AW C-cells and ROP hi
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mudman cj
Flashlight Enthusiast
I have read that the ROP hi can also cause the blob of solder to melt at the base of the bulb. I have seen pics of what it can do to the plastic bulb pedestal, at least the "C" version. I am not sure if it can melt the plastic on the "D" version of the switch assembly, but just to make sure I reduced the resistance of the internal spring assembly by soldering a piece of solder wick (or wire) from one metal cup to the other (at each end of the spring). The reduction in resistance reduces heat build up that results from passing over 4 Amps through a slightly resistive steel spring plus additional contacts. This has the added effect of making the bulb whiter and brighter.
These other types of failures are pretty rare because the light has to be left on for an extended period of time. IIRC it would take more than 30 minutes and maybe an hour. Using electrical contact cleaner like Deoxit can also help reduce resistance and therefore heat build up, while again making the bulb run whiter and brighter.
These other types of failures are pretty rare because the light has to be left on for an extended period of time. IIRC it would take more than 30 minutes and maybe an hour. Using electrical contact cleaner like Deoxit can also help reduce resistance and therefore heat build up, while again making the bulb run whiter and brighter.
mudman cj
Flashlight Enthusiast
Here is the best deal I have found on enough Deoxit for you and a friend to last for many years. Use it to clean oxidation that forms on many types of metal surfaces wherever an electrical contact is formed.
You can remove the spring to get down to the upper switch contact. Then also hit the spring and cup that contacts the bulb base. Apply it to the bulb contact, the battery anode (+) contact, and why not the battery contacts too? Then there is the top of the tailcap spring and the bottom. But why stop there? You can then get out the soldering iron and add 'jumpers' to reduce both the length and resistivity of the conducting paths. Google search on 'resistance fix' for related threads with pics and instructions on how to reduce resistance further in the switch and tailcap.
You can remove the spring to get down to the upper switch contact. Then also hit the spring and cup that contacts the bulb base. Apply it to the bulb contact, the battery anode (+) contact, and why not the battery contacts too? Then there is the top of the tailcap spring and the bottom. But why stop there? You can then get out the soldering iron and add 'jumpers' to reduce both the length and resistivity of the conducting paths. Google search on 'resistance fix' for related threads with pics and instructions on how to reduce resistance further in the switch and tailcap.
You might consider download's aluminum C tower for better heat dissipation:
http://candlepowerforums.com/vb/showthread.php?p=2069029#post2069029
I bought a couple and installed one. Can't say I noticed any difference, but it make me feel better.
http://candlepowerforums.com/vb/showthread.php?p=2069029#post2069029
I bought a couple and installed one. Can't say I noticed any difference, but it make me feel better.
Supernam
Enlightened
As far as the battery goes, it can handle it. I haven't ran my ROP Hi 2C for longer than 1 minute at a time. I can't remember who, but there is a metal PR socket so that you won't melt the plastic one.
jimjones3630
Flashlight Enthusiast
Hi cj,
do you know if there is a difference in conductivity between pro-gold and deoxit? think both are made by same company.
jim
do you know if there is a difference in conductivity between pro-gold and deoxit? think both are made by same company.
jim
mudman cj
Flashlight Enthusiast
Hi Jim,
Deoxit removes the oxides and Pro-Gold protects the surface against them reforming. They are both made by Caig Industries (caig.com), and they have many products available as mixtures of varying proportions of these two products.
Deoxit removes the oxides and Pro-Gold protects the surface against them reforming. They are both made by Caig Industries (caig.com), and they have many products available as mixtures of varying proportions of these two products.
jimjones3630
Flashlight Enthusiast
Thanks cj
mudman cj
Flashlight Enthusiast
You are very welcome Jim. 
And while I am posting I thought I would give a +1 to Supernam's comment about the batteries handling it.
I ran them on the 5761 which can draw 5.5 Amps to the ROP hi current of 4.3 for 28 minutes straight and immediately took a temperature reading with a thermocouple between them and a towel wrapped around the outside. They were warm but within safe territory even assuming that the middle was 10 degrees hotter than the outside.
And while I am posting I thought I would give a +1 to Supernam's comment about the batteries handling it.
I ran them on the 5761 which can draw 5.5 Amps to the ROP hi current of 4.3 for 28 minutes straight and immediately took a temperature reading with a thermocouple between them and a towel wrapped around the outside. They were warm but within safe territory even assuming that the middle was 10 degrees hotter than the outside.
Okay so the heat shouldn't be a problem, even though there are some reports of there being a heat problem. And some preventitive measures that can be taken. That's the thing about these kinds of discussions, you can't really ignore the outliers as that tells you something about the distribution of events. I'll probably do something with the C Li-Ion at some point but it just doesn't strike me as a cell as fool proof as the AW P18500 or P18650. And it strikes me that a greater knowledge base and tinkering propensity is required to manage the C li-Ion cells in an ROP application.
It does strike me as a great cell though for the next level of flashaholism.
It does strike me as a great cell though for the next level of flashaholism.
mudman cj
Flashlight Enthusiast
Well, I was concerned but went ahead in the name of science. I knew they had a thermal PTC built in for protection against thermal runaway, but there was certainly still some risk that it wouldn't work. In the end I decided to take one for the team, because somebody had to try it first.
Also, the current doesn't remain at 5.5 Amps the whole time. I could try to calculate an estimated plot of current vs. time based upon the bulb characteristics and the bulb voltages I measured, but I have not had good enough reason to do so yet. I am curious though...
Even though there aren't major heat concerns with the cells in an ROP, there are definitely still other heat concerns. I would be concerned about the pedestal melting and the bulb solder melting, especially without some work to reduce resistances.
Also, the current doesn't remain at 5.5 Amps the whole time. I could try to calculate an estimated plot of current vs. time based upon the bulb characteristics and the bulb voltages I measured, but I have not had good enough reason to do so yet. I am curious though...
Even though there aren't major heat concerns with the cells in an ROP, there are definitely still other heat concerns. I would be concerned about the pedestal melting and the bulb solder melting, especially without some work to reduce resistances.
Never mind I just found your thread on it, you terminated at 6V.
http://www.candlepowerforums.com/vb/showthread.php?t=160048
http://www.candlepowerforums.com/vb/showthread.php?t=160048
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