Lumapower D-mini VX Ultra (SST-50) - which battery?

Hello,

I just got my flashlighyt today, but I'm still puzzled about battery choice...:thinking: What battery would you recommend for the shorter version (without extender) and what for the longer one (18650). I know the type of battery needed, of course, but I would like to have best one possible, which means, could you recommend, please, specific capacity, specific manufacturer and specific charger for the battery? I know I'm maybe a bit lazy of searching, but I'm getting sick :green: when I think, how much time have I spent of flashlight searching recently and for the last few weeks, and now when l think I would need to do the same for the battery... Pls, forgive me that... I just want to squeeze that flashlight to a maximum using that 2 different type of batteries without destroying them too quickly, if you know what I mean...
I will REALLY appreciate your answers.
And one more thing - as for batteries I'm complete rookie here, I just simply know nothing :eeew:

Almost everyone will say AW for the batteries. The most reliable brand in CPF for rechargeable li-ions.

I wouldn't even run that light on any RCR123 unless your experienced with batteries and what can happen. So do your self a big favor and use the 18650 in that light. You might get a little more then you bargained for trying to run Cr123 or RCR123 in the SST-50.

You should be fine with an AW IMR16340 it's rcr123 sized but safer for this light. AW has a thread in marketplace selling them also lighthound carry them on their site. While you're at it, you should get an AW 18650 for longer run time.

I just want to emphasize the IMR part of spellitout's suggestion. The current pulled from an RCR123 (non-IMR) is over 2A, which is way too much draw for standard Li-Ion chemistry, at least for RCR123. It's pretty easy to tell the battery isn't happy even without a DMM, because it starts heating up like crazy as soon as you use max. When it comes to Li-Ion cells, heat == bad, and extreme heat ==

IMR cells, though, are designed for much higher currents. An IMR 16340 (RCR123) is ok up to 4A.

18650s will be fine regardless of what type you pick, by virtue of just being bigger (even a standard 18650 is ok to above 4A).

Just to warn you, though: IMR cells are not protected, so you should never run them below 2.5V (they won't cut themselves off like protected cells). Also, to make life more difficult, IMR cells have much less capacity than regular Li-Ion cells of the same size, so your runtime will be less. On the other hand, they deal with high currents so much better than regular cells, that a "higher capacity" regular cell won't actually last that much longer under high draw.

There are some runtime charts for the various battery types here:
http://candlepowerforums.com/vb/showthread.php?t=256647

Edit: I just looked at the charts, and they really show the effect of high currents on batteries not designed for them. Note:
RCR123 (750mAh capacity): 11 minutes
IMR RCR123 (550mAh capacity): 13 minutes

well said grunscga :thumbsup:

Thank you for your replies, guys - much appreciated!
Ok then, so I'm safe to use 18650 battery in this light and it will be like "normal usage", without worrying too much, that flashlight will explode in my hand :laughing:.

As for IMR 16340s. Assuming that I'll be using them only for short blasts (like 2-3 seconds, however on full power) is there still gonna be a problem with them? You know, I'm not considering this flashlight as my primary EDC light. It will be something different for me. Firstly - full power from time to time just to briefly look around my backyard and secondly I really do need smallest size possible. I will be using 18650 as well, that's for sure, but if that flight has smaller tube for smaller battery, why not to use it? I just wanna doit safe...

Finally, could you recommend some chargers for that two types of battery? Thanks again for all your help!

IMR16340 are safe for that light, even for longer periods of time, just pay attention that you don't drain the cell under 2,5V.

If you mean RCR123 for short bursts, that should be OK, but you know how it is, first you pay attention, than suddenly the light runs hot while you think that you turned it down on low, so, do yourself a favor and let RCR123 out! The risk of venting and explosion should not be underestimated, those risks are real and dangerous.

I'm waiting for my SST50 to arrive and I'll use it with an 18650 only, as I'm waiting for an EDC-SST50 from Mac, which runs on IMR16340. Mac wrote it bold and red in his sales thread : IMR cells required and intermittend use only. I wonder if the Lumapower is safe to run constantly on high unattended, I would not advise to try. Hold it in your hand and you'll feel when the emitter begins to sweat...

This special light is probably fun if you know how to use it, but could turn into a nightmare if somebody mistakes it for an EDC. :wave:

If you're only going to run it for 2-3 seconds at a time, you could use regular RCRs. The IMR is rated for continuous use at currents well above what the VX Ultra draws. Assuming that you don't let the light itself overheat, you should be good to go for the entire 13 minute runtime.

The IMR cells actually aren't too far off vanilla cells in terms of capacity. AW rates his cells a bit more conservatively than some of the other stuff out there.

This light on RCR IMR cells works great. Expect about 13 minutes battery life on high. It's a compromise, but hey - you carry a backup anyway, right?

