gholston_matt Posted April 12, 2008 Share Posted April 12, 2008 I was helping another guy with a flash issue today, and it got me to thinking about something that had crossed my mind before.... Does anyone have any first hand experience with operating a Nikon speedlite such as an SB-800 or SB-80DX above the rated operating voltage of 6vdc... Say 7.5 or 8VDC.... I am not looking to try this on one of my own strobes w/o some hard info as to the outcome, but I have seen some folks online claiming to use 7.2v battery packs, and what i am asking is where is the line to be drawn... How capable is the voltage regulator in the Nikon speedlights? Can it deal with 8v from a SLA battery rather than the normal 6v.... This would certainly give you longer battery life until the cell was ehausted... and as a bonus probably 10%-15% faster recycle times as even though the regulator was holding the charge voltage to 6vdc, it would be at 6 volts constant rather than like with the AA cells or Alkalines where the voltage drops over time down more and more... Even "dead" the 8 volt battery would still be at like 5 volts...and if you did not care for the welfare of the battery, you could draw it down to 3 volts or so till the strobe cut off... but that would be hard on the battery. Just a thought... I would like to hear from others that may have tried this....rather than a High Voltage Pack as I need Long Runtime more than anything... RMG Link to comment Share on other sites More sharing options...
gholston_matt Posted April 12, 2008 Author Share Posted April 12, 2008 BTW, I do understand that one could get an external voltage regulator for the 8 or 12v battery to get it down to 6v, but I want to know what the internal regulator can handle without extra circuitry. Thanks Again, RMG Link to comment Share on other sites More sharing options...
Ed_Ingold Posted April 12, 2008 Share Posted April 12, 2008 The SB-80 has an option for a fifth battery, so the maximum battery voltage is 7.5 VDC. The gains from the extra battery or an external low-voltage power supply are minimal - largely added capacity rather than improved speed. If you want a substantial reduction in recycle time, then use an high voltage power supply (e.g., Quantum 2*2), which provides charging power directly to the capacitors - about 325 VDC. If you don't need the added speed (and capacity) of an high-voltage power pack, I suggest you just carry an extra set or two of AA batteries. Link to comment Share on other sites More sharing options...
ellis_vener_photography Posted April 12, 2008 Share Posted April 12, 2008 you might want to read this link, http://www.aljacobs.com/THE%20BLACK%20BOX.htm He seems to know a whole lot about batteries and shoe mount strobes: Link to comment Share on other sites More sharing options...
gholston_matt Posted April 12, 2008 Author Share Posted April 12, 2008 I am familiar with Al Jacobs, and yes he is very knowledgeable about batteries... And I understand that for recycle time I would want a HV pack like the Quantum Turbo or a Lumadyne, etc. What I am asking, is say I am needing to run a flash unattended in optical slave mode for days at a time with no AC power avaliable... If I could hook say an 8 volt battery to my strobe rather than a 6v...then my runtime would be longer because the voltage would stay in the working range longer. My calculations show that a 8AH battery like AL builds into his Black Box might run a strobe on SU-4 mode for about 15 Hours (whereas from experience 4AA batts last about 4 Hours) Of course I could get a real big 6v battery, like a golf cart battery, to make the strobe be able to run for about 15 days... but for the sake of portability, I was wondering if a smaller lighter sealed 8 volt battery might be a better compromise than the giant 275AH golf cart battery? Oh, and if the SB-80DX has an option for a 5th battery...its news (good news) to me. My SB-800 strobes have this option, but I was not aware that the SB-80DX could also do this? Please cite some reference that would show me how to retrofit the 5th battery door onto my older strobes. Would I need to buy the replacement doors that fit the SB-800? My older strobes were not supplied with them when new. Thanks, RMG Link to comment Share on other sites More sharing options...
Ed_Ingold Posted April 13, 2008 Share Posted April 13, 2008 The drain on the internal AA batteries is very low when you use an high voltage power pack. I've made nearly 600 pops on a single set. The life expectancy is a combination of the number of flashes, internal power consumption (e.g., keeping the flash "awake") and self-discharge. NiMH batteries have an high self-discharge rate. This could be overcome by using non-rechargible Lithium AA batteries in the flash. The original Turbo uses a lead-acid battery and the Turbo Z a Ni-Cd battery, both of which have a very low self-discharge rate. This may work for you if the number of pops is under about 200 in that time frame. If this is a remote operation, the key to long life is to allow the camera and flash to "sleep" until needed. One solution is to trigger the camera with a Pocketwizard, which has an option to "wake up" the camera on demand. Link to comment Share on other sites More sharing options...
gholston_matt Posted April 13, 2008 Author Share Posted April 13, 2008 With the Nikon flashes, the flash that is mounted on camera can in fact go into sleep mode... However, my other slave units that are not connected to the hot shoe, are not able to go into sleep mode due to the limitations of the Nikon CLS... In this setup, I have one camera w/ SB-800 mounted in a box attached to a tree... then I have (3) more SB-800 units acting as slaves in DIY weatherproof enclosures to light up the entire area in front of the camera when my infrared sensor is tripped by a wild animal... My idea, rather than to use a HV battery pack on each strobe, was to buy one large 6v battery and wire all of the flashes to it in parallel with buried cables so that NO AA cells would be involved... then I could just charge up that battery every 3-5 days or so... My Camera has the battery grip with an EN-EL3 + EN-EL4 combo, so it will last a very long time when on standby... I have even considered using a Brunton solar cell product to charge the trickle charge the battery so it can maintain its charge even longer. IF I use a pocket wizard, do they have a sleep mode? How long will the cells in them last? I thought that with them being radio based that would drain AA batts faster than my SB-800 with its ability to sleep. I appreciate your input, RMG Link to comment Share on other sites More sharing options...
gholston_matt Posted April 14, 2008 Author Share Posted April 14, 2008 Is there anywhere that I can download a service manual or a schematic for my strobe so that I can determine this information for myself? Link to comment Share on other sites More sharing options...
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