SPARK SP6 Review (5 x XM-L T6 | 6 x 18650 / 12 x CR123A)

[phips]

I would use the internal (unbalanced) charging system only when in a bind.
When you use protected cells theoretically you should be fine, however I feel the individual cell protection should be a last line of defense an not used on a regular basis.

I have a lithium battery pack for a rc-car where one of the cell exhibits a significantly higher self-discharge rate.
Using a balanced charger the pack works absolutely fine, however if I were to charge it unblanced results would most likely be catastrophic.
While this is not 100% applicable here (no individual cell protection, cheaper quality) it highly discourages myself from handling any lithium rechargeables carelessly.
Although it is probably already careless enough to be still using this particular pack...

[rufus001]

So what does the balancer actually do? I thought the problem was it would shut off charging before all batteries were fully charged if there was no balancer. But from the previous post it appears the balancer alters the current to each battery depending on how discharged it is? Therefore preventing to much current going to a deeply discharged battery resulting in ?

[turboBB]

Balance charging (a feature thus far found only hobby chargers) is able to monitor the voltage of each cell and manages the charge of each individual battery that is charged in series through the means of balancing leads. What it does is to ensure that no individual cell is overcharged by actually discharging any that exceeds the preset limit (and this can vary depending on the chemistry of the batteries in question). It's a bit heavy to go over in a reply so just do a search for balance charging and you can read up on it.

For the record, there is NO balance charging on the SPARK SP6. The charger plugs to the end of the light and charges all 6 cells in series. As such, there is a potential for each cell to be mismatched. The easiest way to understand this is to think in terms of resting voltage not matching between all cells; ie: you can end up with 3 cells at 4.19 and 3 cells at 4.21 as a simple example OR you can end up with any combination of under/over charge for each cell as long as it equals to 25.2V (or whatever is the terminating voltage that the charger is programmed at - I don't know yet since I haven't graphed the charging algo yet). This typically happens as cells age and their internal resistance builds up thus the cells with higher resistance takes longer to charge thus staying lower in voltage while those with lower resistance charge more quickly and thus are prone to overcharging. It's a bit ironic that the one bad cell will actually be safe from overdischarging in this scenario while the healthy cells will take a hit.

So let's say that of 6 cells, 5 are identical in IR and 1 is a bad cell with pretty high IR. Now imagine a scenario where by the time the 5 healthy cells reach 4.2v each (for total of 21v) the bad cell is just at 3.9v thus representing a total of 24.9v. Now let's say that the charger has been programmed to terminate at 25.2v exactly, so the charger at this point will continue to charge all cells since it's programmed for just that and isn't aware of what each cell is at. To make things easy, let's pretend that it'll continue to charge all 6 cells equally to reach 25.2v so that means each cell will get an additonal .05v at which point you now have 5 cells at 4.25v and that one bad cell at 3.95v for a total of 25.2v. Again, as far as the charger is concerned, it's done its job and will terminate charging regardless of what each cell may be at. While 4.25 is overcharged, it's actually still within specs for many cells (which typically state 4.2 +/- .05V). However, now imagine that there were actually 5 bad cells and a single good cell, you can imagine how fast that single cell would fill up and be overcharged badly leading to very undersirable outcomes! This is the potential danger of charging batteries in series without a balancer.

What the use of protected cells will do is that each cell features a protection circuit that will trip in the event the cell is over-charged/discharged. Since each cell features this circuit, you basically have six times the safety redundancy in the event one of these cells has a faulty/bad circuit.

This is why SPARK chose to pick 6 "matched" cells (again, note my caveat in previous reply) of the same type and brand since IR typically has less variation. However, while these Panasonic cells are indeed good quality, they are not protected cells (they lack a protection circuit). They do however feature a PTC thermistor (strangely the spec sheets directly on Panny's site doesn't mention this but I found this one that does) which provides a mechanical safety in the event of high current surge or temperatures.

Please read this great article on Battery University for a full explanation of the safety considerations when using Li-Ion cells (or just pop over to the Electronics sub-forum for many great detailed threads):
http://batteryuniversity.com/learn/a...afety_concerns

In the end, since I'm typically risk averse, I usually like to use protected cells in my lights. However, I ALWAYS check the individual voltage of cells after charging (regardless protected or not) thus do not have any concerns with using unprotected cells as well especially when they are new since the likelihood of them being unbalanced is very low.

