Answered: Quark Runtime/Battery Question

THE BELOW INFO IS INACCURATE, SINCE I DID NOT TAKE INTO CONSIDERATION THE OUTPUT Vf VOLTAGES, AND ONLY LOOKED AT mAh.
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On the Quark AA^2, at max of 700ma, the runtime is only 1.3 hours, suggesting a power usage of 0.91mAh (1.3hr*.7A). What happened to the rest of the battery's capacity?!

Spreadsheet, formatted as: Mode, mA (to LED), hours, capacity (mAh)
If the driver had high efficiency, then the Quark AA(^2) should have close to 2.00mAh, but the surprisingly low values suggest 63% efficiency (AA^2 on med) and 21% efficiency (AA on max). Even the Quark 123 which has similar voltages to the Vf has similar results.


For your reference:
Quark AA^2: http://www.4sevens.com/product_info.php?cPath=297&products_id=1620
Quark AA: http://www.4sevens.com/product_info.php?cPath=297_305&products_id=1597

Re: Quark Runtime/Battery Question

ImGeo said:

On the Quark AA^2, at max of 700ma, the runtime is only 1.3 hours, suggesting a power usage of 0.91mAh (1.3hr*.7A). What happened to the rest of the battery's capacity?!

Click to expand...

There are two factors you must include:
1) The driver is changing the current, i.e. led and battery current are not the same.
2) When discharging a battery at high current it has lower voltage and lower capacity (mAh).

Re: Quark Runtime/Battery Question

HKJ said:

There are two factors you must include:
1) The driver is changing the current, i.e. led and battery current are not the same.
2) When discharging a battery at high current it has lower voltage and lower capacity (mAh).

Click to expand...

1. Agree and I understand, but the efficiencies seem surprisingly low, or is such efficiency ~50% common, even for high quality lights?
2. But what about the medium modes at a fair 250mA (and probably 500mA from battery)

Re: Quark Runtime/Battery Question

ImGeo said:

1. Agree and I understand, but the efficiencies seem surprisingly low, or is such efficiency ~50% common, even for high quality lights?
2. But what about the medium modes at a fair 250mA (and probably 500mA from battery)

Click to expand...

Efficiency can be rather low at low voltages, but try doing you calculations with power instead of just using mAh and the measured runtimes (See selfbuilds review).
You can also find some better battery capacity figures in our battery section.

Re: Quark Runtime/Battery Question

HKJ said:

Efficiency can be rather low at low voltages, but try doing you calculations with power instead of just using mAh and the measured runtimes (See selfbuilds review).
You can also find some better battery capacity figures in our battery section.

Click to expand...

THANK YOU!!!! I felt something was unreasonably wrong, but then I realized that I did not take into consideration the output Vf of 3.3-3.7v (and rather treated them at the battery's voltage!

The outputs now seem to make a lot more sense :twothumbs