After years of chaos storing my rechargeable AA batteries, I realized I had to upgrade to a better storage system, and this is what I came up with.
The idea with this instructable is more to give you an idea for battery storage than to give you precise instructions for copying this one, although you are of course free to do so. Any piece of wood with 32 holes for batteries drilled into it will probably do much the same job.
Step 1: Features
The battery holder can accommodate four pairs of charged and four pairs of discharged batteries, in total 32 batteries.
When you remove a depleted battery from a device, it goes to the red section of the organizer, ready to be charged. After charging, it goes to the green section, ready to be used again. This way the batteries not only get stored neatly, but you also keep track of the charged and discharged ones.
Thanks to the handle, the unit is also extremely portable.
The only somewhat sophisticated feature the unit has, is that all the batteries rest on contacts (first photo) connected to a common measuring point (second photo), which means you can measure the charge of the individual batteries without removing them from the unit (third photo).
Step 2: General Construction Details
The total size of the unit is 225 mm in length, 95 mm wide, and 40 mm high, without the handle. The diameter of the holes for the batteries is 15 mm, and the distance between the centre points of the batteries is 20 mm.
I used two pieces of 16 mm chipboard for the upper and lower decks to ease construction, and also maintenance if necessary. The two decks also prevent dirt accumulating on the bottom of the battery wells. The lower deck is fixed to the upper deck with four wood screws from underneath. Note the two 6 mm nuts used with each screw as spacers between the decks (second photo).
Step 3: More Details
For the contacts I used common 2 mm thick 30 mm long nails (first photo), which were cut to a length of about 16 mm (second photo).
They were fixed into the bottom of each battery well through 2.5 mm holes drilled through the bottom deck. Their protruding ends were then soldered to wires (third photo), which eventually connect them all to the common measuring terminal (fourth and fifth photos).
I recessed the wires and solder joints on the bottom of the unit for a better appearance, but is probably not necessary. One can just use higher feet to raise the unit a bit, which should provide enough room for the wiring.
Step 4: Other Battery Sizes
Of course you can build similar units for other sizes of batteries. On the photo is one I built for AAA batteries. This one is just a storing unit because I don't use this size of battery as often as the AA's, and I also was a bit too lazy to go to more trouble.
Thanks for looking!