Problem with Light Cannon and NiMh batteries?

[dc4bs]

I have a slightly different question.

I've always used Alkaline batteries and never had a problem with burn times or fuses...

My issue is that the light has started to 'flicker' no matter how new/old the batteries are.

It comes on just fine every time but when it comes up to full, bright, white light, it gives off dimmer, orange flickers every second or two. It's really annoying after a while.

It seems like the starter circuit mentioned earlier is visibly sparking over and over. If so, is there any way to fix it?

Do I need a new bulb/ballast?

 

[plsdiver4377]

Have any of you used the Light Canon with the rechargeable battery pack, made by UK.

I was thinking about getting it, to save $$$ on batteries, but someone told me that when it runs out of juice it dies very quickly. As in one minute there's light, next minute it's dark.
As oppossed to batteries, where when they start to die the light will start to dim.

Is this true?

both mine and my wifes LC's and they have been on 3 night dives or about 1hr50min burn time without them dying on us. I'm actually going to kill them soon in order to check the burn time as well as condition the battery pack. As far as the light dimming versus dying I have no idea yet.

 

[Saturation]

I have a slightly different question.

I've always used Alkaline batteries and never had a problem with burn times or fuses...

My issue is that the light has started to 'flicker' no matter how new/old the batteries are.

It comes on just fine every time but when it comes up to full, bright, white light, it gives off dimmer, orange flickers every second or two. It's really annoying after a while.

It seems like the starter circuit mentioned earlier is visibly sparking over and over. If so, is there any way to fix it?

Do I need a new bulb/ballast?

Mostly likely a bulb issue. Try first reseating the bulb. If this doesn't work, swap it out at the LDS with a known good one and take it from there. Don't worry about buying a new bulb mail order, few have price breaks on this near $100 bulb so your LDS bulb maybe just as good, considering you can test it before you buy it.

As for NiMH, I just use RadioShack variety, and it works well. Over 50 dives with the LC, and roughly 100 hours of burn time on these batteries. I get 2 hours of burn time per charge consistenty.

 

[Greg_Manko]

How many hours on that flickering bulb?

 

[Otter]

No problems and all they said was that the ballast was defective and apologized for the inconvenience. Since this was its first dive, I am going to run on Alkaline for a couple of dives and THEN switch to the 4500mh NiMH to see what happens.

 

[illumiGeek]

Genesis,

The LC ballast is not regulated (light and color will change as batteries drain). The higher powered WA ballasts are regulated, but the 10W ones are not. And NiMh batteries are typically 1.3-1.35v under load (not 1.2 as rated), so the actual voltage is probably what fresh alkalines deliver (minus load drop). Possibly a bit higher, but not enough to kill the light IMO.

Some general info about the UK LC100 and WA Solarc 10W lamp/ballast:

Battery voltage will affect brightness and color temperature. As voltage sags brighness will go down, and color temp will get COOLER (more blue). Kinda backwards from incandescent lamps which get warmer (more yellow-orange). Ifukuda, was your light a lot brighter, and warmer in color? That could indicate an overdrive problem.

WA says its bad to run the light at more than 11W or less than 8W output. 10W is optimal for the rated life. Lower will last longer, as long as it's more than 8W. A 10% overdrive (11W) will shorten the lamp life by 50%. The lamps is rated for "up to 1000 hours" or 500 strikes, so turning your LC on and off repeatedly is not a good idea. If the batteries are weak enough to have trouble striking the lamp, replace them. And when the light gets dim enough to flicker, TURN IT OFF. Running it until it goes dead is BAD for the lamp (especially with Alkaline cells).

I'm not 100% certain, but I believe the LC uses the 10.2V WA ballast. UK specs rate the light at 10V/1.25A, so it seems to be the lower voltage ballast. 8xC Alkalines do = 12V, but Alkaline batteries are poor at delivering any kind of reasonable current (they work best in devices that draw only a few 100 milliamps). Under the load of the LC ballast they are probably dropping to 1.2/1.3v per cell.

NiCad and NiMh rechargeables start out at around 1.2/1.3v per cell, but can deliver several AMPs of current with no significant drop in voltage. They also hold their voltage better over time (very flat discharge curve) so light stays more consistent.

