New cement batteries.

I've made a group of new cement batteries last weekend in different sizes and with different chemicals added:
two large Red Bull can batteries(or to be precise : cells):
1.19 V with copper tube
1.27 V with copper strip
one Monster can battery
1.13 V
one energy drink can battery,Alum added:
1.15 V
four Coke batteries:
Magnesium sulfate added:
1.16 V
Borax added:
1.29 V
Alum added:
0.5 V
Copper sulfate added:
1.07 V