Using a li-on battery .

[muddy fingers]

I have a detector which I rarely use which is fitted with a 12volt li-on battery. The battery is 3 cell and 2200 mAh capacity, producing 11.1 volts. I was wondering if I could fit it somehow to my old Toltec 100 detector which had two pods consisting of 4 ordinary 1.5 volt batteries so that each pod produced 6 volts. If I can't fit this particular Li-on battery, is it possible to swap the old ordinary 1.5 volt AA batteries for modern li-on batteries of an equal voltage or would they blow up or burn the circuit somewhere.

[Skippy]

The simplest solution is to get 8 cheap AA NiMH's (or even NiCads) and fit them in the two battery holders. No need for high-capacity types, especially if you're rarely going to use it.

The thing is, you don't know how the two 4-cell packs are wired up. Are they just in series to make a 12V supply, or is the 'centre-tapping' used in any way? This could foul up plans to run it on 3 x Li in series. Fully charged, 3 x Li cells would normally be 3 x 4.2V = 12.6V, so a good match for the 8-cell supply of the Toltec. Is you Li pack physically able to go into the Toltec, or are you just doing a cheap bodge with flying leads and some sticky tape?

[Tibuck19]

There are better experts then myself on here, your 3 cell 2200 are most probably 18650's which are 3.75V, So 3 of them would give you 11.25V or a Little more once fully charges, and that would run your Toltec 100 detector no problem, its a matter of fitting them in either with a store bought 3 Cell 18650 pack or a custom one if you can get access to a 3d printer.

[muddy fingers]

Thanks Skippy. Yes, I use Nicads or AA NiMH's but I don't like them in the Toltec as they don't seem to give enough power (each is actually 1.2 volts) and they just don't last for long enough.Each pod of four AA's that I use at present in the Toltec are wired up to a separate part of the circuit. The li-ons wouldn't fit inside the Toltec - I realise that but I was going to make some sort of container for them as opposed to just using sticky tape.

[6666]

You can buy 2600 maH AA NiMH's very cheaply these days

[Skippy]

It doesn't surprise me about the seperate wiring of the two 4-cell packs, a lot of electronics uses 'split' supplies, eg +5V, 0V and -5V, and it's not uncommon to power the headphone amplifier from just one pack, for example. You could make up two 5-cell NiMH packs, they would be almost 7 V when fully-charged, but would soon be down to nearer 6V, but of course they wouldn't fit inside the detector, you would probably have to use 6-cell packs with 1 cell 'bypassed', quite bulky.
And re: the previous reply, it's true, if you're buying 8 or 10 off cells, the price will fall. But if you already have 8 cells anyway, you can just buy another 8, and maybe two more holders for convenience, and swap them out 'in the field'.

[sinclairuser]

one solution is to buy some eneloop batteries these perform much more like 1.5v aa batteries, though they can seem expensive it is all relative, they can be found at a reasonable price but not buying aa batteries every time you go out hunting adds up, at current uk prices 4 eneloops cost about the same as 3 packs of Duracell, so on your 4th trip they have paid for themselves.

the 9v pp batteries are the same too, I have a cscope 770xd(for general hunting) this uses a 9v cell the rechargeable ones were terrible in this detector, one hours use would take the edge off the battery resulting in falsing and random beeps, just like when a standard alkaline cell is flat, so I used high quality alkaline cells in it but this was costing every time I went out with it.

the solution was given to me by a user on a scanner forum, rechargeable pp3 cells can vary a lot in output, from 7.4v, 8.3v and true 9v mine were only 7.4 volts at maximum charge so it was like using semi flat batteries, were the ones I got first which worked great, I then got some
from ebl which are the highest mAh I have ever seen for pp3's and are fantastic, these are also good , the plain unbranded ones are usually green or blue and are five pounds each from a uk seller on ebay just buy the highest mAh rated ones you can find, avoid brand names 90% of the branded ones are the lower voltage type.

[kt315]

http://www.geotech1.com/forums/showt...nter-discovery
from my post#8 and onward.

[muddy fingers]

Thanks for all the helpful replies. I think I will try it again using the 2600 maH AA NiMH's and see how that does. I'd hate to do anything that could damage the Toltec 100. When I look back at what I found with it, it obviously didn't miss much except perhaps tiny gold. I only found that once I began using the XP Powermax which runs at 18kHz.

[dbanner]

From this schematic i found, it looks like a straight 12V supply. So you should be able to use what you have suggested(11.1V zippy)

[dbanner]

Of course you would have to adapt the wiring from the two 4 cell packs which appear to be in series, if the schematic is accurate.