The Guide of Battery Heated Clothing for Buying
What to look for when buying an electric heating suit. How hot does it get? How long does it heat up? These are not the real questions you want to answer. What you really want to know is. Will it keep me warm when I need it? You need to consider a number of factors.
Garments with good wind insulation will trap heat better, which means the heat generated will cocoon in your core, keeping you warm longer. This means you can lower the heat setting on your controller and still stay warm. As a result, the battery will last much longer than if you left it on constantly. So better insulation acts like a battery extender - increasing the amount of time you stay warm.
You also need to consider "dynamic" insulation. In the cold world outside, the wind will suck heat away from your body, and if the garment fabric is not windproof, it will negate any benefit of fabric insulation. An example of this is if you're ever outside in a polar fleece and a breeze blows, the wind goes right through as if you're not wearing anything. Look for higher performance, multi-layer windproof insulating fabrics.
Heat levels and controls
If your suit has the right insulation, you may not need to turn the heating level up all the time, so to extend the heating time of your battery, choose a model with at least two heating levels, high and low. More than three heating levels can become confusing, so don't choose a model with a complex control system.
Basically, if the controller has more than one button, it becomes too complicated to use when you're outside in an environment where you want to simply adjust the heat. For the sake of convenience, you don't want to be looking around inside your suit for a battery pack just to adjust the heat level, so look for a model with a separate heat level controller and battery pack.
What you don't know can hurt you, and this is one of the most important issues, many electric heat garments come with their own custom rechargeable batteries. Now, you won't want to consider anything other than a high energy density, cold weather performance and lightweight lithium rechargeable battery type.
To protect the soft battery cells, the battery pack should have at least a rigid polymer/plastic case. In addition, some models add additional protection, such as a neoprene case, to further protect the battery cell from impact damage.
If you are going to be in the woods for a few days and not near a rechargeable power source, you need to consider whether the model has the option of using regular size high drain AA batteries, which will also come in handy if you accidentally run out of battery juice and need to pick up some AA batteries from a nearby store to get you through a few more cold hours.
Risk of electrocution. A common concern about heated clothing seems to be a misconception about electrocution, especially when it's raining. Portable electric heated clothing is virtually impossible to electrocute. Since most rechargeable heated clothing systems, such as electric undershirts and jackets, operate at low voltages below 10V, you can jump into a river and at worst you will feel a slight buzz. Most battery heated jackets run on as little as 7.4 volts, which is less than the voltage of many children's electronic toys.
High-frequency electromagnetic field radiation. All battery-powered electric heating suits are safe for high-frequency EMFs, as well. Any battery-powered electric heated suit operates at less than 13V DC at 0 Hz, so there are no EMFs.
The problem with workmanship. As with any product, all electric thermal suits are not created equal and poor wiring design and workmanship can lead to "hot spots" which do pose a safety risk. You need to be confident that the product you are buying is safe. So, how can you build that confidence? First, check to see if the manufacturer has independent testing to verify safety.
Watch out for marketing hype. For example, when a product is marketed as having up to 10 hours of heat, it may mean 10 hours at a 10% heat setting, which is almost no heat. When they give a temperature rating, it may be at the highest setting that only works for the shortest amount of time.
Don't make the mistake of seeing a high temperature rating and assuming it lasts the same amount of time as the lowest heat setting. Another trick sometimes employed is to heat the garment in only one area (less heated), which means the manufacturer can claim a longer heating time.