Proprietary battery pack

[Hondaman]

Hello,

I hate to ask this question, because there is no easy answer. Basically, I have a proprietary battery pack. 3 AA batteries sitting on top of 4 AA batteries, glued together. I need a "tab welder" to reproduce this. But I don't really know what settings I would use.

Basically, it is the battery pack from a Scientology E-Meter ("John Travolta Space Cootie Detector"). I got it for journalistic, research and hilarity purposes. Only about 40,000 of these units were made ("Quantum Mark 7") so I suggest a new old stock exact match is out of the question.

I found a couple of 8.4V battery packs online that really might work (3 cells on top of 4 cells). But they are lithium-ion. Will the battery charging circuit inside the meter be able to handle the different chemistry / capacity?

I apologize that I can't give any real info about the charging circuit, except it takes a 5-volt barrel plug from a "wall-wart" AC adapter plugged into the back of the space cootie detector. Any thoughts?

[petehall347]

Re: Proprietary battery pack

replace with single tabbed cells . they solder in .
https://www.cs.cmu.edu/~dst/Secrets/...intenance.html
https://www.cs.cmu.edu/~dst/Secrets/E-Meter/Mark-VII/

[eccerr0r]

Re: Proprietary battery pack

is the pack simply 7S or is it tapping different voltages from it?

I suppose if you have protected li-ion packs and it's simply 7S with no taps, you could just do 2S protected lithium ion. The protection on the li-ion hopefully will prevent the incompatible ni-cad charger from making the li-ion explode.

[Hondaman]

Re: Proprietary battery pack

I'm seeing some NiMH AAA battery packs online in the "hump" configuration (3 cells on top of 4) (might be the same battery as the Snap-On MTG-2500 scanner for diagnosing your modern car's sophisticated electronics). The battery has a thermostatic switch inside the cells that cut off power (presumably for both charging AND discharging) at 55 degrees Celsius. Is this the kind of protection I need?

The NiMH cells are around 750 mAh or 800 mAh, very close to the Ni-Cd I took out. Is the meter's internal charger really not compatible with NiMH?

BTW: Older E-meters power some of the meter with 6 cells and part of the circuitry uses all 7. I have a later design -- Only two wires come out of the battery shrink-wrap, so I presume all of the meter uses all 7 cells.

Will this battery type be a problem for this charger? Do let me know.

[eccerr0r]

Re: Proprietary battery pack

I suspect the 7S configuration (make sure you don't have any taps in the pack!) is used when the circuit was designed for a PP3 battery and then found out it doesn't last long enough...

The comment is to indicate that the internal charger is incompatible with lithium ion. If you're replacing with nickel batteries, this isn't a concern.

However NiMH cells use a slightly different charge algorithm than NiCd. In this case it looks like it has a dumb charger so it probably doesn't make a difference.

[Hondaman]

Re: Proprietary battery pack

I got a 7-cell pack online (AAA NiMH batteries) in the "hump" configuration and a standard connector. I found a suitable connector from an old tower computer that I scrapped, and soldered the wires right in. The meter seems to charge and run just fine. As you can see, I'm ready to start auditing the space cooties away. With plenty of the same beverage that the dear leader David Miscavige drinks !

[stj]

Re: Proprietary battery pack

so it's a glorified lie detector, a galvanic meter?

[Hondaman]

Re: Proprietary battery pack

Yes. It was originally developed by a chiropractor, Volney Mathison. I have no idea why he thought this was appropriate for use in his field. Then when L. Ron Hubbard got into an argument with Mathison, suddenly LRH denounced Mathison's meter and you could only use LRH's meter, which (like everything else in Scientology) is rigged to give maximum financial gain to the organization.