Edit: If you prefer to use AA cells. Read Part 2!
After having more and more of the original batteries for my gx680 failing over the last couple of years, i have now eventually fixed it. A few years ago, i modified a broken battery by replacing the cells with those of a pentax k10 battery. It has worked fine ever since and i now decided to make an adapter so that i can use those small and handy batteries directly instead of mounting the cells in the bulky gx680 holders.
Here is what you need to get 6 batteries and a mount.
- One dismantled original battery. It doesnt have to work, you need only bottom part to mount the new holder on the camera so that you dont have to modify the camera to fit the new batteries.
- Two sets of pentax batteries + charger, available on ebay.
- A soldering iron.
- Hot-melt adhesive or some other suitable glue.
- A drill with a drill bit of about 3mm.
Howto!
- Put one of the new batteries on charge with one of the new chargers.
- Dismantle the original battery and cut the wires away. If you want to be safe, keep the resistor, but i think its only needed for stopping the battery from overheating when charging with the original quick charger. You may get better capacity if you cut it away as well.
- Look at the battery mount on the camera, notice the third knob that looks like a connector. Measure out where the knob would be pushed by the original battery when connected to the camera. Drill a hole so that it doesn't push the knob. Test it by attaching the bottom. If it still pushes the knob or if it is hard to remove the bottom, then widen the hole until it works fine.
- Slide off the battery mount from the second new charger. Remove the bottom of the mount. Keep the part where you fit the battery and scrap the rest. Keep at least part of the wires, its hard to solder on the connector pins without melting the plastic. I replaced the wires in the new charger as i though they looked thin, but if id do it again i would at least try to use them anyway.
- Solder the wires + to + and - to - on the new holder to the original bottom plate.
- Test the camera with the charged battery! One of the following should happen: A: If you removed the resistor and the battery is fully charged, the camera should show a green led. I B: If you kept it, the led should be yellow (dont worry, you will still have lots of more juice in each battery than with the original ones). C: If only the lcd on the back shows the frame number, but the camera doesnt start, check your soldering! D: If nothing at all happens, double check that you soldered + to + and - to -. E: If the camera explodes, dont blame me! I have had one of these batteries working a few years without explosions.
- If everything works as expected, glue the new holder to the original plate!
- Charge all your six new batteries and go out shooting.
