1.. Here on the Metal detecting forum we are interested in how long a AA power-up a detector. If we used just ONE detector and shared it with 10 people, the same detector and coil, we could ask for their 'run-time; and ask them to monitor it. However, we would get 10 different answers. Some close but some might be longer or shorter than '
average.' Why? Because:
• Some wowuld use full Sensitivity and others might use little or moderate settings.
• Of the 10 people we could also have different Discrimination settings and that could effect the battery use and drain.
• They would be hunting different sites and engaging a few targets here and there for less drain, or they could be hunting a very trashy site and getting frequent hits on multiple targets, thus, different drain on the battery.
• Additionally, they wouldn't hunt until battery exhaustion with a fresh battery. Some would put in a 30 minute to 2 hour hunt and someone else would make a day-long hunt out of the time. Different battery drain and different periods for them to 'restore' a bit.
2.. Another consideration is that detectors take more than just 1 AA battery and we also know that we could check any battery pack when a detector is perhaps half-way through a set and, if we measured each battery individually, we'd likely notice some a little weaker and some a little stronger than what they all might '
average.'
3.. I have detectors powered by 2-AA's, 4-AA's and 8-AA's and it would be best to use a minimum of 2 'Tests' per 'set' of batteries. The AA alkaline battery has grown in popularity and I have at least 18 flashlights, of different brands and power levels [size=small]
(drain levels)[/size] here in my home, my vehicle, detecting gear tote, etc.. Some get used periodically and some just stand-their-post where I have them in case there is a power outage and they need to be used. I check them ALL periodically, but use the change from Standard Time to Daylight Savings and then back again to double-check them all. I look at their brightness and performance and then I inspect their batteries and test them ...
individually ... and if they are starting to get weak I replace the whole set with brand new batteries.
Back in the late '80s, when I worked for Compass Electronics, I had the time and opportunity to set up a test device just for the purpose of checking battery life. Used a design to hold a search coil in the device and turn it on to make a sweeping motion, back-and-forth, with the coil positioned about 4" above some test objects. An iron nail was used, a copper penny and a nickel [size=small]
(referring, naturally, to US coins)[/size]. That made the test samples the same, at the same distance from the coil and all search coils would be 'swept' across the targets at about a 4" distance.
All detectors would have a set of headphones plugged it, which is how most detectors are used, plus it eliminated the louder noise we could hear. The headphones were adjusted for full volume.
The detectors were adjusted for the highest Sensitivity level and the absolute Minimum Disc. level.
Thus, all batteries I tested were done using a metal detector set up at high Sensitivity and the lowest Disc. being worked continuously over three sample targets, one being ferrous,
In testing batteries, I started with fresh batteries, and didn't monitor the individual battery to a measured Voltage, but instead used them hard, without stop, until the detector [size=small]
(thus the batteries)[/size] simply quit and it shut down. I would then remove the batteries at the time the detector stopped working and measured each battery. I made note of the total continuous 'run-time' from start-to-stop. Also, since I didn't have a set-up to test each individual battery during the testing process, once the detector died I would measure each battery and note the Voltage level.
I would 'Test' each brand of battery twice, and then
'average' all of the data.
Start-to-quit operating time, Divided by 2, for running the test twice, to get an
'average' of the particular battery brand and model and expected
time of serviceable operation. Let's say the detector was powered by 8-AA batteries of Brand R and it ran for 44 hours. Divide that by the number of batteries [size=small]
(
[/size] and we see each battery
'averaged' 5½ hours of run-time. But if a different battery, Brand N also ran it for 60 hours with just 8-AA batteries, then those batteries
'averaged' 7½ hours of run-time per battery.
Then you can compare the
'averaged' 'Run-Time' of the different battery brands, and from that also figure in the cost for those individual batteries.
I know that back then, 31 years ago, I tested some off-brand Heavy Duty batteries that out-lasted and cost less then the worst 'popular-brand' Alkaline and that was Ray-O-Vac. Those used to be the worst and, to this day, I still don't buy that brand. Today we have a ot of often-used Alkaline batteries that provide very good service life and can be very affordable as well. I have also found a less-known brand battery with comparable life at a lower cost which are often made by a major battery manufacturer.
The benefit of that testing I did is that it wasn't putting an artificial load on the batteries, but was an actual test using a metal detector and coil, with comparable settings, and operated continuously over test targets and that made the battery use more comparable. And with even more brands and models made today than back then that operate on AA batteries, you could run 2-tests for each brand and model detector, then compare not just the battery efficiency per battery, but also compare the operating efficiency of different makes and models of detectors.
Just some thoughts, and I considered doing this kind of test this winter but would need to buy a camera and stopwatch/clock to be able to look and see the time it was when the detector shut-down as the battery supply died.
Monte