I've been running mine on IMR18650, and tried it on some TrustFire protected 18650s for a while and a IMR16340 once. All worked fine and provided the same brightness. I should mention mine is the D-mini EX with SST-50. I'm just --guessing-- it's the same driver etc?

oronocova said:

I've been running mine on IMR18650, and tried it on some TrustFire protected 18650s for a while and a IMR16340 once. All worked fine and provided the same brightness. I should mention mine is the D-mini EX with SST-50. I'm just --guessing-- it's the same driver etc?

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If you have a D-mini with an SST-50, it's the "D-Mini VX Ultra". This is the only one that requires IMR cells, since it pulls ~2.1 amps on high.

Henk_Lu said:

IMR16340 are safe for that light, even for longer periods of time, just pay attention that you don't drain the cell under 2,5V.

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Thanks, Yeah, but how will I know that it went under 2.5V already while I'm somewhere outdoor, in the dark and far away from home? :huh2:

kdaq said:

This light on RCR IMR cells works great. Expect about 13 minutes battery life on high. It's a compromise, but hey - you carry a backup anyway, right?

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Of course . At the moment is Fenix TK11, but I'm looking forward to get Jetbeam RRT-0 soon
One more thing - I just received my 18650 batteries. I got two of them, but I'm gonna use only one. The second one is the spare one. So the question is - should I use those two alternatively or use only one of them and leave the other one untouched to be eventual replacement in the future?
Anyway - if I get some free time, please look forward for beamshots and comparison with TK11. It should happen next week, anyway
Cheers!

You shouldn't let it get anywhere near 2.5V. For example, AW considers his batteries "empty" at 3.5V. Unfortunately, without a voltmeter you can't tell exactly what the voltage is, but if you look at the runtime charts in the review I linked above, the output of the light starts dropping quite rapidly, which should be noticeable. I believe selfbuilt mentioned that the battery was still at 2.7V even when he let the light run down to only 10% output. You shouldn't let it go that low on a regular basis, but then again, you should be able to tell the battery is giving out before the light hits 10%, too.

The key is to never, ever try to charge a battery that is below 2.5V. Since the odds of having a voltmeter when you're charging the battery are pretty good (even a cheap $9 one will work), it's not usually a problem.

Personally, I would alternate batteries, because that will keep them both "even". Like any rechargeable, they slowly lose charge over time, and should be stored at or over 3.8V. This means that even if you're not using one, you'll still have to charge it from time to time, which basically "wastes" charging cycles that you could have otherwise gotten some use out of.

Przemo(c) said:

Thanks, Yeah, but how will I know that it went under 2.5V already while I'm somewhere outdoor, in the dark and far away from home? :huh2:

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It is not really a problem, the light looses a lot of brightness when the battery gets below 3 volt.

The reason the IMR cells are not protected is the chemistry is different. THey don't really have the too low voltage and you can ruin the cells problem. You should notice the light level drop- then stop. IMR cells have a smaller capacity, but are able to use most of it, so are a good choice.

Does the D-mini run hotter/faster with an IMR18650 due to it's lower resistance and ability run drain amps faster?

kdaq said:

If you have a D-mini with an SST-50, it's the "D-Mini VX Ultra". This is the only one that requires IMR cells, since it pulls ~2.1 amps on high.

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Nah I was lucky enough to win the EX with SST-50 in the Christmas giveaway they did. Not sure if it would be the same circuit as the production VX Ultra or not... Mine is H > M > L, starts on H always, ie no memory. I use IMR18650s and they work great!... but it ran ok on the trustfires... I just didn't trust them in the light. You just have to watch the voltage on the IMR cells closer since they are not protected. That goes for any light and any li-ion really though I suppose.

oronocova said:

Nah I was lucky enough to win the EX with SST-50 in the Christmas giveaway they did. Not sure if it would be the same circuit as the production VX Ultra or not... Mine is H > M > L, starts on H always, ie no memory. I use IMR18650s and they work great!... but it ran ok on the trustfires... I just didn't trust them in the light. You just have to watch the voltage on the IMR cells closer since they are not protected. That goes for any light and any li-ion really though I suppose.

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I have a lot of trouble keeping track of how long I use a light. I tend to use it frequently for very brief periods - usually no more than a minute or two and usually on low around the house. If I took it outdoors or used it for any duration on high I'd know to recharge. The way I use it it's hard to tell. I know - test the voltage - I rarely think of it after a 1 or 2 minute usage. You don't tend to notice a drop in output when using low. Too bad the flashlight doesn't have a low voltage warning.

Anyway I'm glad the IMR doesn't run hotter. I bought one just for use in this light. If I like it I'll buy some more. I'll test with the AW 2600 and the IMR and see which I like best.

oronocova said:

Nah I was lucky enough to win the EX with SST-50 in the Christmas giveaway they did. Not sure if it would be the same circuit as the production VX Ultra or not... Mine is H > M > L, starts on H always, ie no memory. I use IMR18650s and they work great!... but it ran ok on the trustfires... I just didn't trust them in the light. You just have to watch the voltage on the IMR cells closer since they are not protected. That goes for any light and any li-ion really though I suppose.

Click to expand...

Ah - my aplogies. Also, congrats!