measure the distance from the bottom of the battery to
the bottom of the band and the width of the
circumferential band. To remove the band, carefully peel
the strap from the positive terminal with needle-nose pliers
and slide the band off the bottom of the battery pack.
Properly dispose of the spent NiCd batteries.
To build a new pack, you will need four new C-size
Don’t waste the effort
using NiCd chemistry.
Most newer NiMH
batteries will work with
any charger designed for
NiCD or NiMH, and
there is no memory
The THS700 trickle
charges at about 50 mA,
so it can’t overcharge C-size cells.
Four C-size NiMH cost about $20 for 3,000 mAh
capacity (Fry’s Electronics and RadioShack.) This is about
50% more mAh than OEM packs! You will also need
about 8” of 1” diameter heat-shrink tubing.
Figure 3 shows the preliminary assembly of the new
batteries and the final assembly in the tubing. Slide the
new cells into the tubing (paying attention to polarity),
and trim the tubing to extend about 1/8” beyond the ends
of the assembled batteries.
While applying a slight pressure to push the
cells together, shrink the tubing carefully with a heat
gun. The new cells are likely fully charged, so take
care not to short anything!
The old band will not fit over the new shrink
tubing, so cut the band open near the point where
the circumferential ring strap is welded onto the
linear strap. Fit the band over the negative end of
the pack and locate it based on earlier
You want the circumferential strap to center on
the internal side
assembled. Use vinyl
tape to hold the band
in place, overlapping
the band by 1/8” or so
at either edge. Refer to
the photos, or better
yet take some of your
own prior to
Now comes the
only tricky part; see
Figure 4a for reference.
With the band
positioned at the
bottom, the strap must
be soldered to the
positive end button of
the top battery.
With a hot
soldering iron, quickly
wet the top button
FIGURE 2B. OEM
battery pack B.
FIGURE 2A. OEM battery
FIGURE 3. Rebuilt battery pack.
FIGURE 4A. Rebuilt battery pack
positive end view.
FIGURE 4B. Rebuilt battery pack
positive end view.
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20 February 2018