Minelab GP Extreme tips, settings, questions

[GaryO]

12 v at 10 AH running 6 volts will outlast a 6 volt 10AH battery at 6 volts.
Plus the the 6 volt system starts dropping voltage and performance from the moment its turned on ..
A regulated 12v system voltage stays at the set voltage until the 12 volt battery drops below the set limit.

Gaz

I know exactly what your saying Gary0, its a shame my regulator doesn't have a voltage read out so I can check and make sure the volts don't exceed the sweet spot. I can check the voltage though coming out of regulator so I suppose if that's pumping out the required amount then a read out is not needed. I don't mind carrying a bit of weight so the 12v as long as its not damaging anything will be my choice and use the original 6v as a back up.

Just make 100% sure that it is set up and regulated right otherwise use the standard set up until someone can check it out for you . But a multi meter will tell you what the output voltage is set at .
Post a pic of the bits may help as well.

As for the noise when testing , definitely power lines etc. so don't panic

 

[condor22]

12 v at 10 AH running 6 volts will outlast a 6 volt 10AH battery at 6 volts.
Plus the the 6 volt system starts dropping voltage and performance from the moment its turned on ..
A regulated 12v system voltage stays at the set voltage until the 12 volt battery drops below the set limit.

Gaz

Agreed, however Rejy's 12V is only 7AH. If you look at the Wattage of a complete charge 6V x 10AH = 60W. The 12V would be 12V x 7AH = 84W. Then there is the efficiency drop of converting 12 to 6. So there is very little gain in actual AH capacity.

However, I totally agree with the regulated 12V giving a stable 6V for much longer, which is the main reason people do this. Once the 6V battery is 50% used its V will be nearer 5.5V, but the 12V regulated will hold 6V output until there is no longer enough charge to run the regulator chip/transistor.

I wouldn't want to go much below 50% depth of draw on either battery as doing so will reduce battery life.

When I'm out with the 5000, I put the battery on charge from my 4x4 auxiliary battery at lunchtime. I doubt I've ever run any more than 25%.

 

[GaryO]

True Condor

 

[Rejy]

Can I use the original coil or should I purchase another and if so what?

 

[blisters]

If it's a linear regulator then you'll get 100% power loss converting the12v to 6v and you'd be constrained by the battery capacity. I'd be surprised if it's a switch mode regulator but even if it is I can't see any advantage to the extra complication over a second properly sized 6v battery. The old KISS principle comes to mind

A 6v battery will be a little above 6v at 50% discharge and at 6.2v at 30% discharge. The 6v is best suited to the task as with fewer plates it is more reliable and they can be made thicker increasing capacity for the same external dimensions and weight as a 12v.
Jon

 

[Jaros]

KISS is usually the best. Sometimes we over-complicate discussions and it leaves out the members with little knowledge of these things. I can see their eyes glaze over reading some of the topics that come up on the Forum.
Jaros

 

[Rejy]

Yeah it's a very common mod for people, so for it not to make a difference doesn't make sense. I'll take some photos tonight.

 

[blisters]

The only thing I can think of is it's regulated at a higher voltage say 8v and this punches a stronger field into the coil increasing sensitivity. On a second read I think this is what mbasko was saying.
Jon

 

[mbasko]

The reason people use the 12v & a regulator is to maintain a constant voltage of their choosing. Like I said earlier most seem to agree around 6.8v is optimal for the GP series & the Coiltek pocket rocket aftermarket battery was switchable from 6.7v for GP's to 7.2v for SD's. A lot of people do choose to run GP's at the higher 7.2v or thereabouts & believe they do get more out of them? Personally I'd be very reluctant to run much above that (7.2v) & know that they will shutdown at a certain point anyway & possibly could let the magic smoke out of something.
I am also led to believe that the camcorder type batteries from Detectormods to suit SD/GP series detectors are regulated at 7.2v. I have used these on a GP3500 with no ill effects as I'm sure many others have.
Using bulky 12v or even 6v gel batteries is pretty much a moot point now with the camcorder type set ups & many dabbling with regulated li-ion or li-poly set ups which are lightweight.

When I'm out with the 5000, I put the battery on charge from my 4x4 auxiliary battery at lunchtime. I doubt I've ever run any more than 25%.

A lot do this but from what I'm led to believe (from smarter blokes than me) is that there is no real reason or benefit in doing it unless you plan on doing 12hr plus days. The GPX batteries are fully charged at 8v plus & will maintain an input voltage of above 7.1v (shutdown voltage) for up to 12 hours. These smarter people have explained to me that the GPX is internally regulated to run optimally somewhere around or just above this 7.1v shutdown hence the shutdown & the safety factor of li-ion battery "low level" is factored in with that as well.
I never run my GPX battery down to even a low level warning over some long days out & used to just recharge every night. Never had any battery issues doing this but if something works for you then stick to it I guess.

 

[Rejy]

So I took a photo and realised I couldn't post it due to being too large. I opened it up and there doesn't seem to be any adjustment options, though I think this is good. I tested volts coming out and it was 6.84v on a fully charged 12v battery.

 

[condor22]

I base my comment re the 5000 battery, not because of its regulated output, but for the management of a Lithium Battery.......

 

[Rejy]

I was looking at the 14" Dd coil tech and the 15" detech ultimate spiral coil. Does anyone have any thoughts.

 

[Heatho]

What detector are you running? Are you near a built up area or in the country? You will need a DD if you are anywhere near a city or town or electronic interference. I've used my 5000 on Sydney beaches before with the standard 11"DD without the salt timing, if you go near the wet sand you will probably need to use the salt timing.

The minelab coils are not waterproof either, I think the coiltek ones are though but make sure to check first.

 

[Jaros]

I wonder why the minelab coils aren't waterpoof. They aren't cheap.
Jaros

 

[PhaseTech]

I'd recommend the Detech 15x12" DD Sef. Fully waterproof, open web so doesnt trap sand, good ground coverage, deep, works great with Cancel mode, Salt etc

 

[Rejy]

Sorry for lack of information. I'm in a built up area (Newcastle) . I'm using the gp extreme with original 1100dd coil (lots of interference in back yard playing). I just bit the bullet anyway and went for a detech 15" ultimate spiral coil this is water proof too not that I'll be needing it. Can't wait.

 

[Detrack]

Hi All

I used the regulated 12v system on my 2100 to my 3000 and it was the best way to go make the Detector run so much smoother and could run it for a day and a half at 8v which is what I had mine set at.

extra good if your using big coils for good strong RX-TX

Cheers

 

[Rejy]

Best price and where. It's for a Gp Extreme or has anyone made their own handle.

 

[vstrom]

EBay I think I saw after market One's for $38 with ground grab button .

 

[old hand]

This is one I made for a 3500