Marginal heat, but comfy...
This coat is a bit of a disappointment. While it was purchased it for some early-winter work on the exterior of a house (in a relatively mild northwest U.S. coastal location), it seems more suited to a mid-autumn stroll on a cool day.
Even set on "high," the heat is barely detectable in the two upper chest heating zones, with the mid-back zone a bit more noticeable. (It's difficult to imagine the heaters being of any use at all on "medium," much less "low.") The coat is, however, comfortable, and with suitable insulating clothing underneath, it may actually be about right (when set on "high") for moderately hard work outside (when the body itself is also contributing heat) in temperatures from the low twenties (F), judging by initial experience with the coat. (UPDATE: After a few more days' experience, it has become apparent that although "high" heat is far from overwhelming in a cold outside setting, it can become rather hot on the back when sitting in a car for an extended period.)
The comfort isn't too terribly compromised by the battery and converter, which are carried in a double-zippered pocket on the hip. (And yes, the largest current 20V Max battery, the 4.0 Ah DCB204 will fit, barely.) The converter is a DCB091, which is identical to the DCB090 power source that DeWalt is now selling, but with the critical addition of a 12V power jack. The power jack connects the coat's internal wiring to the DeWalt battery. (Presumably, other manufacturers' batteries could also be used, if connected to a suitable converter and 12V power jack.) The DCB204 appears to provide more than enough power for a full day's work (and such results are probably available with some or all of the smaller batteries, as well), with the coat continuing to heat itself well into the night on the 4.0 Ah battery. (UPDATE: After a few days' experimentation, it appears that the DCB204 4.0 Ah 20V Max battery will provide a bit more than seven hours of "high" heat on a fresh charge.)
As the note regarding the converters illustrates, beyond the power source in the pocket, the only thing that's really "DeWalt" about the jacket is the insignia. But unlike the excellent DeWalt tool bags and belts (which, apparently, are manufactured by Custom Leather Craft), this jacket is not especially notable for its design or its features. (There are, however, FOUR pockets - in addition to the battery double-pocket - not three pockets per the Amazon description; two large outside pockets without zippers, and two internal zippered vest pockets.) A waist cinch and zippers on the outside pockets would have been useful (but still fairly basic) additions, and a zip-off hood would have been helpful, too. But it's really about as basic as coats get, these days. Having said that, the coat could be a useful addition to the wardrobe of someone who is already using the DeWalt 12V/20V Max line (and so, has spare batteries on hand), but it's not something that should be especially tempting for anyone else.
But if you're such a person, you should note that the DeWalt sizing chart is, at best, optimistic. Judging by the experience of this reviewer (who is 6-foot 4-inch, 48-50 suit size, with a 36-inch waist, for whom the XXL size is only barely adequate), you should move up at least one size in the chart. (Of course, one could just await the corded model that will undoubtedly follow from DeWalt. It's likely to be much warmer, but probably a tad more restrictive on movement... best suited to mid-winter lounging on the deck, one supposes.)