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Motorola 6 volt battery

PostPosted: 2014 May 21, 15:13
by wibs
This post covers the 6 volt battery used in the motorola mictac range and its derivatives. The battery pack has many different cells fitted to it both Nicad and NimH. They are usually the standard F7 size. I am in the process of rebuilding one from a FlaRe. The package number is SNN4612B 1B5103:GCD. It contains non-standard F7 cells. They are the standard length 17 mm and standard depth 6mm but are only 14 mm wide compared to the standard size of 17mm. They are a loose fit in the case but due to its internal shape the case will not take 5 standard F7 cells.

Re: Motorola 6 volt battery

PostPosted: 2014 May 21, 20:28
by oldmobil
Thanks for this useful info!
Hard to find working battery for Microtac family, so the only way to renew it. But without daily using the new cells will go bad within 2-3 years. So my idea to convert an old battery pack to holder for five replaceable Ni-MH AAA cells. I could charge these with my standard Voltcraft AA/AAA charger, and put them to the Motorola battery case when I want to test an old phone.
Maybe I'll not loose capacity because an F7 prismatic cells are around 700-800 mAh and a state-of-the-art AAA cell gives me 800-900 mAh.
I converted an Ericsson GH/GF/EH 197/198 battery to use AA cells same way:

Re: Motorola 6 volt battery

PostPosted: 2014 May 22, 05:10
by spectreman
Hi. I have several nicad & NiMh battery packs for the microtac phones.
I have managed to successfully restore about half of them.
Quite often when first used for a long time, the batteries will not start charging on the XT charger.
I kick start the packs by connecting a 6-7v DC power supply across the battery terminals for about 10 secs.
Must be a power supply that can deliver at least 1A.
Then I try the battery on the charger again, quite often it will start charging fine.
How long the battery pack will last for in use is another thing, some are very good, others only last a short time.
But better than nothing !

The best option though is to get yourself one or two lithuim battery packs for the microtac phones. You will need the correct EP charger for these though. And the lithium batteries are hard to find. But they last very well !

Cheers, Chris.

Re: Motorola 6 volt battery

PostPosted: 2014 May 23, 10:03
by oldmobil

Yesterday I managed to convert an old 6V battery to AAA holder. I had a late Ni-MH
battery (SNN4836A) what was a little bit thicker than standard SNN4102C Ni-Cd or
a standard SNN4239C Ni-MH. When I opened it I suprised, because I found five
AAA cells instead F7 like prismatic cells. (I used cutter, and opened it from bottom.)
I bought a four piece holder and a single holder for AAA cells and cutted their
bottom then glued with expoxy glue to the case. I soldered wires to the flexibile
pcb. I cut off the original thermal sensor of the battery pack, to save space
so I couldn't use original XT charger, but I can use my Voltcraft processor
controlled charger to charge AAA cells individually.


Re: Motorola 6 volt battery

PostPosted: 2016 Jan 28, 23:44
by Goochy
I need either new replacement batteries for motorola microtac 5200 and 7200 international or someone who can replace the cells and supply a new charger if needed. Obviously I am willing to pay. :D cheers

Re: Motorola 6 volt battery

PostPosted: 2016 Apr 29, 21:32
by TheMaritimeMan
Oldmobil, thanks so much for the detailed pictures. I have five MicroTAC batteries; all of them dead, and some of them starting to show corrosion on the terminals, meaning the cells have ruptured inside. I have a knockoff dremel tool, so I'm hoping to be able to cut all of them open and convert them to use removable cells.

Re: Motorola 6 volt battery

PostPosted: 2016 Apr 30, 04:16
by spectreman
This is a good way of replacing the cells in Microtac batteries.
I would personally replace the cells with solder tab nimh cells, not removable ones.
Then would use the original Motorola Intellicharge XT charger, which is ok for nimh cells.
You certainly cannot prise apart the Microtac battery packs, just end up breaking them.
Cheers, Chris

Re: Motorola 6 volt battery

PostPosted: 2016 May 03, 03:44
by TheMaritimeMan
Today I successfully cut open a medium-sized MicroTAC battery with my dremel. It was a clean cut with no damage, which is great. the medium-sized battery has five AA cells inside.

Now I need to figure out what I'm going to repack it with. AA's fit wall-to-wall, so I can't fit provisions for removable AA cells in it. I could fit provisions for removable AAA cells, but that almost seems like a waste of a larger battery. I might be able to fit one or two 9V batteries in there - I do believe these phones can handle 9V.

I guess the best thing to do really is to buy tabbed NiCD cells on eBay and solder them in. I had to destroy the circuitry that sat on top of the cells to get to them, though. It consisted of a resistor, a couple of diodes, and what I assume was some sort of thermistor. Is that circuitry required for the charger to work, or will it still charge properly? If not, I guess I can still charge the battery using an outboard charger.

So many variables...

Re: Motorola 6 volt battery

PostPosted: 2020 Feb 22, 17:38
by myr415
Indeed, it is difficult to accommodate NIMH type AAA with a diameter of 10 mm in an available depth of 7 mm! (Depth of the battery tray Ni-Cd SNN4102D MICRO TAC)
I had to cut the bottom to place the five NIMH AAA of 1800mAh :oops:

Effectivement, il est difficile de loger des NIMH de type AAA d"un diam├Ętre de 10 mm dans une profondeur disponible de 7 mm ! (profondeur du bac de la batterie Ni-Cd SNN4102D du MICRO TAC)
J'ai du d├ęcouper le fond pour placer les cinq NIMH AAA de 1800mAh !