Roll-your-own Nikon F5 battery pack!!

To those who think that this is a waste of time and prefer shelling
out big bucks for Energizer Lithium’s, hit the ‘back’ button and
forget you ever saw this.


For those who don’t mind getting their hands dirty, and are capable of making a circuit board and doing a bit of research in order to have a perfectly good battery pack and charger for an F5…well, a wordy welcome to you.

If this whole page seems a little rough, well, sorry.  I'm not a real web-head...what you see here is actually the kind of page that I, as a surfer, prefer.  All the content in one big continuous drawl that just goes on and on until you hit the bottom of the page.  I personally can't stand pages that dole out the info in small sections, forcing you to go page after page after page...  

If you're a Nikonian, sorry for the visual shock factor...coming from Nikonians to this page is like suddenly driving from the nice part of town into skid row.  But hey, I assume you're here for the meat and not the trimmins' so here ya go...


First off, you can really bork your camera if you do this wrong, so don’t mess it up or you’ll be dishing out some $$ to get your F5 un-screwed-up by Nikon repair.   I think that this would be a real drag, so I was careful when I made mine.  Now, I’m an actual qualified electronics tech, so this really isn’t that big of a deal of a project for me.   If you’ve built a few things already from scratch, you’ll probably find this one pretty straightforward.   If you’ve never done anything like this, then forget it.

Also, this isn’t really a step by step how to…I will assume you’re resourceful enough to find the little bits that are missing and know what tools to use etc.   This is just to inform whoever reads this (mainly fellow Nikonians) that it is possible to do this, and that you don’t have to spend the big bucks for a Nikon pack.  In case the first line (wayyy up at the top of the page) applies to you, but you’re still reading, you should know that just because one decides to afford an F5 doesn’t mean one should want to afford the Nikon pack or Lithiums .   I have an F5 because it’s good value (for ME), and the Nikon packs just aren’t (for ME) and I’m not a pro so I didn't go for  the Nikon stuff.   I’d also make my own remote cord if the connector wasn’t proprietary, but that’s another story.

Of course, if I was a pro photographer then I would not do this…I’d just buy a few packs and a charger, smile about it and deduct it come tax time.   I’m sure the Nikon packs are excellent (though overpriced) and that the charger is pretty good too.  But, since I’m good at electronics, can’t justify the expense and CAN actually do it (regardless of what other Nikonians may think)…I did it and am happy with the result.  Again, I'm not a pro...schmoe maybe...but not pro.

Allow me to pontificate for a moment:
Now, some people seem to believe that there is some kind of voodoo going on inside the camera, and start talking all sorts of trash about current and electrons and e=mc^2 and how the camera knows blah blah blah and that the camera is going to explode if you try anything slightly different from what the book says.  The simple story is that rechargeables make the camera wind faster because their internal resistance is lower, and can deliver more power (power = volts * current) to the camera.  When the power demand of the camera is high, alkaline batteries run out of steam and can't deliver; rechargeables can.  You can't hurt an F5 as long as you are delivering 12 DC volts to it, and not exceeding by any large amount (I'd say no more that 13 volts total).   (That's a CLEAN 12 volts...ie, not from one of those crummy wall-wart adapters...their power output is full of ripple)  OK...so the 12 volts has to be from a battery, or from a super-clean AC adapter.  There is no magic going on in there (it's a CAMERA, not a plasma ball, ouija board or mini Teletubbie)....it's all ohm's law, and nothing more.  Of course, making your own pack would probably void the warranty, but what you see here on this page does not modify the standard battery holder in any way...it's totally reversible, and I can go back to alkalines or lithiums if I want to at any time...(but I really don't want to).  Some people really need to get over this 'expensive camera mystique' thing and realize that it's just a box with some motors and mirrors and circuits...it's dumber than the average computer and Nikon sells their cameras by the pound.  (It is the heaviest ...isn't it?)

Now, it's a wonderful, beautiful, powerful sexy camera; and I just love it....but it's just a CAMERA!  People in the F5 forum talk as if it's magical or something...it's not.

Maybe I'm not as romantic about it because I got mine third-hand and a little rough around the edges.  It's liberating to have a scratched-up camera...you don't priss about it all of the time and just worry about taking pictures with it (and, well, building battery packs for it).  Hmmm...I guess you think about lenses too; but that's another story, to be written while looking over the Nikkor lenses brochure.   "hmm...how much for that 600mm AF-S again?....or how about that 28mm f1.4"

I suppose if you really wanted something long-lasting you could make yourself a battery belt with 9 rechargeable D cells.  It would probably go 30 or 40 rolls, and, since it's a belt, it would be good in cold weather too...  (Here in Northern Ontario, you think about these kinds of things!)  But I'll pass on that because I like the cold about as much as the batteries do, which isn't all that much....  But to close out the idea, I think it would work well with ultra-soft microphone cable to connect the battery belt to the body...

OK...on to the battery pack project...

What you need:

- 1987 edition of the ARRL Handbook (a handbook for radio amateurs) and all of the parts for the battery charger project
- 9 rechargeable batteries (I used NiCad…you could probably use NiMh)  My thinking was that, since I only shoot 4 or 5 rolls per month, I could kill and recharge the pack once a month, thus giving the batteries thorough workouts, which is what these things like best.   NiMH probably has too much capacity for MY use but I might go that route at some point, if I find myself shooting more.  Now, when you're looking at these different types of batteries, keep in mind that the maH rating is only an indicator of the CAPACITY of the battery (like the GALLONS spec of your gas tank).  This in no way indicates how that battery will act under the actual stress of actual use...that is determined by the internal composition of the battery itself and boils down to its' internal resistance.  As far as I understand it, NiMh and NiCad are about the same in terms of internal resistance, and therefore perform about the same.  (Check this out by reading the recycle times for an SB28 flash with different batteries).  I could be way wrong on this, so I will leave lots of room for that (It's been known to happen....me being wrong, that is).

