What to
look for when buying heated clothing. How hot does it get? How long will it heat for? These are
not the real questions you want answered. What you really want to know is: Will it keep me warm for as long as I need?
You need to consider a number of factors:
Insulation
Garments with good, windproof insulation will trap the
heat better meaning the heat generated will cocoon around your core, keeping
you warm longer. This means you can lower the heat setting on the controls
while still staying warm. As a result, the battery will last much longer than
if you left it on continuously. So the better insulation is like a battery
extender – increasing your warmth time. You also need to consider “dynamic”
insulation. In the cold world outside, wind can suck the heat from your body,
negating the benefit of any fabric insulation if the garment fabric is not
windproof. One example is if you have ever been outside wearing a polar fleece
jacket, a brisk breeze picks up and the wind just cuts right through as if you
have nothing on. Look for higher performance multi-layer windproof insulating
fabrics.
Heating Levels and
Controllers
If your garment has the right insulation, you probably
won’t need to have the heat level on the highest setting all the time so to
extend your battery heating time, choose a model that has at least a high and
low heat setting. More than three heat levels will become confusing so don’t
pick a model with a complicated control system. Basically, if the controller
has more than one button, it’s going to get too complex to use when you are out
in the elements and want to simply adjust the heat.
For convenience, you’re are not going to want to dig
around down inside your garment for the battery pack just to adjust the heat levels so look for a model
that has a separate heat level controller and battery pack.
Batteries - What you don’t know CAN hurt you! This is one of the most important, but
often overlooked aspect of buying any rechargeable heated garment. Getting this
issue wrong can be a real problem.
Rechargeable Lithium Technology.Many
heated garments are supplied with their own custom rechargeable battery.
Nowdays you wouldn’t want to consider anything other than lithium rechargeable battery type for high energy density, cold weather performance and
light weight.
Impact Protection – Oops, I dropped it! To protect the
soft battery cells, the battery pack as a minimum should have a
rigid polymer/plastic casing. Further, some models have increased added protection
such as neoprene outer cases to further to protects the battery cells against impact damage (when you
take it out and accidentally drop it – it will
happen!).
AA Battery backup
option. If you are
going out in the woods for a few days and are not near a charging power supply,
check to see if the model you are considering has a choice to use regular size high-drain AA
batteries (such as Energizer Lithium AAs). This can also be handy also if you unexpectedly run out of battery juice
(such as you forgot the recharge the battery!) and need to grab some AA
batteries from a nearby store to get you through a few more cold hours.
Other safety issues:
What about electrocution risk? A common concern about heated clothing seems
to be a misconception about electrocution, particularly when it rains. It's
virtually impossible to be electrocuted by portable heated clothing.
Since most rechargeable heated clothing systems such as heated vests and heated
jackets run on low voltages less than 10V, you could jump into a river and the
worst that could happen is you'd feel a mild buzz. Most battery heated clothing
runs at voltage of only 7.4Volts which is lower than used in many children
electronic toys.
What about that High Frequency EMF
radiation? All battery
powered electric heated clothing is also safe from high frequency EMF. The
voltage operating any battery operated heated clothing is less than 13V DC, and
the frequency is 0 Hz so there is no EMF.
Poor workmanship is another story. In 2007 at least one maker
of battery heated clothing had their products recalled by a national retailer due to the risk of it overheating
or catching fire. As with any product, all heated clothing is not created
equal. Bad wiring design and workmanship can cause “hot spots” which do have a
safety risk. You need to be confident the product you are buying is a safe
one. So how can you develop this confidence? Firstly, check the
manufacturer has independent tests to verify safety.
Watch out for marketing
hype. For example, when
a product is marketed as having up to 10 hours of heat, it probably means 10
hours at a 10% heat setting which is hardly any heat at all. When they give a
temperature rating ,it’s probably at the highest setting which will only work
for the shortest time. Don’t make the mistake of seeing the high temperature
level and thinking it’s going to last for the same time as the lowest heat
level setting. Another trick sometimes employed are with garments that only
heat in one area (less heating) which means the manufacturer can claim a longer
heating time.
