Brian, what thickness of aluminum are you using for your battery holders? I may try your technique with some 1/8" thick polycarbonate, and then use heat (torch) to soften the plastic enough to be able to bend the tabs.
SH Z-Car, Custom Crawler, 8s Savage, 12s XTM XLB 1/7 buggy, 4wd 4-link rear/IFS Pro4 truck, Custom Hyper 10 Short Course, Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz
I'm using 1/16" thick 6061-T6. I was going to look at using plexi/ploycarb, but wasn't sure how it would stand up to track (read: crash) abuse. I was afraid it would crack with the sudden stresses.
It'll be interesting to see how that works. I'm just too chicken when it comes to protecting my lipos.
BTW: I was playing with some 1/16" polycarb/lexan/plexi and a heatgun works very well to soften it enough to bend. Gotta be careful though, because it seems to heat very quickly; one minute it's too stiff to bend, then a second later it's all but a puddle. Funny how that works...