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befus

Safari/flash Backpacker Power?

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Nearing completion of my first use of Ralph's Safari board, which I like a lot, btw. One question arises in my feeble mind (and I am sure I missed the discussion,,,,,but I'm old so bear with me.) Why the decision to use three AA's for board power rather than say a 9v? And how long can three AA's be counted on to power the board and flash backpacker effectively? NOT a fan of having to worry about replacing board batteries during the season. Just wondering as I wait for goop to setup and prepare to get the board and cam in the case. Exciting times :)

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Befus,

I believe the decision to use 4.5 volts for the Safari board was mainly to eliminate the need for a voltage regulator. If going above 5 volts a voltage regulator would be needed in order to keep from burning up the Picaxe chip and possibly some other components on the board. I have no data or feedback as to how long you can expect the AA's to run the Safari/Flash Backpacker but would expect at least several months. As you probably already know, there are several factors that will determine how long they will actually last such as weather, battery condition, how many photos taken with and without the flash, etc. If you are concerned about the use of the AA's you can add a Power Backpacker and use anything up to 12 volts to power the Safari board. FYI: a AA battery has 4-5 times the mAh capacity than a 9 volt so the AA's will give you a longer run time.

Edited by bigbassmann

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Befus,

I believe the decision to use 4.5 volts for the Safari board was mainly to eliminate the need for a voltage regulator. If going above 5 volts a voltage regulator would be needed in order to keep from burning up the Picaxe chip and possibly some other components on the board. I have no data or feedback as to how long you can expect the AA's to run the Safari/Flash Backpacker but would expect at least several months. As you probably already know, there are several factors that will determine how long they will actually last such as weather, battery condition, how many photos taken with and without the flash, etc. If you are concerned about the use of the AA's you can add a Power Backpacker and use anything up to 12 volts to power the Safari board. FYI: a AA battery has 4-5 times the mAh capacity than a 9 volt so the AA's will give you a longer run time.

Thank you sir. :)

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Ralph is right why we did not use 9v and a regulator. First thing with the board was to keep the cost down. Adding the regulator and circuit would have added additional cost to the board. The voltage for running the board without running a regulator is determined by the PIR sensor which has a minimum running voltage of 3v and the picaxe which has a maximum voltage of 5.5v. If we run with just 2 batteries at the 3v as soon as the batteries start dropping below 3v the pir sensor may stop working. Next battery up was a lithium ion battery at 3.7v and I thought that may be a bit confusing and would also need some extra circuits to make sure that the battery was not drained ruining the battery (which would add cost). So the next logic battery option is 3 batteries at 4.5v so that is what I designed the safari to run on.

 

The reason I was recommending the AA batteries was my estimates for power use was that AA batteries would last 5 to 6 months taking around 500 pictures a week. With AAA batteries the is cut in half with the same use.

 

The flash backpacker really adds no appreciable power load to the board and it is the code that make the biggest difference in power usage. Over a years time of running the board and flash backpacker the together (with the current flash code) it should only decrease the battery life by 3 weeks and that is all the 500 pictures being taken at night.

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Ralph is right why we did not use 9v and a regulator. First thing with the board was to keep the cost down. Adding the regulator and circuit would have added additional cost to the board. The voltage for running the board without running a regulator is determined by the PIR sensor which has a minimum running voltage of 3v and the picaxe which has a maximum voltage of 5.5v. If we run with just 2 batteries at the 3v as soon as the batteries start dropping below 3v the pir sensor may stop working. Next battery up was a lithium ion battery at 3.7v and I thought that may be a bit confusing and would also need some extra circuits to make sure that the battery was not drained ruining the battery (which would add cost). So the next logic battery option is 3 batteries at 4.5v so that is what I designed the safari to run on.

 

The reason I was recommending the AA batteries was my estimates for power use was that AA batteries would last 5 to 6 months taking around 500 pictures a week. With AAA batteries the is cut in half with the same use.

 

The flash backpacker really adds no appreciable power load to the board and it is the code that make the biggest difference in power usage. Over a years time of running the board and flash backpacker the together (with the current flash code) it should only decrease the battery life by 3 weeks and that is all the 500 pictures being taken at night.

Awesome Rick, thanks for taking the time to reply. See separate post for finished project.

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