. . . using a standard soldering iron, and without damaging the batteries, such as with rechargeable C or D -size cells.
Sure. Pre tin the wires. Solder the positive of one battery to the negative of the next. Do the same for the other end. The voltage will be the sum of the voltages of each battery. 2 batt. 3V, 341/2V etc. Use the shortest time with the iron that you can to get a connection. Edit: Many commercial battery packs are made this way.
yes tin the wire solder it to the batteries, take the - side and solder it to the Next bat on the plus side , then + to - then - to + called in series 2- 1.5 bat wired like this will give you 3 volts
The metal used in batteries do not hold solder. You'll have to spot-weld the wires. They do sell battery holders of various sizes to get higher voltages. You can solder these wires together to get still higher voltages and or current capacity.