One possible problem with NiMh is that fresh off the charger they can deliver 1.4/1.45v per cell, and if the LC is using the 10.2v ballast as I suspect, then this would be over-driving the ballast/lamp. This initial voltage is not just no current surge voltage and will last a while even under load (at least several minutes), but how significant this overdrive is to the LC is unknown. WA states that a 10% overdrive will shorten the lamp's life by 50% (but that's with continuous overdrive). This may be why UK chose lower capacity NiCad cells for their rechargeable pack (NiCad fresh voltage is 1.3/1.35 and falls off very quickly to 1.2/1.25).

That having been said, I too use NiMh batteries in my LC and have had no ill effects. In fact, I find that the LC performs much better on the NiMh. Start up times are significantly less, and both brighness and color temp are more consistent. I modded mine to run on AA NiMh batteries (because I already have a lot of them) and with 2300mA batteries I get around 2 hours run time (maybe a bit less). It's much lighter in weight as well (almost neutral in salt water). Also, the batteries are held more firmly in place by my PVC & duct tape kludge holder, so a bump in the wrong direction doesn't cause the light to extinguish. This little quick and dirty AA mod worked out better than I had expected.

Aloha, iG

 

[Saturation]

That having been said, I too use NiMh batteries in my LC and have had no ill effects. In fact, I find that the LC performs much better on the NiMh. Start up times are significantly less, and both brighness and color temp are more consistent. I modded mine to run on AA NiMh batteries (because I already have a lot of them) and with 2300mA batteries I get around 2 hours run time (maybe a bit less). It's much lighter in weight as well (almost neutral in salt water). Also, the batteries are held more firmly in place by my PVC & duct tape kludge holder, so a bump in the wrong direction doesn't cause the light to extinguish. This little quick and dirty AA mod worked out better than I had expected.

Aloha, iG

Nice detailed analysis iG. Hopefully the new high powered LED provide more reliability and equal brightness to a HID. Do you know anything about them and can comment?

These types were released around 2002-3 and can output > ~3W per LED at the same color as HID but without HIDs startup electronics and their weaknesses. Unlikely their low power cousins, these LED consume as much power as an HID or incadescent. The only electronics they need is a current source to provide stable current across the battery voltage.

I saw UKs new 6W LED handheld and it can give the LC a run for its money!
I haven't used it at depth, but I made side side comparisons of color and brightness. It also does not come with a lantern grip, which I use exclusively. However, at $100 retail, it cost as much as an HID bulb, so when my LC crumps I may replace it with a eLED and put the whole thing in the LC case.



http://www.uwkinetics.com/promos/DS_UK6weLED.pdf

 

[illumiGeek]

The high power LED lights are running Lumileds Luxeon LED emitters. They are available in 1W, 3W and 5W varieties. With proper heat sinking they can be significantly over-driven, but brightness doesn't increase proportionatly, so it's best to run them near spec.

It's the "proper heat sinking" thing that's really the catch with diving lights. In a sealed, plastic light there is no place for the heat to go, so keeping a 5 watter cool enough would be quite tricky (they do get very hot).

I have not seen the 5W C4/C8 versions yet, but the 1W 4AA version has practically no heat sinking, and is run pretty under-driven. Not impressively bright, but very long run time. The regulation is excellent. The light will run at full brightness for 10-12 hours, and several days (continuous) after that at diminishing brightness.

I'd like to get ahold of one of the 5W versions to test in my C4. If I do I'll let you all know what I find.

As for the Light Canon, it can be a bit finicky, but I think it's worth it. The light output is really wonderful. I have heard horror stories about how fragile it is, but mine has been dropped more times than I care to recall, and I'm still running my original lamp. The only real gripe I had was the way it would go out if bumped the wrong way. UK should have really designed some kind of battery holder instead of just stacking them in loosely. I doesn't take much of a bump to cause the batteries to break contact, and <poof>, no light. With a conventional lamp it's no big deal. The light flickers and comes right back on. But with the LC it goes out, then you have to turn it off, wait 3+ seconds for the ballast to reset, then turn it back on.

