ROP w/ 6 1/2 d cells.

[paulsl]

I did my first mod. An ROP in a 4D mag with a 6 1/2D cell stick claiming 4 ah. I loved it but after 15 minutes the voltage really started to lag. After 25 minutes of use the stick measured 6.2 volts. i'm dissapointed in the run time which I thought would be better with this set up. I did the tail spring resistance mod and plan to do a partial switch resistance mod by running the wire in the switch's spring. I followed the instructions exactly but does anyone know of anything I could do to increase run time. I have various hosts and AW's C lithiums. Do you guys think the stick is bad or does it need some use to accept full charge or to be left on for say half an hour after the green light goes on the smart charger? any ideas would be appreciated.

Thx.

 

[leeleefocus]

Try cycling the batteries a few times. You should get much longer run time than that. depending on how good the batteries are with the ROP high bulb you should get atleast 45 mins.

 

[sig-in-tx]

I'm getting the better part of a hour on my sub-c cells. Try cycling them as suggested. Bet they pick up some time.

 

[paulsl]

Thx a lot.

 

[Josey]

The problem could be in the making of the 6-pack. There are factory 5-packs for the MagCharger. Sometimes the seller will weld a sixth 1/2D cell onto that factory 5-pack, but if they don't have the right equipment they can damage the new cell.

 

[JimmyM]

Are these the Aero cells? I cycled mine several times on my BC-8. Is this a soldered stick pack? Maybe some #600-1200 sand paper and ProGold between cells?

 

[mdocod]

I agree with the others here... those cells have probably been sitting in a warehouse for at least a year or more.... They need to be cycled to break up the large "crystal formations" that cause low output voltage under a load... read this thread to learn more...
http://www.candlepowerforums.com/vb/showthread.php?t=157544&highlight=memory
Silverfox really did his homework on that one.

by his recommendation, do some SLOW discharges to get the cells back to tip-top shape again.

The switch mod is also pretty important here, the ROP is a current hungry lamp, anything you can do to lower resistance will have a significant impact on the performance of a high current lamp. Once the cells are broken in, and you get the resistance down, I would expect over 45 minutes of bright output. After reducing the resistance, it might be wise to let the cells rest for a few hours after they come off the charger- it probably wouldn't instaflash, but you'll save yourself a lot of bulbs in the long run by letting it rest.

 

[paulsl]

It was wrapped and made by a co. that sells many 4 ah mag packs. They asked that I not advertise thathey made this since they dont want to make these on a usual basis. They are aero cells[. Should i open the shrink wrapping and do wha you say?

Thanks,

Pablo

QUOTE=JimmyM]Are these the Aero cells? I cycled mine several times on my BC-8. Is this a soldered stick pack? Maybe some #600-1200 sand paper and ProGold between cells?[/QUOTE]

 

[paulsl]

I'll try what you say but how do I do a slow discharge. i am using a 2-12 cell smart charger.

Thx.

I agree with the others here... those cells have probably been sitting in a warehouse for at least a year or more.... They need to be cycled to break up the large "crystal formations" that cause low output voltage under a load... read this thread to learn more...
http://www.candlepowerforums.com/vb/showthread.php?t=157544&highlight=memory
Silverfox really did his homework on that one.

by his recommendation, do some SLOW discharges to get the cells back to tip-top shape again.

The switch mod is also pretty important here, the ROP is a current hungry lamp, anything you can do to lower resistance will have a significant impact on the performance of a high current lamp. Once the cells are broken in, and you get the resistance down, I would expect over 45 minutes of bright output. After reducing the resistance, it might be wise to let the cells rest for a few hours after they come off the charger- it probably wouldn't instaflash, but you'll save yourself a lot of bulbs in the long run by letting it rest.