Questions Re: Malkoff HCRI on AA's--POLL ADDED Re: More Makoff HCRI's

I want to build a High CRI flashlight that can run on Eneloop NiMH AA's, but I need some advice and a nudge or two in the right direction.

I know that the operating voltage for the Malkoff M61 HCRI is 3.4V-9V, which means that at the minimum I'd need to use three Eneloop AA's (to get above 3.4V), and a maximum of seven Eneloop AA's (which yields 8.4V).

So here's my first noob question: is there any benefit in terms of brightness to going above the stated minimum of 3.4V? Or does regulation imply that the electronics will only allow for a certain brightness (in this case approx. 150 lumens) regardless of how many Eneloop AA's I use to power this thing.

Lastly, what hosts (if any) would allow for this setup?

Thanks fellas!



EDIT: POLL ADDED AT THE TOP OF THIS PAGE:

Poll Question: Would you purchase a Malkoff M31HCRI, a M31HCRIL, Or a M31HCRILL?

Re: Questions Re: Running Malkoff M61 HCRI on AA's

Regulation should keep output flat above the 3.4v minimum, though I'm not completely familiar with the regulation of the M61. Remember the regulation would drop out once each cell was below 1.13v if you only used 3 cells so you wouldn't get full power for the whole capacity of the cells, maybe that is a good thing however as it will give a nice warning of when capacity is low.

Unfortunately I can't think of any 3x AA P60 hosts, which is a shame as it seems a good niche in the market. There are a few 3x AAA ones such as the solarforce L2i but I would think it would be easiest to either use an M31 HCRI (if they are made) and a two cell host, or swap a high CRI XP-G into a production AA light, they only cost about $7 from illumination supply. I swapped one into my old D10 GDP along with a D11.2 circuit and it worked out very nicely. I'd love to do a transplant on a BA20 though..

Re: Questions Re: Running Malkoff M61 HCRI on AA's

I just tried an M61 HCRI head on an MD3 with 2 eneloops, about 2.6 volts open circuit ...It is about 25 lumens on high (just below med1 on an H51Fc), and moon mode (1 lumen?) on low.
On a Fivemega 3xAA with 3 eneloops at 3.8 volts open circuit, it looks like it's slightly less bright than another HCRI in an MD2 with an 18650 at 4V. Not a huge difference, but noticeable. 100 lumens? versus 150.

With the older M60 line, for max brightness it was best to use 6-9 volts (2 or 3 CR123, or two Li-ion rechargeables). When the battery voltage is at the regulation borderline, high current draw will cause the battery voltage to sag due to internal resistance in the batteries. Higher battery voltages will result in less current drawn by the driver, which the batteries can deliver more easily, so there's less voltage sag under load.

So, if you want to get the full output from your M61, 3 eneloops in series should be your minimum. 4 would be better, except that you won't get a dimmer light before the NiMH batteries reach the 1.1 volt "empty" point.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

LightHound has the Leef 3X18650 C-C host on clearance. Add a SolarForce tail and head and make a sleeve to hold the AAs. Not exactly cheap but very rugged.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

Thanks for all of the suggestions and insight.

So, do you guys think it might be wiser (and more economical) to just pick my favorite flashlight and have it modded with a High CRI emitter?

If that seems like the better and more sensible way to approach this, then could you guys recommend me some people who do this sort of modding? (feel free to send via PM)

Re: Questions Re: Running Malkoff M61 HCRI on AA's

Just a suggestion, but have you looked into a M31W? It has the lower voltage that your looking for. Pretty close to the HCRI setup that you are describing (3700K tint) with the lower voltage.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

I have an M31W I bought on the Marketplace in a Solarforce 2AA host, and it runs great on two eneloops.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

Thanks for the suggestions on the M31W.

I really do have my heart set on High CRI, so I'm still going to pursue that and see if it's possible. I guess that a M31HCRI or an M31HCRIL would be ideal for this, but alas those do not exist.

I did contact Gene and he told me to give him a call on Monday to discuss options (once he's returned from SHOT), so I'm curious to see what he'll say.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

I would really, really love an M31HCRIL as well, but until then I gotta say that the M31WL is very nice, without having an incandescent to compare it to I can imagine mistaking it for one.
I've been running it as an old style "flash" light with a single AA Eneloop and I think I'm getting close to an hour of intermittent use out of it before it's noticeably dimmer.

"When the battery voltage is at the regulation borderline, high current draw will cause the battery voltage to sag due to internal resistance in the batteries. Higher battery voltages will result in less current drawn by the driver, which the batteries can deliver more easily, so there's less voltage sag under load." -Max Power

I'm sure I'd have a much happier battery with 2 AA Eneloops powering it, but I have set two Eneloops aside for hard living and they are each holding up fine so far, I run them down to about .9v working singly with either the M31WL or Zebralight H51Fc. -both batteries are performing like champs with either one, again with a single AA for each.

Was about 2 amp draw on single Eneloop with M31WL.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

eh4 said:

I would really, really love an M31HCRIL as well, but until then I gotta say that the M31WL is very nice, without having an incandescent to compare it to I can imagine mistaking it for one.

Click to expand...

Normally I'd just go with the M31WL, but my intention for this light is to gift it to someone who does a lot of night hiking, so the added lumens and the High CRI aspect would be utilized quite often.

That said, it's encouraging to know that the M31WL's beam is so close to that of an incan.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

RedForest UK said:

Unfortunately I can't think of any 3x AA P60 hosts, which is a shame as it seems a good niche in the market.

Click to expand...

2AA and 3AA D26 (P60) hosts are available here.
Remember if you use 7 Eneloops, the time total voltage drops and reaches to 3.4 volt, each cells has less that 0.5 volt which is already too late to notice and recharge.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

Well if you convince Malkoff HCRI do be sure and let us all know. ;-)

Nice looking bodies fivemega.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

eh4 said:

Well if you convince Malkoff HCRI do be sure and let us all know. ;-)

Click to expand...

I wonder if he's had a lot of requests for a potential M31HCRI or M31HCRIL. If he came out with either one I'd buy it, throw it in his Little Twisty 2xAA, and call it a day. :thumbsup:

I should note that I did also consider one of 4Sevens' limited run Preon 2 HCRI, but I really want the longer runtimes that 2xAA+ would provide.

brandocommando in the "Show your High CRI Lights" showed a L2r with a M31HCRI, so they do indeed exist...

Re: Questions Re: Running Malkoff M61 HCRI on AA's

I remember agonizing over whether to buy an M31HCRI and at the time told myself I'd probably put the wrong batteries on it and burn it up. Now I'm not so sure, if I have the MD3 with the home-made AA sleeve I won't be able to physically fit a fat cell in there. So I just have to be extra careful when trying other bezels on the 2xAA body, that I don't put the M31 on another body.

Re: Questions Re: Running Malkoff M61 HCRI on AA's

Just a little HCREYEcandy...



I am always very careful to remember what host this is in. (And I always keep it it a 2AA or 2C host.)

I love mine, and I can tell no difference in brightness between this and my M61HCRI side by side.