Big D bulbs?

What are the difference's in the two? Is one better than the other?

http://www.brightguy.com/accessory_results.php?Sku=PEL3850071245

The lead acid set i believe, pulls more power and gives a brighter output while the nicad version is less.

If you're building a ROP m@glite, you will want to use the lead acid set.

Hmmmm...both the nicad and lead acid bulb says 24 watts for high, and 11 watts for low. So how can one pull more power then the other? :thinking:

They are advertising that the Nicad high bulb is 610 lumens, where the lead acid bulb (#3854) is 600 lumens.

Also the Nicad Big D flashlight they sell have a longer run time of 1.25 hours vs. the lead acid Big D flashlight of 1 hour. So the Nicad battery have more current right?

Interesting thread. I may just have to test the nicad bulbs in my ROP.

Both pull 4A; the nicad at 7.2V, the SLA at 6V. The Nicad Big D has longer runtime because the pack is 5Ah capacity; the SLA is 4Ah. Overdriving the SLA at 7.2V produces ALOT of output, over 1000 bulb lumens. I'm talking about the high output versions in both cases; there are corresponding lower output versions for each type of Big D; they're no slouch, either.

Ahhh, that answers that! Thanks Phaserburn. That means that nicad bulb would work great with my 7 AA setup! :devil:

Phaserburn said:

Both pull 4A; the nicad at 7.2V, the SLA at 6V. The Nicad Big D has longer runtime because the pack is 5Ah capacity; the SLA is 4Ah.

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so would I correctly assume that the ones most people are using are NICAD and thus the 500 odd lumen output? If the SLA were used at 7.2 they would probably blow pretty quickly right?

The original ROP 4D used a 7.2 V Sub-C battery stick to mildly overdrive the 6 volt SLA bulbs.

thanks lumenhound.

Phaserburn said:

Both pull 4A; the nicad at 7.2V, the SLA at 6V. The Nicad Big D has longer runtime because the pack is 5Ah capacity; the SLA is 4Ah. Overdriving the SLA at 7.2V produces ALOT of output, over 1000 bulb lumens. I'm talking about the high output versions in both cases; there are corresponding lower output versions for each type of Big D; they're no slouch, either.

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something doesn't add up. if both pull 4A and one is 7.2V while the other is 6V; they shouldn't both be 24W (as is stated on the web-site).

lexina said:

something doesn't add up. if both pull 4A and one is 7.2V while the other is 6V; they shouldn't both be 24W (as is stated on the web-site).

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Agreed, lexina. The Nicad bulb should be rated at 28.8W. I don't know why Pelican states something that is obviously not true. I even called them about it and spoke with their engineering dept, to no avail. They only rate a 10 lumen difference, too.

:shrug:

Lol don't know what's going on now =/

Here's a link to Pelican's website, on the Big D alkaline light.

http://www.pelican.com/large_lights/la_big_d_alkaline.html

Notice description says "24 watt xenon" and then directly under, in the table...it states "8 watts". Weird i tell you :huh2:

Here's the link to the official ROP homepage
http://lights.lightrefineries.org/?page_id=9
and that also says the alkaline replacement kit comes with "8 watt bulbs".

Ok now i'm really confused...maybe the alkaline replacement set comes with the "28.8" watt xenon and an 8 watt low output vs the SLA 24 and 11 watt bulb set ?

I didn't notice it tell after I placed my order, I ordered the Rechargeable NICAD bulbs. Part Number: PEL3853 So now I'm not sure what to feed it? Did I mess up?

Well, the traditional ROP design calls for the SLA bulbs, part number 3854. As i understand, the Nicad's high output bulb is designed for 7.2V or so, meaning if you use 6 rechargeable batteries, the bulb won't be overdriven and will just produce stock lumens (i think 600 or so). The SLA high output bulb is 6V, hence a 6 rechargeable cell equipped light will overdrive it to roughly 1100 bulb lumens. That is what i've read. GL

sig-in-tx said:

I didn't notice it tell after I placed my order, I ordered the Rechargeable NICAD bulbs. Part Number: PEL3853 So now I'm not sure what to feed it? Did I mess up?

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The SLA 3854 are 6V and would be over-driven on 6AA NiMh to give a brighter and whiter light. Your Nicad 3853 are 7.2V and should work well with 7AA Nimh and a dummy cell in an 8AA-2D adapter.

I was thinking about a 6-pack of sub c cells. Guess I will need to order the rite bulbs this time. Will 6 sub c drive it ok?

Theorotically, 6 cells in your battery pack for 7.2V @ 1.2V each...with the 3853 bulbs you ordered, high output bulb being 7.2V rated...your battery pack will drive the bulb at it's intended level, meaning roughly 600 bulb lumens, after optical losses, expect about 350 output lumens. If you use the 3854 bulbs next time, expect about 700 output lumens. Btw, your battery pack fresh off the charger will measure a fair bit more than 7.2V, but will sag down once the load is applied.

Any one have any better ideas to drive the bulbs better? I was thinking about a couple of 18650a I took out of a old laptop, but being a unprotected cell I'm a little gun shy. I have a ice charger so thats not the problem. Just been reading about to many loosing a car, house when things go wrong. So unless any one has any better ideas I think I will go with six sub c cells. Guess I will order the correct bulbs tonight. Just ant no fun if I'm not overdriving it.

sig-in-tx said:

Any one have any better ideas to drive the bulbs better? I was thinking about a couple of 18650a I took out of a old laptop, but being a unprotected cell I'm a little gun shy.

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That's the ROP LE, but the bulbs may demand more current than your salvaged cells can provide.

HammerSandwich said:

That's the ROP LE, but the bulbs may demand more current than your salvaged cells can provide.

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Ive kind of decided not to go that route anyways. Too many what ifs. Going to pick up a 6 sub C pack in the morning.

Will the sub-C stick (6 cell configuration) require magnets to make contact, or do they have nipples?



Excellent thread...