New Zealand Gold Prospecting & Metal Detecting Forums Archive

post a photo of your battery, not sure what type you need, i know somewhere that supplies some types but need a visual

something like this battery??



JW :)

Hi Simon, I am not sure mate. These seem to work fine for me though. I run these in my Garrett Treasure Ace 300, Bounty Hunter Tracker 1V which both take 2 of them & my older Garrett Master Hunter which takes 6 batteries. My Whites GMT takes 8 AA batteries & these are also recargables & it seems to go all right with these. Finds me gold any way. It has its own rechargable battery pack as well.



I know the rechargables are a slight under the 9volts but weather it has an affect on depth or sensitivity, I dont know. The money saving on rechargables, even though they are pricey to start with, pays off in the long run.

Happy hunting

JW :)

Edited by user Friday, 22 July 2011 12:20:03 PM(UTC)  | Reason: Not specified

My Fisher manual says:

"The detector requires a single 9-volt ALKALINE battery. Do not use ordinary zinc carbon batteries. Do not use "Heavy Duty" batteries. Rechargable batteries can also be used"

I wasn't sure if they were worried about too much voltage or too little. I use cheap Dick Smith rechargeables which go 5 or 6 hours. A regular battery lasts at least twice as long.

A standard zinc-carbon battery cell puts out a maximum 1.5v
A NiCad (nickel cadmium) cell puts out max 1.2v

Hence a "9v" zinc-carbon battery will have 6 cells inside in series and out out 9v when new. (6 x 1.5 = 9)
A "9v" NiCad battery with 6 cells inside in series would only put out 7.2v when fully charged (6 x 1.2 = 7.2) which is not enough to be able to be used to replace a zinc-carbon 9v battery.

If they add another cell in series in a "9v" NiCad, they then get 8.4 volts (7 x 1.2). That's getting a lot closer. Yet another cell gets you 9.6 volts (8 x 1.2)

The trouble here is, although you're now up on voltage, they've had to pack those extra cells into the same space, so the cells themselves are smaller, which means the maximum current drain available will be less. So if your equipment will work happily at 8.4volts, you're actually better off using a NiCad battery rated at that, because in the end it will last longer in the equipment than a 9.6 v NiCad with less mAh rating.




Going up in mAh does not affect the equipment. If your equipment puts a drain of 100mA on it's battery, then a battery rated at 230mAh will last about 2.3 hours, and one rated a 280mAh will last 2.8 hours.

If the drain is only half that (50mA) then the 230mAh will last 4.6 hours and the 280mAh will last 5.6 hours.

Once you know the drain current of your equipment, you can then do some calculations to see if buying the higher rated batteries is actually worthwhile. The rating on the batteries could also be complete BS. especially if they're from China.

Also be aware that in order to fit more cell in there (to get the mAh up) they may have skimped on package thickness so the higher rated battery may be more prone to leaking if left too long in the equipment.

My wife came back from Florida once and had bought some AA batteries in a market, telling me they were much cheaper. I looked at them, and noticed that although they were the same colour as Duracell's, the brandname on them was "Durasell" or something, and from the weight of them I could tell they were nearly empty inside. They lasted about 1 minute in a toy. SO not that much of a bargain.

Mustn't complain though because she also came back with my Garrett GT2500. :)

Probably because the current drain of the equipment is high enough that those batteries wouldn't last long enough.

Hi Simon

I brought a couple of these 9.6v batteries they work fine in fisher detectors
http://ecobatteries.co.nz/mahaImedion9v.html

I also brought the 4 bay charger from this guy because it is a fast charger designed to work with the batteries I brought and it comes with a car adapter meaning that I could recharge the batteries travelling from one place to another.
http://ecobatteries.co.nz/mahac490f.html

And then I decided I wanted some extra batteries that if i got stuck somewhere for a while would give me a bit more power. I went for these because while they are 8.4v they provide 400mha of current so last a bit longer than less rater rechargeables, Oh and they cheap however shipping took 3weeks.
http://www.ebay.com.au/i...5646669d53#ht_1768wt_952

I honestly cant tell and significant performance over various 9v batteries ive used however the rechargeables dont last as long due to reduced current ratings. Despite this I am very happy with my choices and I have an armada of seemingly unlimited power supply.

Hi Oroplata

You can get rc helicopter 11.1v lithium rechargeable that are extremely snotty & cheap
But then you also need a balance charger and somewhere safe to store as if the lithium is exposed to air you have your own mini furnace/fire works display in a matter of seconds, this also happens if overcharged hence the balance charger.

I realize 11.1v is a little on the low side but with Lipo I really don't think that would matter.

i tried standard 9v rechargeable in my bounty hunter pioneer 505 and they didnt last long but found these on ebay so might give these a try.
http://www.ebay.co.uk/it...rksid=p3984.m1438.l2649.