Well I went and built a few Mock A123 Cells for Pack Designing before I commit to using the real McCoy. I'd much rather ruin a few cardboard mock cells than the real cells at $35 a pop. A few pennies vs lots of dollars. No brainer there. Now I have a way to build as much or little as I like and they will pretty much be the same as the real deal. The tabs are nearly exact. I was thinking that a large aluminum turkey pan for cooking your turkey would be a great source for the aluminum sheet for making the tabs for your mock cells. One large pan could provide quite a few. I got enough for 8 mock cells from a 9" pie pan. For the cardboard being a tad too think, I found that a rolling pin worked great for squishing them down a tad for a more realistic sizing.