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australia:heating_pads

12V heating pads / "electric blankets" to lie on

Introduction

  • there are various types of 12V “electric blanket” / “heating pads”
  • heating pads here are defined as those you place on your mattress and thus you lie on top of them
  • low output 45-50W electric blankets can generally be used as lower output heating pads or as throw rugs and most of these will have a 45 minute timer
  • car seat heated cushion pads are more robust and compact but are shorter and have longer cycling periods of 5 minutes which can result in getting a touch too warm and then too cold
  • for overnight hikers, consider small 5V USB powered pads
  • higher output heating pads eg 75W must not be allowed to overheat as there may be a fire risk!
    • in general, they must be fixated to the mattress to avoid scrunching or doubling up
    • they should not have insulating materials such as a sleeping bag placed directly on top - use a quilt or blanket over your body instead of a sleeping bag (or open the sleeping bag as a quilt)

high output electric blanket style heating pads

  • ElectroWarmth T36 mattress pad
    • $AU122 Made in USA - may be available on Amazon.com.au
    • 75W 7 power settings, “3.1A” on lowest setting, 6.5A on highest setting.
    • no auto-off (can get separate controller)
    • MUST NOT be allowed to scrunch up or be folded whilst on as risk of fire!
      • hence requirement to:
        • secure to mattress such as via safety pins to attach to mattress etc
        • not use with insulating material such as sleeping bag on top of mattress
        • ensure it is turned off when not in use
    • can be hand washed as long as controller does not get wet - risk of shrinkage!
    • they advise to cover with thick quilt to protect it from sweat and dirt - not sure how this differs to a sleeping bag that has been crushed by the weight of your body!
    • auto off seems to occur at around 11 hour mark
    • heat settings and power usage:
      • Setting 1: seems to run at <3A when ON but has long OFF periods so gives minimal heat
      • Settings 2-7 run at 6.5A when on but the proportion of time it is on increases as setting increases until constantly on at level 7 when it hits surface temp of 48degC but will drain your battery quickly - great to get warm quick in 15 minutes but then turn it back to setting 3 or so!
        • Setting 2 On 1 sec Off 1 sec so average is around 3.1A?
        • Setting 6 On 2 secs Off 0.5sec
    • not as power efficient as a car seat heater pad as it is much wider than your body and the heat is more spread out but it does provide continuous heat instead of the annoying 5 min off cycles

lower output "electric blankets"/ throw rugs

  • Kickass blanket 3 settings
    • $AU69 1.9A, 2.85A, 3.8A (46W) with 45min auto off
  • many others online - some with only 1 heat setting, some with 2-3 heat settings.

car seat heater pads

  • shorter and stiffer than electric blankets (need two for upper body and legs)
  • most have peak output at around 48W but average 1-2A power usage as they cycle on and off in 5 minute cycles
  • usually have two heat settings
  • will raise 2P fabric enclosed tent temperature by around 2-4degC as well as providing direct heat
  • there are plenty on Ebay
australia/heating_pads.txt · Last modified: 2022/04/30 11:27 by gary1