External Battery Box

[Sven]

You can do this with any detector that runs on 12 volts or less. Getting tired of coil heavy detectors with AA batteries in the control box? If you don't want to move the box under the s-handle, put your batteries there. This mod also works to increase your hunting time using a 12 volt recharge-able 4800mah Lithium Ion battery pack.

I original used two 4 AA cell battery packs that fit nicely in a project box fitted under the arm cuff.

PI's do tend to use batteries up faster than a VLF machine, figured it's going to cost more to operate in the long run using AA Alkalines. Pulled out a 4800mah Lithium Ion rechargeable battery pack purchased back in January. Did not think it would fit in the project box and it would not. Noticed the ribs on the box sides and 4 screw stand off on the bottom, took some measurements, pleased to find the pack would fit. Provided that the ribs and stand offs were ground away, which I worked on with a Dremel too.

Did mod the Lithium Ion battery pack a bit, ground out the epoxy plugs to access the 4 screws on the pack bottom. Removed the rocker on/off switch and replaced it with a 3 position on/off/on toggle switch. I didn't have any standard on/off switches on hand otherwise I would have used one. Kind of like the 3 position switch, center and left position are off, right is on. It will be harder to accidentally flip the switch on. Plus I have the on/off switch on the control box. Without having a speaker on the box, you really have to make sure the on/off switch is turned off when not using. When the battery pack itself is turned on, a blue light will glow thru the plastic covered hole in the battery box cover plate.
Next to the on/off switch is another hole, soon to have a cover plug. This is where the charger plugs in. Now if your wondering what battery connector plugs are pictured they are DEANS connector.

 

[Sven]

Here's another picture as I reached the max pictures allowed per post.

 

[Critterhunter]

I've got one word for you...LIPO! Much smaller and probably 1/3rd the weight if not more than 8AAs. A 3 cell series lipo will replace an 8AA pack (12.6V lipo). They are all the rage in my other hobby, RC electric planes, due to not only the compact size, but also the much lighter weight while giving higher capacity then nimhs or nicads. I'm running a $7 3 cell series lip in my machine using a $20 charger that will charge various battery types (nimhs, nicads, lead acid, lipos, lifes, and so on). The battery technology in metal detectors seems to lag about 10 years behind that of the RC crowd. I cringe when I hear how much people are paying for batteries and chargers in detecting. If you know where to look they are dirt cheap in RC. My little lipo uses a small plug and fits inside the regular 8AA holder. If I would ever want to go back to 8AAs I could set the little plug to the side and put 8AAs into the holder as normal. They also charge in an hour without pushing the battery, don't discharge on the shelf, and so on...Unlike nimhs or nicads.

By the way, you don't need a big deans plug for connecting to a metal detector. Those are meant for high (40 amp plus) power draws of electric RC planes and such. Detectors are very low amp draw. My machine (Sovereign GT) draws around 50 to 60 milliamps, so a tiny little JST plug is all that is needed.

 

[Sven]

Know all about those been into RC boat racing for years as well as RC sailboats, planes. Been there done that.
MY Radio Control Stuff
The Lithium Ion battery with charger cost $20 and is a 3 cell set-up inside the box.
As for the Deans connector being to large, yeah maybe, but they still are pretty small and had a bunch on hand from my electric race boat days when living in the US.
Use what I have on hand, as there are no hobby shops of any kind in this blasted small city I live in. Do you know what an o-ring is? Most people don't around here.
Only one place I found them here, at 75 -1.50 each that I used to buy for 15 cents. Up here you can buy a package set of different, non useful sizes in the toilet, sink area
of Walmart etc. Put, it this way, getting out of this city soon.... can't take it any longer. If you need something here, you won't find it, have to order 90% of everything in.