Another option...
But first: IDX is right, there is a built in regulator in the machines that warns the user of a low level and then shuts down the machine when the voltage gets too low. Occasionally you get a goofball on one of the forums who wants to up the voltage from the pack to "Get more Depth". Doesn't work because of the voltage regulator, and other reasons, and you may damage your machine.
Fully charged pack voltage for NIMH is 9.8 volts- 8 cells x 1.2 volts per cell. Same pack with alkaline is 12 volts- 8 cells x 1.5 volts per cell. If you search the web you can see that different kinds of batteries have different discharge curves, you may not be getting that great of life from the Duracells even though they start from a higher voltage.
So....
Fill the alkaline pack with low discharge NIMH cells. When my original ML NIMH pack stopped holding a charge for any length of time I put high capacity NIMH batteries in an alkaline pack. Worked, but if the pack sat around for any length of time, as in days, they would discharge themselves to the point of not being usable.
I then switched to the low discharge type of NIMH cells. Charge them up, a year later they are still good to go. They cost roughly $2 a cell, and you get thousands of charge\discharge cycles from them. So.. between the second and third time you recharge they are already cheaper then the Duracells. $2 x 8 = $16 per pack. I believe I get around 20 hours of use from a pack; not as good of life as the RNB lithion pack, but way cheaper. And you can the same cells for everything else that uses AAs, I have a pile of AAA and AA cells and a Lacrosse charger, use them for everything, only buy 9V alkalines these days. Takes 30 seconds to swap fresh cells in to the alkaline pack, then you are good for another 20 hours. I have a couple of alkaline packs filled when I make a road trip, never run out of juice. With the RNB Lithion and Ukrainian 3D packs you can only use it in your specific metal detector and generally need a dedicated power supply to charge it, which of course would never get lost.
I bought a part for my Braun food processor from a Ukrainian 3d printing outfit, not sure if they were the same ones offering the Battery holders. Turned into a bit of an adventure. They wanted me to send funds by Western Union which turned out to be 4 times what the part cost. Finally just threw some US dollars in an envelope and mailed it off. Figured it could get stolen a couple of times and I would still be money ahead. Got the part on the first payment a couple of weeks later. Pretty crudely made, but worked, and saved me from buying a $60 new complete bowl assembly.
Chris(SoCenWI)
bigboyshobbies.net
