maths problem for someone

[aljsk8]

7mce leds direct drive off 12v 24ah sla

mce are 5a bin neutral white at 370min lumens at 350ma

following measurements taken at the battery terminals with the light on:
12.4v
3a

please could someone tell me approx lumens (give or take 100lumens) from the above info - i think i have the answer but need sanity check
the whole unit is cooled to room temp

 

[spencer]

If I had time to look it up I would but really quickly I would say somewhere around 3000-2750.

 

[znomit]

If I had time to look it up I would but really quickly I would say somewhere around 3000-2750.

+1
... but only at the moment you measured the output. Direct drive is like that.

 

[AnAppleSnail]

7mce leds direct drive off 12v 24ah sla

mce are 5a bin neutral white at 370min lumens at 350ma

following measurements taken at the battery terminals with the light on:
12.4v
3a

please could someone tell me approx lumens (give or take 100lumens) from the above info - i think i have the answer but need sanity check
the whole unit is cooled to room temp

MC-E datasheet

Gonna assume these are 4s MC-Es. Each MC-E sees 1/7th of 3 amps, or 0.43A. It's a K-bin MC-E, so you're starting from 370 [email protected]. The extra current gives you 120% of that output, so 444 lumens per MC-E.

444*7 = 3100 lumens. This figure is approximate and assumes that all Vf is the same - it's not, so actual is lower for that and other reasons.

If the LED is 50C warmer you get 10% decreased output. As battery voltage drops, current will also drop.