Wiring Up 100 Car Batteries So You Don’t Have To

We’re willing to bet most Hackaday readers have accidentally spot welded a few electrical contacts together over the years, complete with the surge of adrenaline that comes with the unexpected pops and sparks. It’s a mistake you’ll usually only make once or twice. But where most of us would look back at such mishaps as cautionary experiences, [Styropyro] sees an opportunity.

Armed with 100 car batteries wired in parallel, his recent video sees him pitting an assortment of household objects against the combined might of eighty-five thousand amps. Threaded rods, bolts, and angle iron all produce the sort of lightshow you’d expect, but [Styropyro] quickly discovered that holding larger objects down was more difficult than anticipated. It turns out that the magnetic fields being generated by the incredible amount of current rushing through the system was pulling the terminals apart and breaking the connection. After reinforcing the business end of his rig, he was able to tackle stouter objects such as crowbars and wrenches with explosive results.

A modified log splitter serves as a remotely operated switch.

We found that his remotely operated switch, built out of a hydraulic log splitter, to be a particular highlight of the video — unfortunately he only briefly goes over its construction at the very start. His side experiment, fashioning an sort of manually-operated carbon arc lamp with a pair of thick graphite electrodes and demonstrating is luminous efficacy compared to modern LEDs was an unexpected treat. As was the off-the-shelf domestic circuit breaker that impressed [Styropyro] by refusing to yield even after repeated jolts.

While the showers of sparks and vaporized metal might trigger some sweaty palms among the audience, we’ve seen [Styropyro] handle far scarier contraptions in the past. Though he may come off as devil-may-care in his videos, we figure there’s no way he could have made it this long without blinding or maiming himself if he didn’t know what he was doing.

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Doubling The Capacity Of Power Tool Batteries

YouTube User [Vuaeco] has come up with a novel idea, combining power tool battery packs to double the capacity.

Starting off with two slimline 2.0Ah compact battery packs, [Vuaeco] wanted a larger 4.0Ah rebuilt drill battery pack. These battery packs are different in size so it wasn’t just a case of adding in more cells in empty slots, instead he goes on to show us how to connect the batteries in parallel using some thin nickel strips. Once completed he modifies the battery casing so it fits another stack of batteries. He does this by bolting the top and bottom together with long screws, and insulating the otherwise exposed battery terminals with insulating tape. The final product isn’t as aesthetically pleasing as a real battery pack, but it looks good enough.

There are a few things we might have done differently, for instance providing some hard plastic around the insulation so should the battery get knocked in an awkward position it would still have a hard shell protecting it. Also, instead of combining the batteries together fully charged as the video suggests, we might have done the opposite approach and fully drained them, avoiding unnecessary risks. If you try this, how about giving it a 3D printed case?

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