Batteries and metal detector performance

[BH505Man]

It's been way too hot and dry to go out detecting and right now my coin count is down from where it should be at this point for the month in reaching my goals. The ground is way too dry and hard for digging.

So I was going through my notes and recalling my experiences on batteries and detector performance. While detecting I've noted a huge drop in performance when my Legacy 3500 battery charge indicater drops from full charge (4 bars) down to 3\4 charge (3 bars). At this point the detector tends to beep irratically at times and doesn't give accurate target information such as depth, target ID and the correct tone for the target(s) and it also doesn't ground balance or pinpoint as accurately. When I check the battery voltage at this point, I find that the voltage has dropped below 8.4 volts. If I continue using the detector, the performance continues to deteriate until the detector shuts down completely (this occurs somewhere close to 7 volts).

I found that only alkaline 9 volt batteries and the higher capacity (300 mAh and higher) true 9 volt rechargables perform the best. 300 mAh batteries will usually last for 2 to 2 1\2 hours of detecting while 450 mAh last about 4 to 4 1\2 hours.

I've found that my deepest finds and best detector performance occurs when I'm just starting out with a fresh set of fully charged batteries. I believe that battery state of charge is the biggest factor in over all detector performance.

 

[frankj3]

Walt,

You may have a problem with your unit. I have not noticed these issues when my 3500 gets low on battery voltage. The issue I have is once mine gets to 1 bar, I have about 10 minutes left on my batteries and then the unit shuts off.

I do not use rechargeable batteries. My owner's manual says not to use them. All I have used are "Copper Top" Alkaline.

I assume you are using your headset. I have never used my 3500 without them so I have no idea on battery life without using headsets. I can usually get about 30-32 hours out of my batteries using my headset. My last set did not give me that much time......but I think the unit being in my car trunk during this heat wave drastically affected their life. I have since taken my equipment out of my trunk and stored it in my house.

I would contact First Texas and discuss these issues with them. Good luck.

HH y'all.

Frank

 

[BH505Man]

No, actually my detector works fine. My Pioneer 505 is the same way.
It performs at it's peak when the batteries are at full charge and detects the deepest targets.

 

[BH505Man]

Your 30 - 32 hours sounds about right on the Duracell Coppertops. However, I'll bet that if you compare the performance of a new fresh set of batteries to a set that is partially discharged or down in voltage you will notice a drop in performance. That's why I always start out with a set of fully charged batteries. I can do that with rechargables. Normally I don't go out detecting for more than 2 to 3 hours at a time and I always carry an extra set of fully charged batteries.