LF HO-9 (2x3.7v beamshots)

[021411]

According to their specs you can run the HO-9 with either 2x3.7 RCR123 or 3xCR123. The lamp is rated 320 lumens.. Even though the voltages are different, would the lamp still put out 320 lumens? I know it's not the actual rating but I just want to know if the voltage difference would still put out the same amount of light..

 

[ampdude]

Re: LF HO-9 question

It will be a bit brighter with lithium ion rechargeables because their voltage sags less than lithium primaries under load, even though their initial voltage appears to be slightly less.

 

[mdocod]

Re: LF HO-9 question

depends on the cells in question. The lamp is rated to deliver 320 lumen at 7.6V at 1.55A or about 12W... however....


At that load, CR123s sag to about 2.4V, so you could expect about 7.2V minus some losses in resistance. So you could expect a steady average performance in the ballpark of 250-275 bulb lumen on CR123s for somewhere around an hour depending on brand of cells.

On small li-ion cells, like RCR123 size, you could expect them to deliver about 3.6-3.7V into that load fresh off the charger, quickly diminishing to more like 3.3-3.5V average ending around 3.1V at about the 20 minute mark, so the result is about 6.2-7.4V range minus the resistance losses. Plan on RCR123s delivering less performance and less runtime overall than 3xCR123s. The 2xRCR123 configuration will start off around 280 bulb lumen, and end around 160 bulb lumen after about 20 minutes..

If you step up to some larger format li-ion cells (like 18500s or better)... the discharge curve into that load starts off as high as 4.0V per cell, steadily diminishing to around 3.5V at the end of the discharge. so the HO-9 can deliver up to around 370 bulb lumen fresh off the charger, and diminish to around 240 bulb lumen at the end of the discharge. runtime could be anywhere from 40 to 80 minutes depending on the size of the cell.

So... As I said to start with, it depends on what cells are in question.

 

[021411]

Re: LF HO-9 question

I will be using AW RCR123's. Don't they come off the charger around 4v?

 

[mdocod]

Re: LF HO-9 question

they come off the charger at 4.2V, but when you load em with a 1.5A load, they immediately sag to about 3.7V, followed by a continuas slope down to around 3.1 before you should stop using the light...

The HO-9 paired with RCR123s, is a nice combo for short bursts, that you can recharge frequently to get the "fresh off charger" brightness, but should not be used as a continuous duty light of sorts. Technically speaking, it would be best to recharge after 10 minutes runtime, rather than draining them all the way down, because li-ion cells do not like to be sagged down that low under a load, it wear them out very fast.

In all honesty, I suggest the SR-9 or ES-9 over the HO-9 for most people when dealing with RCR123 size cells.

Notice, the SR-9 is also rated at 7.6V, but in almost all cases, since it is a lower current lamp, it will get higher voltage from the cells in question. SO while it is rated 220 lumen instead of 320 lumen at 7.6V, you get less "loss" from small cells..

So.. for comparison.. I figure the following:
HO-9 on RCR123s: ~280 diminishing to ~160 lumen in around 20 minutes
SR-9 on RCR123s: ~220 diminishing to ~140 lumen in around 30 minutes
ES-9 on RCR123s: ~170 diminishing to ~110 lumen in around 40 minutes

Now.... if you had a body that could support an 18650, you could use an EO-4, and get about 210 lumen diminishing to about 130 lumen with a runtime of about 45-50 minutes. Similar to running the SR-9 on RCR123s performance wise, but a good chunk more runtime.

 

[3mw]

Re: LF HO-9 question

Now.... if you had a body that could support an 18650, you could use an EO-4, and get about 210 lumen diminishing to about 130 lumen with a runtime of about 45-50 minutes. Similar to running the SR-9 on RCR123s performance wise, but a good chunk more runtime.[/quote]

Can AW's 17670 be used with an EO-4? How would it compare to to the SR-9 on two RCR123's?

 

[mdocod]

Re: LF HO-9 question

a 17670 will work fine, and run about 35-40 minutes or so, just slightly dimmer than an 18650. Comparing these differences is really splitting hairs, eyes can't see these differences well enough for it to matter.

Keep in mind, that eyes automatically adjust for the amount of available light, so small differences don't equate to anything useful, only massive jumps in performance are really worth aiming for if you want "the next level." A massive "jump" could be defined as at least double, more like triple.

 

[021411]

Got the lamp assembly in from Lighthound.com.. My 3.7v batteries are on the charger. I'll get beamshots up tonight.