Wondering about AA batteries versus 9Volt batteries?

[GeorgiaJay]

Hi,
I am new to metal detecting and this might sound kind of like a dumb question. I have noticed that some metal detectors like White's, Bounty Hunter, etc. use two 9 Volt batteries which equals 18 Volts (Total). While other metal detectors, like Garrett use four Double AA batteries. Double AA batteries are each 1.5Volts, so four Double AA batteries equals 6Volts (Total).

Does a metal detector that uses two 9Volt batteries have any more power, stronger magnetic field, deeper depth finding, or any other advantages over using a metal detector with four Double AA batteries?

[sectshun8]

Good question, I'm curious as well. The ACE 250, I think it takes 8 AAs... iunno, I haven't changed the batteries in forever so I don't remember.

[Vito]

Cann't speak for the Bounty Hunter's, but the White's operates at 9 Volt. The other one is driving the audio circuit.

MXT, DFX, IDX and XLT (may be some other, too) have 8 AA sized in a battery pack. Result is 12 V if batteries are used. If rechargeables are used there are only 9.6 V. (For that I'd build a pack of 10 AAA sized rechargeables .)

Some other detectors (china made) use two 9 V parallel to get more power of.

If I remember correct the earlier Garrett's used a bunch of 9 Volts batteries. But I dunno how they were connected.

You're correct by saying the voltage will drive the transmitted power.

But only to raise the battery voltage would be to easy. For best results you have to tweak transmission power and amplification of receiving circuits.

[Carol K]

Does a metal detector that uses two 9Volt batteries have any more power, stronger magnetic field, deeper depth finding, or any other advantages over using a metal detector with four Double AA batteries?

I don't think so. I would say... no.

The only difference I've noticed is that 9 volts cost more. lol

[foreverRich]

Welcome to our detecting family. One thing you don't have to worry about on this forum is asking "dumb" questions. If you don't know, just ask. As for the batteries, the nine volt batteries provide 9v for the transmit/receive and 9v for the audio. You normally get less detecting time with 9v versus multiple 1.5v batteries. So overall, detectors with 1.5v batteries are cheaper to run. At least that has been my experience, and I have detectors that use both.

[FelixtheCat]

I'll generally agree with the previous comment by ForeverRich - but also add that the design of the detector in how it uses power is probably the most important factor in how long something will last, regardless of the battery type.

[UK Brian]

Voltage and or battery type doesn't effect anything except run time of the detector nowdays.

In the past it could when voltage regulation wasn't so good or in the case of the couple of detectors with add on modules like the Treasure Baron where 8 AA's were needed to power the primary circuits if the passive boost in the coil was to be used the Deep Hunter circuit would have to be clicked in the back of the control box and it needed a secondary battery pack.
With Fisher CZ's two PP3's provided the needed 18 volts but the same circuit in the CZ 20 (the underwater CZ) was provided with four PP3's not because any extra power was needed but to increase the run time for a diver.

Funny thing re batteries and detectors is that while say a Sovereign will not function well with low batteries, some machines like the old classic Arados worked better as the batteries started to run flat.

[Dan B]

My first good detector was a Garrett Freedom 2 which used 3 9V batteries. It was costly to operate, and a pain to change the batteries, but I sure did find a lot with it.

Dan

[SkiWhiz]

When you say: two 9 Volt batteries which equals 18 Volts (Total). While other metal detectors, like Garrett use four Double AA batteries. Double AA batteries are each 1.5Volts, so four Double AA batteries equals 6Volts (Total).

It is not really how it works. Two 9 volts would be more than likely wired in parallel making the output 9 volts. If you put 4 AA 1.5 volt batteries in a battery pack the output is going to be 6 volts. It just depends on how the detector is wired. My wife has a Garrett Freedom Ace Plus that takes three 9 volt batteries, it isn't operating on 27 volts (3X9) it operates on 9 volts, by adding more batteries such as in my wifes detector for example it just makes the 9 volts remain longer. Steve.

[shawn]

It depends on the electronics. There are two ways to rig up 2 9v batteries. One is to output +18v and the other option is a bipolar supply with +9v and -9v. I looked at a lot of detector schematics and I'm do believe that the majority will be the +18 variety if they use it in that manner.

[zander10]

hi,

perhaps the detectors that require the 9v batts are less efficient electricaly then the ones that take AA.

it's just a guess but that is generally how electronics evolve. ie. more advanced device have lower power requirements.

my educated guess is based only on the two that i own (GTI 2500 AA batts and the F2 9V batts) and my experience as a computer scientist.


-zander