I have now run the Panny cells through two cycles and both time all cells were 4.20 (+/- .01) after charging regardless that their ending voltage were not all the same after runtime testing.

However, as they say, YMMV so you'll need to make your own judgement call on whether you feel comfortable/safe using non-protected cells as well as the included charger.

Cheers,
Tim

[phips]

However, while these Panasonic cells are indeed good quality, they are not protected cells (they lack a protection circuit).

I honestly think the internal charger should not be used with these cells at all.
Basically there is not one protection system and 6 links that can break in the chain (7 if you count the charger).

I guess there a two possibilities that could happen:
1) Spark's idea is probably that if single cells get overcharged slightly, the system will balance itself naturally.
2) My scenario though: The lowest capacity cell of the six (the one which will reach over 4.2V first) will get overcharged.
Being overcharged a little every time, this cell will age faster and loose its capacity quicker than the rest and as a result will reach ever higher voltages with every charging cycle.

My first instinct is that Spark must have thought this through, I mean they even shrink-wrapped the cells as to say that this system requires no further intervention by the user.
However I think if you insist on using this charging system I think you should check the individual cell voltage after charging at least every couple of cycles (which is basically what a balancing system does every second).

[rufus001]

Thanks Tim!

[IMSabbel]

Also not a fan of unbalanced in-series charging, here.

Not to mention that 6 batteries is a lot, and you are charging them in a metal pipe without burst valves.

[Albert56]

The "interesting" thing is that it starts out at 500 lumens and then "slowly" ramps up to 3K lumens over a span of 2 minutes???


Unless I'm misunderstanding you here, this is not "interesting", it's a major flaw and a deal breaker. Forgive me, but at this price point, I expect an led flashlight to turn on at or very near it's full rated output when I press the switch, not 2 minutes later! I don't need to wait for my TN-31 or RRT-3 to warm up. I could buy a cheap HID light for a lot less if I wanted a delay in achieving full output. I'm surprised that no one else has commented on this. I think I'll be passing on this light.

[turboBB]

You're taking the statement out of context... If you look at the runtime chart, the ramp up is not linear over that span. It goes from 500lms to about 3000lms in 2 seconds and then ramps from there to about 3200.

SPARK has not touted this as a feature so I'm uncertain if it's a flaw or by design, in which case if it was the latter, I'm not surprised as a few of the high output multi-emitter lights feature this (e.g. XTAR S1, TN30...).

Besides most of us would never notice the ramp up (at least on the SP6) if it were not for test equipment to capture this. Let's think of it pragmatically, at night if your eyes were dark adapted, you'd actually appreciate a slow ramp up especially at these output levels.

I'll find out if this was in fact by design or a flaw on my sample, in the meanwhile, I'd like to hear back from current owners on whether or not they notice this ramp up.

Cheers,
Tim

[warmurf]

That ramp up time isn't a flaw and really isn't any issue. I am concerned thought about the unbalanced charging potential, however as someone said above, take them out every second charge and check them should work? So far I'm not seeing anything against buying this light, except the price. I may need to list some lights for sale.......

[IMSabbel]

Well, the review was not conclusive in terms of ramp-up speed. It just mentions that it takes "2 minutes" to go from 500 lumen to 3000+ lumen.

And yes, 2 seconds would be tolerable (if not optimal), but it is still a flaw. 2 Minutes would be a disaster.

The instant on (allowing the use of intermediate light) is one of THE advantages LEDs have in very high output lights like these compared to HIDs (I own a HID that takes about 20s to get to full power and thats really annoying).

[rufus001]

It's a non issue for me. I haven't even noticed it before or after Tim mentioned it.

[turboBB]

@warmurf - as mentioned, I've not experienced any issues but then again, I've only gone through two cycles and the cells have all been within +/- .01v of each other. If one takes extra precautions (not overdischarging, checking cells after charging, being around and monitoring while charging) then I feel the risks should be reasonably low, although not completely gone. For additional safety, you may elect to swap out the unprotected cells with protected ones of the same brand and age as an added safety measure. However, in spite of this, you should still check the voltage of each individual cells after every few charges. I've been pretty swamped but I hope to graph the charging algo shortly.

