UK METAL DETECTING

austin · Joined: 30 Jun 2007 Posts: 65

I don't have a Tesoro, but one thing that amazes me is how they stubbornly stick with 9v batts, rather than go to 4x or 8x AA.

Perhaps a little controversial to say this, but 9v cells always say "toy" to me, and Tesoros are very far from being toys - quite the opposite from what I've read.

9v makes the machine a bit lighter, but that's about it.

Austin Smile

UK Brian · Joined: 08 May 2007 Posts: 431 Location: Wales

I don't like 9 volt cells myself but thats a hangover from the terminals either breaking off or going soft and a Garrett Grounghog I had that had its PP3's in a tray and some batteries seemed to swell slightly making them impossible to remove.

I seem to remember that in one of his early newsletters Charles Gifford said he preferred to use AA's because if one cell failed you didn't have to scrap the rest of the cells. That must have been around the Gold Sabre Mk1 time well before he got on the lightest detector kick.

I would prefer an AA pack under the armrest where the weight isn't really felt and it would help counterbalance the coil. Sticking with PP3's also means rechargable alkalines cannot be used.

rayredditch · Joined: 03 Jul 2007 Posts: 222

Problem with the 9volt rechargables is they are only 200mah.

Gary uk · Joined: 08 May 2007 Posts: 73 Location: Buckinghamshire

Last year we made some 6AA under arm battery packs for the Tesoro and Laser range, results were pretty amazing compared to the 9V system.....until some prat copied them

EdUK · Joined: 23 Jul 2007 Posts: 79 Location: Kent

What was different Gary when you used the AA pack as opposed to PP3 ?

malachite · Joined: 02 Jul 2007 Posts: 203 Location: The Toon

as far as i can see they only use em in the umax models and when u clag a duracell or energizer in it lasts for ever anyway so i dont see a problem.. except to say that they are becomin harder to find now.

Gary uk · Joined: 08 May 2007 Posts: 73 Location: Buckinghamshire

Hi I dont rate the 9 volt system and have found the 6aa conversion to be a worthwhile improvment over the original, especially if you hunt all day. The 6aa's will keep the machine much "fresher" for longer and maintain better long term performance.

Gary

mic.b · Joined: 01 Sep 2007 Posts: 17 Location: Southport,M.side.

Andy UK · Joined: 02 Jul 2007 Posts: 25

I used to do the battery conversions back in the early 90's on a few different machines, this was to balance out earlier detectors as they seemed front heavy, worked very well.
Don't you just hate copy cats ! Don't get me started !

UK Brian · Joined: 08 May 2007 Posts: 431 Location: Wales

mic.b
I would buy a good quality PP3 and see the difference. I think, though Gary is more likely to have a valid opinion, that Tesoro have gone a step to far with one cell, if you intend to use rechargeables.
Some machines only lose detecting time, others give reduced hours and just don't seem to work 100%.

rayredditch · Joined: 03 Jul 2007 Posts: 222

You come up with a good idea, get it patented, even adesign alteration, or improvement can be patented. Very Happy

Rabstar · Joined: 20 Nov 2007 Posts: 6

Can I be the only person who actually prefers 9Vs? They are smaller, lighter and it's easier to fit the spares in your pocket.

kered · Joined: 29 Sep 2007 Posts: 97 Location: NW Spain

i just recently bought 2 280mah rechargables and charger for my tesoro golden umax, the first one has just done 37 hours on its first charge, mostly on max sensetivity on the dry beach, highly delighted
baring in mind that they don't accept full charge for the first 5 or 6 charges things are looking pretty good.
They also seam to give full power till almost done rather than fade throughout the use

http://ukmd.informe.com/viewtopic.php?t=173

less than 17 quid including postage to spain and also a european adapter for the plug free of charge.
Same as item nº 300095592363 on ebay

UK Brian · Joined: 08 May 2007 Posts: 431 Location: Wales

The three things against PP3's were
(1) Some older machines had them pushed down into a tray system. When new it could be almost impossible to extract them, then, after time the connectors would splay leading to a bad connection. Other machines just had a wire with a connector on the end. These would suffer fatigue and cause either a bad connection or the terminal would fall apart.
(2) A single 9 volt battery often only provides just enough current so either you have a short run time or if modifications have been made the detector is lacking in sheer 'grunt'.
(3) Rechargable 9 volt batteries were/are around 7.2volts which did affect some detectors according to how the voltage regulation was set up.
(4) No rechargable alkalines available as with that type of battery each cell has to be charge as an individual and the PP3 is a joined block of single cells.

Most new machines now don't have (1), they get more depth out of less power now so the voltage required can be set lower which gets round most of (2) and (3). Performance from new, quality, rechargable NiCads/NiMH's is far better.

So with an older machine you might only get the best performance with alkalines.
The clue is if the manufacturer supplied rechargable kits. Fisher with some of their models warned you specifically not to use them. The rest should be fine though Gary did sell a battery pack to take AA's for some of the latest Tesoro range that was fixed under the armrest as a substitute for the standard PP3 set up. This gave a much longer running time and performance benefits as well.

Got to admit though the PP3, rechargable or not, is small and light so you can see the attraction.

Rabstar · Joined: 20 Nov 2007 Posts: 6

I have a Saxon SM40 which takes 8 AAs. When I am using it I carry a spare 9v PP3 which will run the detector for about 15 hours with no loss of performance.