Friday, November 10, 2017

Bright Lights- revisited!

5000 Lumen 2x CREE XML U2 LED Cycling Bicycle Bike Light Lamp HeadLight Headlamp

I had purchased the 5000 Lumen 2x Cree XML U2 LED bike light via Amazon this week for $22.  I used it last night for the first time.  My impression?  Fair at best.  You get what you pay for.  The light has 3 brightness settings: High, Med & Low.  It puts out a good flood light with a width of about 30-40 ft.  The length of light (ahead of the bike) is about 20 yds.  It definitely doesn't put out 5000 lumens.  I'm not even sure it puts out 2000 lumens.   If I had to guess, I'd say it's more like 500 they had a typo in their advertised output. 

I fully charged the battery pack (4 x 18650 Lithium-ion batteries) before I connected it to the light.  I have no idea what the capacity of the 4 batteries are.  There was no paperwork.  If I had to guess, I'd say each battery had only an 1100 mAh capacity.  And, I'd say two of the batteries were connected in series and two in parallel from looking at the case.  Since Li-ion batteries have a terminal voltage of 3.7v that makes for a 7.4v on-load voltage for the battery pack (2 batteries in series).  The charging voltage of the battery pack is 8.4v and is advertised as such.  Therefore, the battery pack is an 8.4v 2200 mAh battery pack.  Why do I think the capacity was only 2200mAh?  Because 3/4 of the way through my 1.5 hr. bike ride, the light shut down completely.  It just shut off.  And, that was on Med power.  I knew there was no way the battery pack would last the entire 1.5 hr. bike ride on high power. 

Anyway, I'm in search for a new battery pack for my new light.  I'll probably end up paying more for the battery and charger then I did for the entire kit...but that's ok.  I knew a 5000 lumen bike light for $22 was unrealistic.  When I get a new battery hooked-up, I'll give yet another report/update.

Until then, Power ON!  Coach Rob

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