Ni-Cad batteries

[Tesoro-CoinShooter]

I was using Enegizer Ni-Cad batteries for the last two months because I thought my owners manual said I could. I was re-reading my manual today and noticed that it said that when using Ni-Cad batteries always use a seperate convertible pack with the proper voltage output for the detectors desing. I have two questions about this - #1 - What is a converible pack? and #2 - Could I have dammaged or caused my Cortez not to perform as well as it used to by using Ni-Cads in it?

 

[jabbo]

I don't see how any damage could occur. Rechargeables are 1.25 volts. I use 1.25 volt NiMH batts in my detector. And I added two more to the outside of the battery housing, making it 10 total. Also added a jack on the battery housing for the recharger to plug into so I don't have to take out the batteries to charge them. I plug in the charger after each hunt and my battery graph always show full charge, even after the hunt is over. Been that way for about 8 months now and the detector works as it should. Don't know what a convertible pack is. Jabbo

 

[tvr]

Wouldn't expect any damaged.
How did the battery indicator read?

 

[Tesoro-CoinShooter]

When the Ni-Cads were fully charged , they seemed to read about 2/3 of what alkeline batteries do , plus they seemed to drain faster.

 

[tvr]

Info adds up.
Battery discussions can get very long and depend on specific priorities in an application ... Alkaline AA's start out at 1.5 volts, Nicads or NiMH are 1.2 to 1.25 volts at fully charged. The Cortez and the Tejon you are looking at use 8 AA's, probably in series. Alkaline means 8x1.5 = 12 volts to the detector circuits. Rechargeable are 8x1.2=9.6 volts. Jabbo gets the voltage back with 10 rechargeables in his pack. You can get higher capacity (milli-ampere-hour) at same voltage in the same size package as the Energizers. They would take longer to discharge and will probably cost more initially. There are a lot of battery choices advertised when you start looking at the electric powered radio control car, boat and airplane hobbies. There are also a lot of battery performance and trade-off articles available from those hobby areas. The car, boat and plane experimenters also test battery cell resistance and how it affects circuit performance ... there are books available ... that is part of where discussions get very long.

I don't know the circuit specifics, but one way to show battery level might be to measure how far above the circuit regulator cut off you are and to show low battery replacement level when you hit cut off. If the battery indicator shows batteries in the good range but not high, performance may be OK until the battery indicator says to replace the battery. To be sure, you may want spend time with the specific detector with alkaline cells and then some time with the rechargeable cells to see when performance drops off. Then you have more actual use information about what trade off you make by going rechargeable.

The Minelab Excalibur II uses a custom rechargeable battery pack. I've read reports that you must use the very expensive custom pack or alkaline AA's. Using rechargeable AA cells in the holder for the alkaline cells do not add up to enough voltage to run it. That may be along the lines of where the convertible pack note is coming from.

Got to run for now.
tvr

 

[BarberBill]

I haven't personally used the rechargables in my detectors, but have read where a lot of people do. I believe the detectors I own will operate just fine at the lesser voltage as it is above the point where the detector is dead in the water. However depending on the amper hour rating, they might hit that point sooner. That said, one of the main reasons I haven't used them (I do use them alot in my cameras etc.) is due to the fact that good quality alkalines last a good long time in my machines. Actually, if battery life becomes a problem for me I'll be very happy as it means that I'll have been detecting a great deal of the time. My two bits.
BB

 

[Tesoro-CoinShooter]

Thanks to all of you for your information.