# DIY mod to Nikon SD-8a for more flash power



## jstuedle (Oct 20, 2008)

A lot of Nikon shooters are hooked on the CLS flash system as am I. I use a few SB-800's and find them very powerful and the auto wireless TTL is almost always spot-on. When my remote flash is out of range for the CLS TTL system, I fall back to the Strobist method and the trusty pocket wizard. In addition to the 3 SB-800 units, we also use 2 SB-28's and 2 SB-80DX units with the Wizards with great results. Sometimes we need more flashes or faster recycling than the 4 or 5 AA batteries can provide. That's when the SD-8a power pack comes in handy. It fits in a shirt pocket and adds 6 AA batteries to the SB's internal 4 giving a high voltage boost and cutting recycle time from over 5 seconds to under 2. The number of flashes is also boosted to about double. In rare occasions I have needed more flashes than even this combo can provide. Hence the DIY mod I implemented.

If you have seen the "fake" battery concept used by Quantum or Al Jacobs, then this method will look familiar. 







Here is a collection of all of the parts. The connecters, battery, wire and heat shrink tubing can be had from " onlybatterypacks.com ". The fake batteries are simply 1/2" wood dowel. Add a charger from the same site and you are all set.






A close up of the wiring and construction of the DIY battery adapter.






Make sure the correct fake battery is installed in the proper position. A  small notch will need to be cut into the lower case to permit the wires to pass  through. I recommend reinforcing the wires with a little heat shrink tubing as  shown.






The remaining connecter shown protruding from the case is for charging.






Then it all fits in a used flash case. This one from a SB-80DX. The cases drawstring is great for hanging from a knob on a light stand.


Use care if you attempt this mod, you will void the warrenty on the SD-8a pack as you will be cutting clearance for the wires. Also, reversing the polairity of the fake bateries or incorectly wiring the unit will most likely result in the melting and or smoking of the SD-8a. While you will be attempting this mod at your own risk, I found the results were more than satisfing. In my opinion the cycling time and number of flashes per charge were equal/better than other packs in the $450+ range for a total cost of under $190.  (SD-8a $139.00, 7.2 volt 5000MAh battery 37.00, wire & connecters $10) A cheap Hong Kong version can be had for less than $50 including shipping reducing costs to the $100 range. ADDY http://www.dealextreme.com/details.dx/sku.14860


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## jstuedle (Oct 20, 2008)

I forgot to post this image of the SD pack closed and hooked up prior to inserting it in it's case. It shows how neat and clean the mod can be made.


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## Garbz (Oct 21, 2008)

Damn you and your miss-leading title. Here I was prepping to mod my flash for a higher guide number not a faster recycle time 

Very nice work indeed. Looks much more sturdy than many of the other dodgy battery mods I've seen.

Just be carefull that you don't fry the flash. 2seconds is not a lot of time to let a flash cool down.


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## Alpha (Oct 21, 2008)

Garbz said:


> Just be carefull that you don't fry the flash. 2seconds is not a lot of time to let a flash cool down.



haahahahahahahahahah.

Right.

If a $300 flash can't handle a 2sec recycle time then something is very wrong. In fact, I think something was already wrong. I don't use these things, but from what I can gather, the avg minimum recycle time is 6 seconds??????? And 2.7 w/a battery pack? That's insane! I get antsy if my flashes break a second and a half, and they put out twice as much power.


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## jstuedle (Oct 21, 2008)

I have used this rig for live bands and (gasp) one wedding. (I swore 28 years ago I would never shoot another wedding, but my grand daughter was a flower girl ) The SD-8a warns against more than 10 rapid shots in a row without a cool-down period. If this guide is followed I don't think there would be a problem. 10 full power manual flashes in about 18 seconds is more than I typically use anyway. This has been a good sturdy rig and should remain so as long as caution is taken.


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## pipeandwire (Mar 14, 2016)

nice article.. thanks for sharing. does anyone know what the third port on the sb800 is for if even being used? the last terminal on the left (while looking at the front) even seems shorter then the others. i checked cont between that terminal and the slide frame of it and its open. any ideas? im thinking of actually getting the same battery pack and plugging it in directly into the sb800. i dont have a sd-8a kit and looking to make due either with external battery or even getting an ac/dc adapter and plugging into a wall outlet. im going to be using it in a photo booth so 120v power will be there anyway for laptop and monitor.


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