@IMSabbel - I'll update the review to clarify but thanks for bringing it up.

@rufus - thx for your feedback.

[warmurf]

Thanks Tim. I couldn't wait any longer for the full review- I've pulled the trigger....

[baldo21]

The inclusion of Good quality but unprotected and low capacity batteries,
combined with the unbalanced and unreliable charger is a clever camouflage to justify the high price tag.
I am sure the SPARK SP6 would sell much better if optionally offered without the batteries and charger but at a more realistic price.

[turboBB]

For those not interested in the SP6 due to the packaged arrangement, I'd suggest you voice it over on CPFMP or to contact SPARK directly. Perhaps if there is enough of a response they may consider it so it couldn't hurt to ask.

[Albert56]

"You're taking the statement out of context..."


Sorry, my bad... I glossed over the "2 second" part. However, charger/battery issues aside, what kind of throw does it have? I'm not looking for another high power area light. It's reflector doesn't seem particularly deep and I've seen the phrase "wall of light" applied to it. Personally, I think the manufacturers should start concentrating more on throw vs raw lumens. I considered the SR95UT, but it's really large and out of my price comfort zone. I'm looking forward to some outdoor beamshot comparisons of the SP6 against other lights. Thanks for the nice review.

[turboBB]

All, bulk of Design/Features section now added (I'll wrap up battery carrier and charger next).

@Albert56 - nope, that would actually be my bad. I should've been a bit more clearer but thanks to the follow up questions here, I've updated the review. Not sure if you've seen my Memorial Day Camping Thread but the SP6 would slot between the TN30 and XTAR S1 in throw but will have the brightest spill. Take a look at the beach shots and if you think you like the output on the XTAR S1 or TN30, you will likely be impressed by the SP6.

Again, this is why I think SPARK is on to something with these side firing emitters as it allows pretty decent throw despite having a relatively shallow reflector.

I'll be back at that same camp spot in a few weeks after which I'll have a massive comparo thread again.

Cheers,
Tim

[warmurf]

OK,

So I've decided I'm going to swap out the batteries it's comin with, if for no other reason but for extended run time (looking at the graph with the Xtars- a 10 minute difference on high) but need to
decide what to replace them with. I have 2900AWs already so that would be an easy choice.

Any recommendations for the best suit for this light, for both output and running time?

[rufus001]

I'll be back at that same camp spot in a few weeks after which I'll have a massive comparo thread again.

Cheers,
Tim

Woohoo!

[Jabberwocke]

O.K. returning member that forgot his password. Last seen here with 2006 Surefire U2 (still works). Ordered SP6 and am worried about using included unprotected batteries. Plan to buy some Xtar 3100 and replace the originals. Are the originals safe to use in a parallel light such as a TM11 ? Would use external charger such as Pila. Any thoughts ?

[turboBB]

@warmurf - given the high voltage, the draw is actually very reasonable. I measured roughly 1.6A draw on Max so I'd recommend using HKJ's excellent cell comparator:
http://lygte-info.dk/review/batterie...comparator.php

and selecting the 2A button then clicking through various cells to see which gives you the best runtime (longest line) or highest v output (tallest line overall) depending on your needs. I used to think that just 'cuz a cell was higher in capacity and was able to best another cell at a higher draw that it'd naturally beat it at lower draw but as you play around with his tool, you'll come to see that's not always the case.

@Jabberwocke - welcome back from your hiatus! The cells feature button tops so can be used in the TM11 but again, with the usual caveats that go along with using unprotected cells. Despite its parallel arrangement, there still is a chance (even if a reduced one) that one cell can be discharged disproportionately from the others. If you follow safe LiIon handling practices (monitoring voltage of each cell after charge, not overdischarging, etc.) then I don't see why these cells can't be used. If however, you'd rather not take a chance at all then I'd recommend just selling them and getting protected cells for your TM11 as well.

Likewise with the charger, per the past few previous replies, if you don't feel comfortable with the potential risks of unbalanced cells then best to remove the batteries and charge them individually with an external charger.

