LR20 Battery Holder Conversion Kit 40mm tube with 12V cap

thingiverse

I'm gearing up for my camping trip without a single plug for my power-hungry gadgets. To keep my smartphone, tablet, and Bluetooth speaker juiced, I need a massive capacity battery pack that can keep pace with my needs. A large LR20 (mono, type D) alkaline battery pack packs 18,000mAh according to Wikipedia, and I just so happen to have my trusty car charger on hand. I didn't want to splurge on an expensive 12V lead-acid system for this trip alone, and besides, it would end up collecting dust once I got back home. Plus, LR20 batteries can be recycled responsibly, which is a big plus in my book. To create a makeshift 12V outlet, I fashioned a 40mm outer diameter tube into a battery holder using two M4 screws. Then, I attached it to a standard 12V outlet box and hooked it up to my car charger. The cost breakdown is as follows: 23 euros for 20 LR20 alkaline batteries (purchased on Amazon) - it takes eight of these batteries to hit the 12V mark. For just under 9.2 euros, I can recharge my phones four to six times, which suits me just fine. To assemble this nifty contraption, simply screw in the M4 screws into both the cap and the bottom. Next, cut the tube down to 48.8mm. Glue all the parts together (excluding the cap), then screw it on securely. Be sure to keep an eye out for short circuits - we're talking several amps here!