Help...?????

[freeze12]

Maybe someone can help Me with this: I have a metal Detector (Minelab Quattro) & I am trying to figure what size nimh batteries to put in the slideout battery holder that come with the unit.
The holder holds 8 AA batteries originally (4 side by side) eqaling 12V
Because 8 rechargeables do not have enough power for the unit.
What size nimh AA battery do I use in this holder (10 batteries 12V) to equal the power I need for this detector?

Thanks!!

 

[gadget_lover]

Dan, I'm not sure what your question is. YOu say it uses an 8 cell battery carrier, but you want to stuff 10 cells in there?

Most devices will work within a range of voltages. Nimh will start around 1.4 volts per cell, and drop over time. While 1.2 volts is usually considered the nominal voltage, the chart at http://www.thomas-distributing.com/maha-charts.htm shows that at lower current drain it's closer to 1.3 volts.


According to http://www.duracell.com/oem/primary/alkaline/alkaline_manganese_over.asp,

[ QUOTE ]
he open circuit voltage ranges from 1.5 to 1 .6V, depending on cathode formulation. Typical median operating voltage ranges from 1.3 to 1.1V under moderate discharge conditions.

[/ QUOTE ]

Have you tried NiMH in the device yet? If it does not work with 8 cells, I'd go no more than 9 cells (13 max, 11.7 average).

Electronics do NOT like to be overdriven.

Daniel

 

[freeze12]

gadget: The unit right now operates on 8AA Alkaline AA's which equal 12 volts.My problem is finding rechargeable nimh's (10) which equal 12volts that will fit in the tube & has approx the same length or a little shorter than the alkaline aa's.the 4/5th A rechargeable are the closest I have seen but still come up short even installing a dummy AA battery.

 

[gadget_lover]

Ahhh. Now I see. Have you tried 8 AA Nimh yet? The draw from a metal detector is not too great, if I recall correctly, so the voltage should hit between 1.3 and 1.4 per cell.


Is the battery carrier a straight tube that fits into the shaft of the detector? A "dummy extender" can be made from a wood dowel and a length of wire or a simple bolt with tape wrapped aroud it.

Daniel

 

[Starlight]

Freeze12, forget the rated voltage. Try 8 AA rechargeables first. You may not need 12v for it to operate properly.