An unexpected side benefit of my AA mod is that the battery adapter I made holds the batteries in place pretty well, and the light keeps burning through most bumps and jars now. If I ever need longer run time I'll probably spring for NiMh C cells, but for now I'm happy with my little mod.

 

[Saturation]

The high power LED lights are running Lumileds Luxeon LED emitters. They are available in 1W, 3W and 5W varieties. With proper heat sinking they can be significantly over-driven, but brightness doesn't increase proportionatly, so it's best to run them near spec.

It's the "proper heat sinking" thing that's really the catch with diving lights. In a sealed, plastic light there is no place for the heat to go, so keeping a 5 watter cool enough would be quite tricky (they do get very hot).

I have not seen the 5W C4/C8 versions yet, but the 1W 4AA version has practically no heat sinking, and is run pretty under-driven. Not impressively bright, but very long run time. The regulation is excellent. The light will run at full brightness for 10-12 hours, and several days (continuous) after that at diminishing brightness.

I'd like to get ahold of one of the 5W versions to test in my C4. If I do I'll let you all know what I find.

As for the Light Canon, it can be a bit finicky, but I think it's worth it. The light output is really wonderful. I have heard horror stories about how fragile it is, but mine has been dropped more times than I care to recall, and I'm still running my original lamp. The only real gripe I had was the way it would go out if bumped the wrong way. UK should have really designed some kind of battery holder instead of just stacking them in loosely. I doesn't take much of a bump to cause the batteries to break contact, and <poof>, no light. With a conventional lamp it's no big deal. The light flickers and comes right back on. But with the LC it goes out, then you have to turn it off, wait 3+ seconds for the ballast to reset, then turn it back on.

An unexpected side benefit of my AA mod is that the battery adapter I made holds the batteries in place pretty well, and the light keeps burning through most bumps and jars now. If I ever need longer run time I'll probably spring for NiMh C cells, but for now I'm happy with my little mod.

Thanks iG for the analysis and please inform us of any new findings you have.

For balance, let me say I've had a LC since 2002, and it has served me well up to 150' deep. It has about 70 dives on it since its used primarily as a backup for my canister. I dropped it once from 3' to concrete and that shattered the $80 bulb. Its been fine since, but I would not drop it again. I've dropped it to sand and grass without issues. With C cells in the unit, I and other LC users have not had issues with batteries breaking contact with bumps.

Generally I've not had issues with high wattage devices underwater since the water acts as a coolant ... key is to only use the device in-water. Cannister HID can get hot, to their rated wattage, and I'm told sustaining this type of heat can shorten bulb life.

 

[illumiGeek]

I use my LC100 out of water frequently and it seems no worse for the wear. It really doesn't get very hot.

As for the bump issue, it doesn't happen often, but it's really annoying when it does. The first time it happened I had dropped the light while trying to juggle too many things with too few hands (I could use a couple extra). The LC was attatched to my arm with the lanyard, so it didn't fall; it swung down and whacked my hip, and <poof> no light. It really didn't hit all that hard, but since it was the first time I had banged the light a feeling of dread and visions of a ruined $80 lamp came over me. So what did I do? I turned it off, and right back on again, and nothing! And then, as panic was about to set in, I turned it off again, and as I was about to turn it back on, sanity suddenly returned and I remembered the off/reset time and waited 5 seconds, and of course it worked like a champ after the wait.

Another time I intentionally let it fall to the lanyard. I needed both hands for something, and new the light was secure so I let it slip through my fingers and the lanyard caught it and it swung upside-down and went out. That time it didn't even bang into anything. ??? Just swung down and went out.

I mean I know it's not an expensive light by HID standards, but a simple battery holder would solve that problem and shouldn't add much to either price or weight.

Now as for unintentional major falls, well... I guess the worse one was when it fell from the top of my 19" monitor, bounced off of my computer desk and dropped to the floor. Wasn't on that time, and is still working fine after that fall <whew>.

So why was it on top of your computer monitor, iG?

Umm... well... it wasn't me, you see. It was my, um, room mate. He was playing with it because I won't let him play with his real ray gun in the house...

iG