The via / pad configuration on this batch of boards allows for 3s1p as well as 1s3p configurations. Of course it allows for the extrapolations you’d expect (6s1p, 9s1p, 2s3p, 3s3p, etc). It does not allow for any neat-o configurations such as 4s2p in a 9-cell carrier. 4s2p in a 9-cell carrier (3D) can be done using jumper wires and some PCBs with different via configurations.
There are several clearance issues in this revision.
Also I didn’t even think about the giant Maglite tail spring. It’s large enough to swallow all 3 screwheads and short the 3 outer pads. Ummm… oops?
Thanks Rod911. I’m not sure about my plans. The price for a 6s1p would probably be in line with battery adapters from fivemega or mdocod. It seems like a vicious cycle for Maglite builds, with parts availability getting lower all the time. Mdocod and fivemega are both completely out of the 3AA game, and fivemega is just selling off remaining stock of 4AA adapters. I think I could reasonably expect to sell my adapters as kits and let enthusiasts handle their own assembly. Hopefully that would work well for international shipping as well since these would pack flat into a padded envelope. I’ve still got a ways to go on this and the 4xAA design.
I would be happy with a 3*AA in parallel as these should substitute well for D sized cells, right? They’d be used for a Rayovac 300 lumen lantern I’ve got. The extra AA should give it that little bit more extra run time (6000mAh vs 4000mAh) that my current 2*AA adaptors provide.
Werner, I don’t have the dimensions here with me. It is very small. Almost exactly 1in on it’s longest dimension. The benefit is that 3xAA fits into an unbored Maglite tube! Also, positive and negative don’t end up at the same end of the adapter (on the 4x note that a fly wire is used to move the positive pole to the correct place). For some driverless incandescent builds 3/6/9 cells might make more sense than 4/8/12 etc, I don’t know a lot about that stuff. The most important thing is fitting into an unbored mag.
I did use OSH Park and ENIG (gold) finish is standard there.
Thanks for the complements. I’ve done a lot of new work to the 4xAA board, but have not had any more prototypes made. Unfortunately the design has become much less beautiful - all in the quest for minimizing resistance. I’ll probably continue working on the 3xAA design right now since I don’t have any bored Maglites or a lathe yet.
Rod911, I almost missed your comment. Yes, a 1s3p configuration would replace a single D-cell. What is the battery configuration in your Rayovac lantern? eg how many cells are there, and are they physically arranged in a straight line or do they sit side by side? Note that my adapter does NOT capture the cells. It relies on the maglite tube to hold the cells in place. If the Rayovac has lots of space around the batteries, this could be a problem.
I'm in for a 12AA-4D carrier kit when they're ready
Will your final 4AA-xD design have a max diameter that is the same or smaller than four Eneloops stacked side-by-side? I ask because I have a 2D MagLED from 2011 that can fit 8 Eneloops with no friction.
Slim Pickens, the initial 4xAA boards were 32mm. Four Eneloops should be a good bit bigger than that: about 33-34mm. The current revision of the 4AA boards measures a measly 29mm! Based on what I’ve done with the 3AA adapters I’ll probably do another complete overhaul of the 4AA design before prototyping it again.
OK, new prototypes ordered. Learning from my own mistake and standing on mdocod’s shoulders a bit, I allocated about 14.5mm diameter for each cell. I did some on-screen mockups and I see about 1mm-1.5mm of total play when using very small cells in a big Maglite tube. That should definitely be small enough to prevent contact problems or anything, and hopefully small enough to prevent rattle. With snug enough springs I think it’ll be fine!
