The most difficult part is to open the original battery. Corrosion usually holds everything well together. Simply follow these step-by-step instructions:



In theory, it should simply screw off, but.. you will see. Probably corrosion has risen it's ugly head, and there is no way to apply much force without special tools. You have to hold the battery's knurled outer ring, and find yourself a tool to attach at the two tiny holes (yellow arrows in the picture) in the top plate, and then unscrew counterclockwise. Of course, you will say, but reassuring to know when you're pulling with all forces and nothing moves! The tool I use here is made to open watches, I can only reommend to get something similar. You need a lot of force to open the case, without a suited tool it's nearly impossible. Of course, the image above is just for illustrative purposes. Do not use such a tool without some rag or leather to protect the outer knurled ring, or it will be damaged for no reason. One battery I recelled was hopeless, I litterally cracked it open with a screwdriver I inserted and twisted by the center hole, hitting it with a hammer. The top plate finally gave up and popped out, the plate being heavily deformed but the thread stil intact. Again with a hammer I "ironed" it as much as possible, and screwed it back on. Not elegant, but it worked.


As you can see, there are six round cells within the case. Probably some weird yellowish-white crystals have developed and are now pouring on your workplace. Bah. Most likely very toxic, better to keep away from pets, children, don't taste it, and wash your hands after touching it! But keep the ring-shaped contacts and insulation plastics. Only get rid of the cells, you'll need everything else later, especially the 3.6V contact. Don't forget to take it out before throwing away the cells. On the picture, you can also see the chrome chipping off. Believe it or not, these chrome chips work their way into all gears and moving parts of the camera, I've seen it myself. Rest assured that every ebay Beaulieu needs service to keep working.



I recelled my first battery with six "Lady" 11mm*28mm sized NiMH cells, which fit nicely in the batterry case. Solder them together and connect it to the appropriate contacts of the case. I used a copper plate for the center contact, and re-used the original contact "ring". It's a good idea to keep the original contacts, in case you get the original cells later. It's important to make sure that the contacts are soldered good, and that the batterys don't move around. Best is to glue them together, and use a shrinking tube. The soldering should in no way be abused to keep the cells in place! The battery almost looks like before, only the different +7.2V center contact indicates that you've been messing around.
Pros: Cells are easy to find Cons: lot of work, does not look really professional. If you work sloppy, the contacts may become unreliable.
For a reference how to arrange and solder the batteries, have a look at this pdf diagram provided by Pedro, a member of the 8mm filmshooting community, and hosted on a site from Bertrand Chauvel, also a member of the forum. See link to Bert's external battery article below.
You probably could make a fortune with the information I'm giving you here ;-) Just have a look how much new batteries cost. Truth is, it's cheap and very very easy to do. The difficult part is to get the cells, they are not very common, but still are manufactured. Until recently, they were available at Conrad - but unfortunately they have taken them out of their portfolio! I regret that I didn't buy at least 100 cells, but it's to late now. When I find a new source, I'll update the information here.
I keep the info here, so you have a reference and know what to look for, and if enough people keep inquiring, Conrad may add it to the portfolio again. Conrad is based in germany as you may have guessed, but they ship worldwide. These cells are triple cells, meaning that one cell replaces three original cells. You need two to recell a 4008 battery.

They fit exactly, and the result obviously looks just perfect. Pros: done in less than 5 minutes, rock solid, and better than the original battery. It's so easy and obvious to do, that I did not even bother to take a picture of the steps involved. It's just reassembling in reverse order ;o) Cons: None that I'm aware of.
Check them out:
Pedro's DIY battery as described in the 8mm forum:
Bertrand Chauvel describes his DIY external battery in this article, also in the 8mm forum
Michael Nyberg also describes how to build battery packs, together with more info on the Beaulieus