My bottom line on this is that I personally feel comfortable using the supplied charger as well as the unprotected cells since I'm pretty careful about checking cells, etc. but in this litigious society, one would be foolish to recommend that unconditionally to another in case something does happen so ultimately, you'll need to make that decision for yourself.

Cheers,
Tim

[warmurf]

Thanks for the info Tim, very helpful! I'll run the supplied batteries for a while and will decide on a secondary set for longer running after reviewing HKJ's data. Cheers!!

Ricky

[f22shift]

I think the built in charger has its purpose. For example you are on vacation or work and you want a simple solution to top off the cells. Then at home you should individually charge the cells.
I mean it's a plus rather than a minus to have this feature. It doesnt affect the water resistance . It's there when you need it but shouldn't be relied on.

[warmurf]

Yep, totally agree.

The only down side I'm seeing with this light is the performance sag when it get's hot, which looks to be within 15 minutes of start-up on turbo. Un-cooled the drop in output is very significant, and was one of the concerns around this light from concept. That said, there would hopefully not be too many occasions where you'd need to be running the light at full bore for durations such as that, and if you drop it down in output for durations it will probably hold full output for 5-10 minute runs (from the data I'm seeing) and that looks to me to be great for normal use.

The one stand-out for this light is it appears to be one of the best lights for sustained output over duration within the high power class of lights.

[NorthernStar]

I'll be back at that same camp spot in a few weeks after which I'll have a massive comparo thread again.

Cheers,
Tim

That sounds great!

I look forward to see that massive comparo. Hopefully that means that one can finaly see some good longdistance beamshots on the SP6. I am very curious to see how the SP6 compares to the Olight SR92(and the Olight SR95 as well) and the Xtar S1 when it comes to throw and flood.

Edit: I now saw in this thread that some comparsions have been done: http://www.candlepowerforums.com/vb/...ead.php?342542

The SP6 looks like it has a broader beam than the SR95 by judging from those pics at the distance of 100 yards,but it would be great to see more comparsions and at even longer distances.

[Jabberwocke]

I know that I am getting off topic from the SP6 review, but how much unprotected cell voltage imbalance is acceptable ? I understand that the current flow due to imbalance will not be limited by the missing protection PCB, but instead by cell and path resistance. If the resistance is on the order of tens to hundreds of milliohms, then it seems an imbalance of 100mV when charged would be unsafe. Is there a thread on this topic ?

[turboBB]

Short of the whitewall/outdoor shots (and potentially some add'l runtime testing), this review is now wrapped up. Tons of new material added along with full Charging graph and details (search multiple instances of 8/18). If you can't be bothered to go back to OP, my opinion on the charger is that it's quite good, exhibiting a very good CC/CV charge curve.

Cheers,
Tim

[jake25]

Very interesting a good CC/CV curve.

[selfbuilt]

Tons of new material added along with full Charging graph and details (search multiple instances of 8/18). If you can't be bothered to go back to OP, my opinion on the charger is that it's quite good, exhibiting a very good CC/CV charge curve.

Hi Tim, outstanding review. Very thorough and detailed, nice job.

I'm glad to see you did the detailed charging current/voltage testing. I haven't bothered, given that you need to set everything up outside the light (as you thoughtfully did). And as you pointed out, the ~2.1mA drain from the battery indicator shouldn't be an issue for this kind of testing. I too am glad to see the CC/CV pattern.

However, I'm disappointed to see that the charger doesn't terminate when the light goes green. I suspect as much in my review, where I noted that when I left my AW 2200mAh cells connected to the charger for an extra couple of hours they came out at higher voltage. Typically, my charger read just under 25.4V when first green (with all cells < or = 4.23V). But on that extended charge, it came out at just over 25.5V, with all cells between ~4.25-4.26V. So it looks like my unit is willing to charger a little higher than yours. >= 4.25V per cell is definitely beyond my personal comfort level, so I will be recommending people pull the charger as soon as it goes green.

Anyway, great that you actually confirmed it directly. I agree that it's not really an issue at the tail-end of charging, as it should be more than balanced out by the battery indicator drain normally.

Good job!

[turboBB]

Thx selfbuilt! I plan on doing another graph of the charging in the future but in the light just need to figure out how to do it w/out shorting it since the pos/neg contact points are right next to each other. Will post results whenever I get to that.

Cheers,
Tim