A high-voltage DC power pack is what gives your Speedlight or Qflash the power to fire repeated flashes at very high rates. While you’ll still need ‘AA’ batteries in your Speedlight to power its internal electronics, an external power pack does all the heavy lifting. Changing your Speedlight’s ‘AA’ batteries will become a “once in a while” event rather than a few times per shoot.
Godox ProPac PB960:
• 11.1V; 4.5 amp-hours.
• about $122 USD, plus import duties; available from various eBay resellers (direct-import only).
Note that the Cyclone DR PP-400DR power pack (sold under the house-brand “Bolt”) is actually a re-branded Godox ProPac, except that it’s selling at traditional dealers for hundreds of dollars more than the what identical Godox unit sells for. The Godox ProPac sells for only about $122 from various eBay resellers (search “Godox ProPac” on eBay).
I know several of photographers who have switched from pricey Quantum Li-ion packs to the Godox units. They all report good performance, but with slightly slower recycle times than Quantum equivalents (e.g., a Quantum Turbo 3). However, some have also reported either poor battery life, spotty functional issues, or pre-maturely dead packs. They also come in three different colors: black, green, and orange. At these prices, you can afford to buy multiple spares.
Quantum Turbo (original model):
• sealed-lead acid (SLA).
• 8.0V; 3.2 amp-hours.
• replacement battery: Power-Sonic PS-832 (about $20).
The original Quantum Turbo power pack has been a staple among wedding, event, and press photographers for decades, and it’s now become one of the best buys in power packs thanks to a large used market. Not all photographers are aware that even a 20-year-old Quantum Turbo battery can be brought back to life for under $20 by simply re-celling it. Re-celling an old Quantum Turbo with a new Power-Sonic PS-832 breathes new life into an otherwise “dead” Turbo, allowing it to recycle as if it were brand new. Re-celling is simple, and you can find out how to re-cell your Turbo for less than $20 here.
Dynalite Jackrabbit II:
• Ni-MH; multiple AA-pack.
• DIY replacment costs only a few dollars (requires soldering, heat-shrink, etc.).
I also wanted to mention the Dynalite Jackrabbit II, since it’s also a fairly common item on the used market. It’s very compact, and great for powering Speedlighs. The Dynalite Jackrabbit II was originally designed to power the company’s AC/DC-powerable monolight, the Dynalite Uni400 Jr. But since its introduction many years ago, there have been many cheaper alternatives introduced into the marketplace (e.g., Vagabond Mini-Lithium AC inverter), making the Jackrabbit II a much less attractive choice.
Beyond that, the issue with the Dynalite pack is that, new, it’s simply over-priced. Also, if using it to power a 400Ws monolight, recycle times are in the 8-10 second range. Powered by a pack of standard ‘AA’ Ni-MH batteries (soldered in series), older Jackrabbit IIs can be re-celled for about $50 from a local BatteriesPlus. Or, if you’re handy with a soldering iron, you could re-build a pack yourself for just a few dollars.