EDIT: D Cell carrier for the OPUS BT-C3100 - FINISHED, pics in OP

I have been thinking about this ever since I got my BT-C3100. Great charger, charges so many different cell chemistrys and sizes. But not “D” cells.
Today I got started making one. What I have done so far is the “messy” part, cutting and sanding. That I always prefer to do outdoors, on the largest cleared work surface I have, the driveway. :wink:

The B3100 will accommodate “C” cells, but only at the 2 outer cradles. “C” cells are approximately 1” in diameter, I was fortunate to have an old broom handle that size. The smaller dowels came from the inside of an old window shade. I cut them to the same length of an 18650 cell. I figure that will give about the right amount of tension when they are inserted into the carriers.

I figure there is little to describe from here as the pics tell most of the story.








I need 4 of these “D” cell holders, I only have one, it came from my local Radio Shack and cost $1.49. They also sell a 4 cell version for $3 but it is already configured for series operation, what I need is 4 separate hookups. I took a look at it and decided that it would be too hard to reconfigure it.

Now I need a platform on top of the dowels to tie this all together. nothing too thick. I’ll use material from an old lid from a cat food bucket. Our cat seems to be concerned with what I am planning, but not to worry, I have other empties in the garage. :slight_smile:

It took a lot of cuts to get what I wanted, but I got it.

All that is left to do is get the other 3 holders and mount them on the board, and wire them up. I need to attach the leads to buttons on each side of the dowels.

I have stopped for today because now that I have seen it through to this point, I am wondering if the combinded tension of trying to compress all 4 springs at the same time will make it difficult to insert this. I am now leaning towards splitting it in 2 pieces. Also that would have the advantage of only using 1 of them, exposing the other 2 slots for other uses. I would not necessarily need to charge 4 “D” cells every time.

EDIT:
I decided to reduce the length of the dowels to the length of an AA cell to reduce the tension needed to insert the carriers. By doing this I was able to put all 4 carriers on one board.

Here are is my stash of “D” and “C” cells, the reason I need to charge 4 at a time. It will take some time to recondition them all, as they are quite old and the process on the BT-C1000 takes some time.

Cool! Unique. I like creative solutions. I thought for sure this thread would involve some steal of a deal from Home Depot, so I was a little disappointed.

-Garry

http://www.amazon.com/Battery-Adapter-Charge-BT-C2000-Chargers/dp/B00CR6TAJ2

I knew of those and the price, but each one takes up 2 slots.
It is a nice easy way to go, the way I usually choose, but not this time. I want the option to charge up to 4 at a time.

Sorry Garry, not even the dowels came from HD. They wanted $3.75 each for 3’ of the 2 sizes I needed.
That brings up a good point, the cost of materials for modding. It is so easy to spend way too much on components for a mod. Those carriers from Radio Shack are $1.49 each and for what they are, that is way too much. I checked EBay and all the vendors there want about the same. I’ll end up spending $6.00 total on this and not a penny more. 2 of those adapters that Gj pointed out cost only $6.74 each. If I didn’t want to charge 4 at a time, I would definitely have gone that way.
If it makes you feel any better, I DID get a great deal on the chop saw and the belt sander. They both came from HD and I got killer deals on each of them, way back when. :wink:

Finished and I updated the OP with new pics.

Very nice. It looks like some sort of flying space ship.

What does the wiring look like? A picture of the underside of the board would be good. I assume each carrier is wired to an individual slot? Are the wires just placed between the dowel and the contacts? Or did some soldering take place?

Those of us interested in this don’t want to get into any trouble. :slight_smile:

I just finished reading a PM from Paramount Pictures, they are trying to figure out how the design for the Romulan cargo ships in the sequel to “Into Darkness” was leaked!
It must be that one of “Us” here on BLF is a Paramount exec. :smiley:

Do you think the Romulan ship runs on the older Di-hydride crystals rather than the newer Di-Lithium crystals? :slight_smile:

The carrier is busy at work right now reconditioning some cells, (the process really does work!) So I took some pics in place. I’m sure the wiring is just what anyone would expect, 4 channels with each cell holder wired to a screw in the end of each dowel. I used some stainless steel sheet metal screws screwed into ends of the pre-drilled dowels. I did not have any terminal lugs so I just wrapped the bare wire around the screw before I tightened them. Later when I get the lugs I will soldier the wires to them. If I never get to that, I’m pretty sure that what I have done on a temporary basis will still be good enough.
BTW, the reason the outer 2 dowels have a wider OD is because the outer slots on the charger are wider to accommodate the 2 - 26650’s and “C” cells that it can charge in stock form.

Very clever.
Excellent mod.

“WTH do people use D cells for these days?” I thought.
Then I remembered MagLites…

Nice mod dchomak
.
I’ve just a few D cells left. I use them in an old radio recorder I really like. This thing was produced as quality was a point of planning and production, not like this shiny & smelly “easy breaker” these days (Predetermined breaking points to max profit).
But if the cells will die, I’ll use 2x AA to D cell adapter.

Believe it or not, back in 1965 I had a GE AM transistor radio that took 4 C cells. There was no AC option. I invested in 4 - RayoVac NiCads to run it. I don’t remember what they cost, but in 1965 dollars it was a lot!
I do remember that the radio cost $20, I am guessing the batteries cost me a little less. It was always comforting to not to be concerned with running the batteries down while listening to the radio.
I just remembered that the “C” cells were a beautiful metallic blue……

The charger I used was one of those back then that also claimed to be able to recharge ordinary Carbon-Zinc cells. What it really did though was just warm them up a little to make the chemicals inside a little more reactive so that they could work awhile longer. Not the safest setup, that’s for sure.

Thanks,

Yes I have Maglites, quite a few actually.

I hear ya. Mine if from the 80’s and includes AC connection. But this thing is heavy, just sits in the Garage. Only issue with this is that the volume knob needs to be cleaned every now an then (sliding contact or so).

My grandfather had a compact transistor radio from the 50’s or 60’s with a leather sleeve running on a 9V battery. Worked 40-ish years w/o an issue.
Recycled in the 2000’s because … for a new one (or a transistor gave up)? I don’t know exactly why.

Since torches (flashlights) have become led and consequently run on AA or even AA, D cells have become a little less used. They still have plenty of uses in things like radios especially power hungry digital models. Older and larger analogue models still run on Ds and Cs where their greater capacity usually run more powerfull amps and larger and bassier speakers.

I have a few of the old Soviet radios (actually made in Riga, Latvia) which run on 6 D cells. Made in the 1960’s they have no FM but do boast AM (long and medium wave) and 6 SW bands. To change the batteries you undo 2 screws to get the back off and then 4 more to undo the 2 battery compartments! Combined with a large turret wave changer these are not very portable. Just google Spidola and you’ll get to see what I mean.

I have many other radios that run on C’s and D’s and that’s why I still need this capability in any charger that I buy.

In the mid 80’s I got this Panasonic boombox. Sounds real nice. A distinguishing feature is that the speakers can detach and be connected with wires. While they are attached they connect by means of a plug and socket system.
This AM-FM-Cassette Radio will run off straight AC or and external 12V DC supply. It will also run off 8 - “D” cells.

Nice solution dchomak. Thanks for sharing.

  • How did you affix the carriers to the plastic sheet (and the plastic sheet to the dowels)?
  • What did you use for contacts on the dowels?