Solving Lemon Battery Issues: Cu/Zn, Voltage, Current

[gfisanick]

I am demoing a lemon battery made with a copper sheet electrode and a galvanized nail for the Zn electrode. I get a voltage of 0.954 volts from the battery which slowly decays over time.
Why is my voltage this close to the 1.1 V expected value if my concentrations of copper and zinc ions are so far from standard conditions?
Does anyone know the actual half reactions at work?
How can I increase the current from the cell other than placing several lemons in series? In other words, what is likely to be limiting the current?
Why can't I hook up multiple electrodes in series in the same lemon and get a higher voltage?
Why do texts make it seem like a salt bridge is mandatory in electrchemical cells when this example proves it clearly is not?

 

[chemisttree]

I am demoing a lemon battery made with a copper sheet electrode and a galvanized nail for the Zn electrode. I get a voltage of 0.954 volts from the battery which slowly decays over time.
Why is my voltage this close to the 1.1 V expected value if my concentrations of copper and zinc ions are so far from standard conditions?
Does anyone know the actual half reactions at work?
How can I increase the current from the cell other than placing several lemons in series?In other words, what is likely to be limiting the current?

Current will be limited by the size of the electrodes and the resistivity of the lemon.

Why can't I hook up multiple electrodes in series in the same lemon and get a higher voltage?

You can do just that.

Why do texts make it seem like a salt bridge is mandatory in electrchemical cells when this example proves it clearly is not?

The lemon is the salt bridge.

 

[gfisanick]

I thought the salt bridge was used to separate the anode and cathode so they could be in different chemical environments. In that case the lemon is not a salt bridge since the anode and cathode are in the SAME solution.

 

[JGM_14]

a salt bridge is used to separate the cathode and anode, but it can be in the same solution as well as different solutions also acting as a spacer between the two to keep them from shorting out like in conventional electrolytic capicitors
all batteries have "leakage" of current