Sorry...I didn't mean to take us off track there about batteries....I used NiCads because they suited my needs and the price was right $6 CDN for 4 at the Home Depot versus $20 for 4 NiMh.  Another factor in that decision: I don't have and wasn't able to find any info about charging NiMh batteries...it's not rocket science, but I didn't want to guess at how to do it.  If I find some good info, I may change horses and go NiMh, if only for the higher resistance to memory effects....

1. Making the 2-cell pack

First off, you need to make the battery pack hold 9 batteries.   This is well documented here and I’m not going to go into it in any great detail.  The short of it is that I’d been thinking about how to do this with an MB16 battery pack for a Nikon F80 camera, but gave up because there is really no place to put the extra cell unless you mangle the MB16 and I didn’t like that idea too much because the silly thing is $100.  But the F5 is different…it physically has enough space for a 9th cell right there in the body cavity.  My F80 is now a dust collector BTW, because the F5 makes an F80/MB16 combo seem like it was made by Fisher Price...but that's another story for another day...

OK, back to the pack: Instead of buying the 9th cell adapter, I wired 2 batteries in series with some wire and some solder.  This is a bit risky if you’ve never done it before….basically you need a pretty hot iron and a good hand…solder a jumper from the negative side of the battery that will go in the holder over to the positive of the one that will sit on the side.   Next, cover the soldered area on the one that will stay in the holder.   Then, take a short piece of solder tab from a headphone jack and solder it on the ‘side’ battery, and make sure it extends over to the insulated area of the ‘holder’ battery.   Don't use too much heat, or bad things might happen to both you and the battery.
 
Battery Pack Battery Pack


This all will take some exprerimenting…basically you want these 2 batteries to be in series, and make it so they can sit side-by-side in the holder…  You have to leave a few millimeters between them so that the 9th battery can sit outside the plastic holder clips.

Making this 2-pack is critical because if it’s messed up, you risk shorting out a cell, which will make it go into meltdown, and if it’s inside your F5 when that happens you're gonna have a bad day…don’t say that you were not sufficiently warned about that.

Now, the '9th cell adapter' that's for sale is a nifty little thing...and makes the above step un-necessary, which is good because it's kind of a funky thing to do anyway.  I was just too pig-headed to cough up the $$ to buy one of those...If it had been cheaper I may have bought it, just to save me the trouble of the above steps.

2. Read the article, build the charger…

The article (in the ARRL handbook) is quite good, and the book includes a template for your circuit board.  I tried out this new iron-on masking material (that you create by feeding through a laser printer), but I don’t think it was that good…results were OK, but only the 2nd board was usable…the first was ruined because the mask lifted off while the board was etching.   Also tried ammonium perslulfate etchant for the first time, so that may be part of why I lost 1 board.  If I was really ambitions, I could have come up with a circuit of my own design...but hey...why re-invent the wheel...this one seemed pretty good and I'm not so sure I could have come up with something better without spending a lot of time designing and testing...not worth it...

Here are a few shots from my little project…

Board  
This is the first of the masked boards, the second one awaiting masking with the new material.

Etching  
Etching the two boards.  
I thought the heat from my monitor would help things along…it's a 21" NEC
Multisync, and gets pretty hot!


Board  
This is the completed, etched board.  A little rough looking, but fully functional.   

 Board
This is the partially completed board, component side.

3. Test and adjust

The article in ARRL handbook tells you how to set it up…adjusting the voltage to 1.44 volts per cell etc.  This is critical, since if you don’t charge to batteries to just the right voltage, you will not get all of their capacity…this is a weird pack, of course, because it’s 9 cells, and must be adjusted to 12.96 volts (I did 13.05, actually…).  'Course, if the pack wasn't a bizzarro voltage, I wouldn't have had to build a charger....  Connecting to the Nikon battery holder is easy...just use alligator clips...of course, make sure you've got the polarity right...  It's actually not all that obvious when you look at the holder...I used the meter to make sure....

Pack
Initial charging of the pack…woo-hoo !...no smoke!
One meter monitoring current, the other monitoring voltage.
Note the fancy self-adhesive bonding strips used to fasten the 9th battery beside the pack…
(I took these with my F80, in case you were wondering...)

Discharge
Discharging the pack, to give it another go…that's 2 8-ohm power resistors in series...This is just to make
sure that the pack is discharged to about .8
volts per cell…note the voltmeter to make sure.  I plan on
doing this every
month or so, just to keep those memory-loving NiCads in line...
(I scanned this from a negative...and didn't clean up the scratches...don't worry...it's not your eyeballs!)
(But the bottom of my F5 is a little battle-worn...)


4. Take pictures, and have fun!

Total Cost: $15 CDN for the batteries, and about $20 worth of parts and material.   Thinking about ordering another AA holder to make a 2nd pack.
I did this during break time/lunch time at work, so I don’t know the actual time…maybe 4-5 hours total.  YMMV.

I don’t know if I’m getting 8FPS instead of 7.4…and I don’t really care because I haven’t used this fast mode yet, and if I ever do, 7.4 is probably fast enough.

The rewind speed seems much faster, probably 4 secs like Nikon claims for the NiMH pack…nice…convenient…but again, I don’t care.

I built the pack to avoid feeding the camera batteries all of the time…this is better for the environment, and allows me to easily top up the pack before I need it.

My next project?...I'm going to build my own AF-S 17-35mm f2.8 lens!