For the last month, I have been testing the GHJ12V Bosch Heated Jacket. Like the Milwaukee heated jacket or the Milwaukee heated hoodie, the Bosch GHJ12V heated jackets include three electric blanket-like patches. You get one in the lower back and two in the upper chest. The former model had the rear heating zones up top, but they tended to draw in colder air from below. Bosch moved them after listening to user feedback.
They generate heat when connected to the 12V 2.0Ah battery residing in an inside pocket. Like Sam McGee in Robert W. Service’s poem, there are people who are always cold, and I think this jacket is aimed at them. They can never get warm enough and are the happiest soaking up the sun like a cat in the savanna. I, on the other hand, like the shady side of an iceberg and avoid heat whenever possible. One of my favorite forms of recreation is skiing, be it X-country or downhill.
See our heated jacket shootout for an ever wider perspective.
Bosch Heated Jacket Features
In another life, I have spent up to three weeks at a time outside in arctic conditions. It hovers around 0° F in and around Fulda, Germany in January. I can tell you that there is nothing colder than the inside of an armored vehicle with a busted heater because of a shortage of igniters in the Army supply system. Proper clothing is crucial to survival in winter weather and we all looked like Michelin Men in Army issue. The biggest problem with this bulky clothing was that it was about 2” thicker than certain anatomical parts…Relieving oneself was problematic.
Like home insulation, modern clothing has dramatically evolved. Good-looking clothes that are really warm but not bulky are readily available today. However, a big factor in staying warm outside is wind chill. The effective temperature is lowered by about 1° F for every mile per hour of wind. For this reason, motorcyclists and snowmobilers have for some time appreciated electrically heated clothing that laughs at wind chill. While the 720-watt alternator on my BMW GS can toast bread as well, it’s not so hot at heating up clothes. My wife, who hates being cold, loves her heated jacket, but I do not own one.
Can a 12V Battery Power a Heated Jacket?
With the above in mind, it was with some skepticism I started looking at the diminutive battery of the Bosch GHJ12V Heated Jacket. In a perfect world, the 12V 2Ah battery—the same battery that powers the Bosch 12V brushless compact drill/drivers—produces 24 watts. It takes .2931 watts to generate a BTU, so our battery will produce just 82 BTUs or a little less than 21 kilocalories, which is the way we measure food intake. One slice of white bread generates 84 calories in your body.
That’s not a lot of heat. However, as anyone who has used a chemical hand warmer knows, a little heat can make all the difference in preventing frostbitten fingers or toes. It is easy to heat a broom closet but very difficult to heat a barn. I have worn the jack most every day in a wide variety of temperatures, ranging from the high 40s to the low 20s.
The puny battery for the GHJ12V Bosch heated jacket really makes you scratch your head when you pull it from the box. It fits into a plastic housing that Bosch calls a holster/controller. A terminal connects it to the coat, and you get a USB connection for charging your phone. It will run a cell phone for a good long time! Before I give my findings let’s take a closer look at the jacket.
Bosch Heated Jacket Features
Designed in Denmark, the black Bosch heated jacket is stylish and close-fitting with adjustable cuffs and waist. The cuffs adjust with Velcro tabs, and the waist has a drawstring. There are generous zippered handwarmer pockets on each side. Next, you get a large inside mesh pocket for gloves at the right waist level. Finally, a zipped battery pocket sits at the left waist level. There is also an outside zipped cell phone pocket at the left chest level. Buttonholes in the battery and cell phone pockets let a USB charging cable run to a USB port in the battery holster.
The Bosch GHJ12V heated jacket is manufactured in Vietnam. Material and tailoring are excellent—worthy of Saville Row. The insulation is very good, and the outer shell is extremely windproof. The insulation and the wind-blocking shell are the keys to this jacket’s performance.
The European design is further evident in the left-handed zipper, which is common on the continent but not in America. This does not annoy me, but others may wonder if they got a manufacturing snafu (you didn’t). What does annoy me is that the zipper is small and hard to zip with gloved hands. What’s more, is that the bottom jumped out of its starting ramp and came undone a number of times during my testing. Once was just coming off a ladder onto a snow-covered roof. You can lose a lot of heat getting a derailed zipper re-railed, especially when gloves must be removed. The zipper is not what climbers call “bombproof”.
The battery and holster shapes are also unfortunate. It’s like having a baseball in the handwarmer pocket of a normal coat. It is not a deal-breaker, but a bit cumbersome. I would like to see a much more robust flat battery pack or, better still, two such packs in series left and right. The form may need to trump function in this case.
Bosch Heated Jacket Controls
The Bosch GHJ12V has a square button just below the left collar. To bring up the heat you push it for several seconds. It starts on high and glows red but another stab turns things down to medium and it glows green. A third push brings heat to low (a blue color), and it will run about 6 hours on this setting—something I have confirmed to be true in my testing.
The placement of the button was for fashion and possibly not for function, for you can’t see it unless you unzip halfway. That wastes a lot of heat. What is more, you cannot see the colors outside, even in the subdued light of a blinding snowstorm. You have to push, hold, and count to ten, then push once or twice more depending on the setting you want. That it started successfully has to be taken on blind faith, or you have to go inside into very subdued light to confirm the heat setting—or whether it is even on. Outside you will only know if you stick a bare hand inside under one of the chest heat zones. It would be easy to become the Napoleon of the job site, especially if you’re autocratic to start with.
Bosch GHJ12V-20 vs GHJ12V-10
The Bosch GHJ12V-20 represents a design change from the GHJ12V-10 heated jackets. You get an additional pocket and the new jackets specifically mention “machine washable” in the description. As we mentioned, the rear heated zone moves down to the lower back.
|Front Heating Zones||2 Chest||2 Chest|
|Rear Heating Zones||2 Lower Back||2 Upper Back|
|Battery Adapter||12V w/USB Port||12V w/USB Port|
|Outer Shell||100% polyester||100% polyester|
|Price (S-XXL kit)||$199||$199|
Bosch GHJ12V Runtime
On High, the Bosch heated jacket will really make a difference in warming you up, but it will not run a long time on this setting. The high heat setting of this coat is much the same as popping a chemical hand warmer, and as mentioned above that can be a lifesaver. If you go through a lot of chemical hand warmers, and they go for a little less than a buck a throw, there may be value here. Low makes some heat, but on a cold day, I cannot even tell if it is on if I am wearing a heavy shirt/undershirt.
The windproof fabric is also water repellant, but the directions, which I rate at 4 out of 10, strictly forbid using it wet, and for good reason. I stood in light rain for a couple of hours with nothing getting through the shell. When wet, however, the fabric attracts sawdust, mortar, brick dust, and dirt like a magnet. Directions strictly forbid machine-washing, so you are stuck with hand-washing which is a hassle. I wash my Carhartt jacket about every two weeks.
You can pick up the GHJ12V Heated Jacket for $199, with the 3X version running $10 more.
- Nice looking
- Not bulky
- Comfortable riding in a vehicle
- Zippered cell phone pocket and charging capabilities
- Left-hand zipper
- On/Off button problematic
- Battery shape is like a baseball in pocket
- Attracts dirt readily
- Can only be hand washed
- Need three batteries for a whole day use
Editor’s Note: We initially did this review on the Bosch PSJ120, however, Bosch has made very few changes to the original design with the exception of moving the rear heating zones down and making minor improvements to efficiency and runtime.