5000 battery on sdc

has anyone tried using the small battery for the GPX machines on the SDC --like to see how u ventured..

since the sdc has an inbuilt voltage regulator built in--in all fairness it should work well.

just putting it out there.

regards
oneday

G'day Ray

Why not just use the 2 x 18650 Li and the adaptor kit, get much the same volts and much less mucking around, and works well.

cheers dave

I haven't heard of the 18650 li set up--bit backward up here..

regards
oneday

Fair bit of info about them in the link below Ray. We got our adaptors from Finders Keepers in Kalgoorlie, we just got the adaptors as we had the 18650's in a big torch and the charger so just got the adaptors.

http://golddetecting.forumotion.com/t24071-18650-battery-system

cheers dave

Dave,

What type of 18650s are you using? There's a couple of types - see the links. The internally self regulated ones are longer than the standard ones by about 5 mm at 70mm.

http://www.altronics.com.au/search/all/?sr=batteries

Scroll down to 2nd row. I reckon I can make some easy as. The problem will be a suitable charger. Working on it.

Yep the protected ones, like this, http://www.ebay.com.au/itm/161880854260?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

And using these 18650's and charger that came with a torch, keeps the SDC2300 humming along nicely. http://www.ebay.com.au/itm/Trustfire-TR-003-4-Slots-Battery-Charger-4PCS-18650-2400mAh-Li-ion-Battery-/222293810798?hash=item33c1be5e6e:g:KyAAAOSwUEVYEAbs

If you got some batteries that are 5mm longer and are making the adaptors yourself just make the length to suit, the total length just has to be the same as 2 x C size when they are sitting together end to end.

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cheers dave

just doing a bit of research and it appears these batteries have a quality control dilemma.

what is the main advantage over the 4 C cell batteries...if theres no real leap then I don't know what the excitement is all about.

my current batteries --c type originals-- last the best part of 6-7 hours of detecting time..this can be over 2 days depending on usage of course.

I usually time a battery changeover every 4 hours to be sure that the machine is getting a belly full of power to the coil.

there is a few vids on YouTube regarding the quality and the actual mah these batteries put out. The cheap $2 ones simply don't cut the grass, u have to opt for the $10 plus variety by all accounts..

so if I cant get a leap in performance with these batteries then i'm stuffed why people are having a go.

regards
oneday

Yes Ray the bit more expensive ones would be the better ones to go for.

Ok, one advantage is the 18650's are flat at around 6volts, they just turn themselves off, and the NiMh rechargables that come with the 2300 are fully charged at a bit under 6volts and drain down to around 4 volts before turning themselves off.

If the 2300 is self regulated internally to somewhere over 6volts to maybe 7volts, which I am told it is, (at least in the power to the coil) then the 18650's are going to supply maximum volts to the detector until they automatically turn themselves off.

All I know is they do seem to make the machine work better, real or imaginary, maybe it's just a feel good thing.

This would be exactly the same result as rigging up a GPX battery to the 2300 but it's way easier.

cheers dave

ok --will give it a go and see what happens..

regards
oneday

An internal voltage regulator works much the same as a pressure controller on an irrigation system.
It is intended to control the output pressure/voltage over a variety of input pressures/voltages.
At some input pressure/voltage the regulator will fail and blow the irrigation pipes/electronic components.
The whole point of having a regulator is to deliver consistent voltage to the electronics over a range of input voltages. To do this the regulator has to be set at a voltage below the input, which in the case of Nimh's will be 4.8 volts over most of their discharge life. A Nimh is usually considered to be discharged somewhere around 0.9 volts or 3.6 volts for the SDC. So we can guess that the regulator is set to around that value.
A common regulator is LM317 which from memory will regulate from 1.2v up to 36v (guess, as I haven't used one that high )
If one of these was used in the SDC (I don't know what they used this is just an example) you could plug the bloody thing into a 24 volt truck system and not alter the voltage the machine is using.
As for the voltage at the coil issue, the voltage will be controlled by another piece of electronics which boosts voltage to a preset level. With the regulator keeping the electronics at a fixed voltage and the booster keeping the coil at a fixed voltage the machine is smooth over the whole of the available battery as it discharges.
The key word is smooth, that is what regulators are put in there for.
Minelab may have designed this machine in some other way and not done these things, I don'y know, but this is the format that any respectable electronics manufacturer would follow.