Test/Review of USB Load resistor 1A

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HKJ
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Test/Review of USB Load resistor 1A

USB Load resistor 1A
DSC_4406
Official specifications:


  • Type: 1A discharge resistor.
  • Used For: Power bank / Battery Capacity testing.
  • Brand new and high quality.

I bought it on ebay some time ago.
The most interesting detail about this type of load is how hot they get, some power resistor has a working temperature between 200°C and 300°C when fully loaded.
DSC_4399
This type of load is very simple, two big power resistors and a led to show if there is any power supplied to it.
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Load testing


  • This type of load is only designed for 5V input.
  • Current change during 30 minutes with 1A load is 0.005A, i.e. 0.5%

USB%20Load%20resistor%201A%20voltage%20sweep
Being a resistor the current will depend on voltage.
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As expected the load current and power is stable with a resistor, except for a small drop due to temperature.
Temp3105
M1: 165,5°C, M2: 87,0°C, M3: 57,4°C, M4: 171,9°C, HS1: 181,2°C
The resistors gets fairly hot.
The correct way to mount power resistors is a bit above the board with some distance between. These resistors are only running at half their rated power, but they cannot get rid of the heat.
Temp3107
M1: 124,5°C, M2: 63,8°C, HS1: 132,1°C
Conclusion
The load works as expected and is an easy way to test usb power banks (together with a usb meter), but this model need an external fan to supply lots of cool air.
It is a bad idea to touch it when it is working.
Notes
Expect very similar performance from all resistive loads with two square white 5W 10ohm resistors.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

HKJ
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That’s it, no more resistor test in the near future!
This covers the most common 3 types:

Two white resistors 1-2A: http://budgetlightforum.com/node/46271
Two green resistors 1-2A: http://budgetlightforum.com/node/46160
Two white resistors 1A: This review.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

SawMaster
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Consistency is everything in testing and this seems to have that. Ceramics can take this kind of heat so the PC board and LED would be my concern. If they’re OK with the heat then a small ventilated box enclosure would be enough without a fan. Not sure how you’d easily mount the board in that though, there’s no ‘clean’ areas on the board for screw-in stand-offs.

Phil

HKJ
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SawMaster wrote:
Ceramics can take this kind of heat so the PC board and LED would be my concern.

FR4 laminate (The green circuit board material) can withstand about 130C continuous and considerable more for a short time.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/