Help with 2-c ROP

My first attempt at building this "blast from the past" isn't working out so well. I have all the required parts via this forum: 2-c Mag, deep tail cap, etc. I'm running 2 18650's protected,showing 8.5 Volts on the meter. With the low bulb I only get a faint spark and with the high bulb, nada! The bulbs don't seem to fit in the sockets real well but they must be making contact. I'm baffled, any help woulld be appreciated.

Which ROP bulbs -- 3853 or 3854? What specific brand of 18650 cells? Probably with the high bulb of either type, the startup current draw is too much for your protected cells. But since the bulb doesn't light at all, you also seem to have some other issue, probably with continuity. With the 3853L, you probably blew the filament and perhaps the dangling ends are still making intermittent contact. If you have the 3854L, then it should work. Your problem is either continuity, cells that aren't up to the task for whatever reason (not charged, low quality, defective, etc), or a combination of the two.

Why don't the bulbs fit well in the socket, and why do you think that you have continuity?

What brand of batteries are you using? Could be that the PTC can't handle the current draw. Try multiple clicks (flash the light a few times quickly before pressing for constant on).

Bulbs are 3854's,new ultrafire 18650's freshly charged. After several tries multiple clicks light up the low bulb. Still no luck with High. If it's the battery which brand should I try next?

gatorgofer said:

Bulbs are 3854's,new ultrafire 18650's freshly charged. After several tries multiple clicks light up the low bulb. Still no luck with High. If it's the battery which brand should I try next?

Click to expand...

I think AW's will power up the ROP hi. Or you could use unprotected but be careful.

I've been running unprotected 18650's in my 2C ROP without any issues. I only use it in short duration bursts though.

gatorgofer said:

Bulbs are 3854's,new ultrafire 18650's freshly charged. After several tries multiple clicks light up the low bulb. Still no luck with High. If it's the battery which brand should I try next?

Click to expand...

There is your problem. If I recall the 3854 pulls 3A or so, and that my friend is alot of curret for those Ultrafire cells.

Get some IMR 18650 type and most likely thats when you will see that light come to life. The IMR 18650 is rated for 10A.

bigC

gatorgofer said:

Bulbs are 3854's,new ultrafire 18650's freshly charged. After several tries multiple clicks light up the low bulb. Still no luck with High. If it's the battery which brand should I try next?

Click to expand...

There is no protected 18650 in the market to power up a 3854 HO bulb at this point. 3854 HO bulb pulls up 4.2~4.4 Amps at 7.2~7.4 volts.
Get:
1-Pair of AW's protected 18650 to power up a 3854 LO
2-Pair of IMR 18650 to power up a 3853 HO bulb SAFELY.

The only SAFE, PRACTICAL, and LONG RUN way to power up 3854 HO bulb is using 2S/2P protected 18650 in dual bored 2.5D M*g

Thanks ya'll. I'll be ordering some AW IMR's shortly. I'll post a report when they arrive.

I jumped the gun on my reply. Thanks Fiivemega,your products are great. I'm a newbie so bear with me, what are 2S/2P's ? And why a 2.5 D host? And, where can one be obtained?

gatorgofer said:

I jumped the gun on my reply. Thanks Fiivemega,your products are great. I'm a newbie so bear with me, what are 2S/2P's ? And why a 2.5 D host? And, where can one be obtained?

Click to expand...

By boring out the 2.5D M*g, you can accomodate 4 protected (2900mAh) 18650 cells which are connected 2 serial of 2 and then both are connected in parallel.
This will keep the voltage about 7.4 volt but increase the capacity to 5800mAh which means long run, less stress to cells, less frequent recharging, less voltage drop, higher performance and high current capability simply because 2 groups of parallel cells sharing total current draw.
This is old version, this is new version, this is 12AA version of ROP 3854 and this is 2x26500 version of 3853 ROP