Battery life

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Crypto000
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Battery life

I just build a Cree xhp70.2 6v, can someone advice what is the battery life if I pair it with 7.4v 6800mah 100c rating battery, or 21700 7.4v 18ah battery.

wle
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depends on the current obviously
i mean you could probably run 2A through the led, if the heat sinking is good, that might be 9 or 3.4 hours
does not really depend on the LED, other than the LED may determine the current, depending on how your driver works

wle

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ggf31416
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100C rating from a 6800mAh battery doesn’t look correct. At most 18650 can run at 10-15C, anything more probably is overrated. LPF can have 30C rating but that’s because capacity is 1/3 to 1/2 of 3.7V Li-Ion, actual discharge rating doesn’t exceed 35A.

wle
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ggf31416 wrote:
100C rating from a 6800mAh battery doesn’t look correct. At most 18650 can run at 10-15C, anything more probably is overrated. LPF can have 30C rating but that’s because capacity is 1/3 to 1/2 of 3.7V Li-Ion, actual discharge rating doesn’t exceed 35A.

a lot of the question doesn;t really make sense

wle

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Crypto000
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This is a lipo rc car battery not the 18650 li-ion.

Crypto000
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wle wrote:
depends on the current obviously
i mean you could probably run 2A through the led, if the heat sinking is good, that might be 9 or 3.4 hours
does not really depend on the LED, other than the LED may determine the current, depending on how your driver works

wle

yes will be running less then 2A most of the time so now is to consider what battery to use the rc car lipo pack 7.4 6800mAh 100c or 21700 7.4v 2s4p 18AH for the maximum runtime, so base on the calculation you stated, i will have abt 9hrs of usage if i go with the rc car lipo pack?

wle
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Crypto000 wrote:
wle wrote:
depends on the current obviously
i mean you could probably run 2A through the led, if the heat sinking is good, that might be 9 or 3.4 hours
does not really depend on the LED, other than the LED may determine the current, depending on how your driver works

wle

yes will be running less then 2A most of the time so now is to consider what battery to use the rc car lipo pack 7.4 6800mAh 100c or 21700 7.4v 2s4p 18AH for the maximum runtime, so base on the calculation you stated, i will have abt 9hrs of usage if i go with the rc car lipo pack?

for run time, get the largest mAH, simple
if running less than 2A
the 18AH (18,000 mah) is way more than 6800mAH

it seems so simple i wonder if i understand the question…
18AH/2A = 9H
that is how you do that [simple version]

wle

"You never have the wind with you - it's either against you, or you're having a good day."
    Daniel Behrman, "The Man Who Loved Bicycles".
It never gets easy, you just go faster.   
-Greg Lemond.
       ,ø¤º°`°º¤ø¸,ø¤º°`°º¤ø¸,ø¤º°`°º¤ø¸