of the battery, and brass nails or furniture tacks on the ends to make contact with the spring connectors inside the player. Attach wires to the tacks, make a small divot in the plastic cover to allow the wires to exit without pinching, and then wire it to about any source of the proper voltage (1.5 vdc, roughly, but anything from 1.2v to 1.8v will likely work without problem).
you can make a parallel-connected multi-cell belt pack, should run an mp3 player for many hours. make them rechargeables and add in a solar cell charger (one of the flexible sort that are coming out) and you've got a winner. (be sure to add some sort of provision for charging the rechargeables from the mains as well, since you might need to recharge more rapidly than the sun-charger will, or at night.) |
