60 hours or 3 amps of current @12V for 20 hours. (Typically there is also a specified maximum amount of current it can deliver safely before it overheats internally)

    An analogy might be your car.  The speedometer tells you your speed but not how long you can continue to drive at that speed.   You need to know the amount of fuel in your gas tank and the fuel consumption rate of the engine to tell how far you can drive.
     
    Quote

    My novice math suggests that if it's a 12volt battery running an 8 watt device like mine, then it should run on a fully charged 480watt battery for  480w /8w = 60 hours.  Am I right?
    If your battery is rated as 480 Watt-Hours and it's a 12V battery, that's the same as a 40 Amp-Hour rating.  So it will provide 40 amps @ 12 V for 1 hour  or 1 amp @ 12V for 40 hours.  If your device needs 8W @ 12V then it will draw 0.66 amps so a 40 amp- hour battery will last 60 hours.  As you predicted.
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    Offline Sdack

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    Re: Extended battery life for remote shooting
    « Reply #16 on: 30 / March / 2018, 02:04:13 »
    Thanks for chiming in WW.. The fog is lifting.. the penny is dropping etc.

    My power draw calculations are a bit fuzzy because the only measuring device I had to hand was a cheap Kill-A-Watt like mains power device, which added to the chain of devices as follows:
    • 240AC Measuring device
    • AC to DC 12Volt 5Amp power supply
    • 12Volt DC to 5Volt DC, 5 Amp converter (out of a car cigarette adaptor)
    • Adjustable LM2596 5Volt DC to 4.2Volt DC Buck Step-down Power Supply Converter
    The measuring device states 'current wattage' which most of the time hovered at 8Watts, and there was a 'max wattage' which hit 12.5Watts, and a 'min wattage' which registered about 3.5Watts.

    I'm not sure if I need to account for the various lower voltages but it seems to me that the equation doesn't matter what combination of voltages and ampages are used, because Watts is consumption and that's WHAT matters (punavoidable pun)
    Cheers
    Sdack
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    Offline waterwingz

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    Re: Extended battery life for remote shooting
    « Reply #17 on: 30 / March / 2018, 11:10:13 »
    Quote from: Sdack on 30 / March / 2018, 02:04:13
    My power draw calculations are a bit fuzzy because the only measuring device I had to hand was a cheap Kill-A-Watt like mains power device, which added to the chain of devices as follows:
    So if your goal is to figure out how big a battery you will need then this part of your test setup :
    • 240AC Measuring device
    • AC to DC 12Volt 5Amp power supply
    is a "stand-in" the battery you will eventually use,  while this part
    • 12Volt DC to 5Volt DC, 5 Amp converter (out of a car cigarette adaptor)
    • Adjustable LM2596 5Volt DC to 4.2Volt DC Buck Step-down Power Supply Converter
    • camera
    is your field setup (once you add your camera to the chain of devices).

    This is workable but your measuring device is going to give you a very pessimistic measurement of the actual performance of your system in the field.  That's because it will show you not only what power the camera is using and what the two DC-DC converters ( 12V to 5V and 5V to 4.2V) are wasting BUT ALSO the power wasted in the conversion from AC to DC in your main power supply in step one.  Your Kill-a-Watt is measuring the input to the whole system when what you want is the input to what is actually going into the field.

    Still, while it won't give you a reading that is too low and cause you to underestimate your battery needs,  it could cause you to overestimate by as much as 100% (my guess).

    Also,  some of those 12Volt DC to 5Volt DC car adapters are pretty terrible from an efficiency perspective - you might want to find a way to go 12V to 4.2V directly if you can.

    Quote
    I'm not sure if I need to account for the various lower voltages but it seems to me that the equation doesn't matter what combination of voltages and ampages are used, because Watts is consumption and that's WHAT matters (punavoidable pun)
    Essentially correct as long as you are okay with potentially buying (and installing) a larger battery than you really need.

    EDIT : two additional thoughts
    • If your AC to DC supply is one of those that has a display of output volts and amps, take those readings and multiply them together to get the actual power draw (in watts) of your system. That will be a more accurate representation of what you need than what the Kill-a-Watt device tells you.
    • I think we covered it eslewhere, but knowing the maximum instantaneous current draw is important too. Your setup must be able to supply peak draw events like taking a picture, moving the focus or zoom mechansim, or recharging the electronic flash.  AFAIK, a peak capability of 2 amps (into the camera) should cover it.  Anything less and you start to risk "low battery" shutdown events.
    « Last Edit: 30 / March / 2018, 11:54:55 by waterwingz »
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    Offline Mlapse

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    Re: Extended battery life for remote shooting
    « Reply #18 on: 31 / March / 2018, 12:44:04 »
    • 12Volt DC to 5Volt DC, 5 Amp converter (out of a car cigarette adaptor)
    • Adjustable LM2596 5Volt DC to 4.2Volt DC Buck Step-down Power Supply Converter
    • camera

    I would advise to use the lm2596s to go from 12v to 4.2v since that means less system losses and you can do with a lighter 5v converter. most usb 5v cigarette adaptors are 2.4A or less
    « Last Edit: 31 / March / 2018, 12:49:07 by Mlapse »
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    Offline waterwingz

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    Re: Extended battery life for remote shooting
    « Reply #19 on: 31 / March / 2018, 12:50:05 »
    Quote from: Mlapse on 31 / March / 2018, 12:44:04
    I would advise to use the lm2596s to go from 12v to 4.2v since that means less system losses
    Agreed.  Something like this : DZS Elec 2PCS LM2596 DC-DC Step Down Variable Volt Regulator.  Just one example - there are hundreds of choices online using the LM2596.

    Quote
    and you can do with a lighter 5v converter. most cigarette adaptors are 2.4A or less
    I think you meant to say that "and your can do without a lighter 5V ....  ?
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