Flex Stacked Lithium Battery

Apr 04, 2024

The power tool world is learning about the benefits of lithium-ion pouch cell technology. The Flex Stacked Lithium battery takes advantage of that tech and sends it to a whole new level.

Pouch cells open up the possibility for more than just a different form factor compared to round cells. Connection tabs open up far greater energy flow, resulting in higher power output and faster charging without producing dangerous levels of heat.

How much of a difference does it make?

According to Flex’s data, it’s massive. Just look at this chart from the Flex Faceoff Round 2 video.

First of all, keep in mind Flex uses a 24V max system based on rows of 6 cells instead of 5, so there’s already an advantage built-in. Even so, two things stand out from this data. First, Flex’s compact 3.5Ah battery is producing the same power as DeWalt and Milwaukee’s 8.0Ah packs.

At the top of the chart, DeWalt and Milwaukee top out at 1800 watts—exactly the maximum power you get from a 15-amp, 120-volt circuit. Flex jumps all the way up to 2520 watts, giving the 10.0Ah pack potential beyond any 15-amp corded tool. In fact, it’s more than a 20-amp, 120-volt power source can provide.

Check out how Flex Stacked Lithium batteries compare to their standard ones in terms of power:

Additionally, these packs can charge up to twice as fast and last up to three times longer than round cell packs, all while remaining 100% compatible with all Flex 24V tools.

With the 550-watt dual fan-cooled Flex Super Charger, here’s what you can expect for full charge times:

While the cell itself opens up significant doors, there’s more to the story. You can’t just slap some pouches in a battery housing, install it on the tool, and hope for the best.

Flex has impressive heat management from what they call ThermaTech Plus. It allows the cells to dissipate heat more effectively than other brands. The design also offers some cushioning that reduces the risk of failure if you drop the pack to the ground.

Add in electronic monitoring of each cell with advanced communication to the tool and you have a battery that’s safe to use in demanding applications with far greater productivity than standard round cell packs.

Look for individual and multi-packs, starter kits, and combo kit packages with Stacked Lithium batteries to roll out over this year. Here’s what we expect the individual prices to run:

The additional power potential coming from smaller batteries is really exciting. When you add in faster charging and a much longer service life, the transition to Flex Stacked Lithium batteries is one that makes a lot of sense and opens the door to all-new levels of power tool performance.