Does anyone make a good spacer "dummy cell"?

[electromage]

I want to make a 4xD size battery pack using 3x LiFePO4 "D" cells, and a spacer on the end. I want the spacer to contain a charging port, protection circuit, and a basic charge indicator.

I think a good quality spacer will be required, as it should be as strong, or stronger than a real cell. It also needs to be hollow to fit the electronics. From what I've seen, they look like they're typically low quality plastic, with a wire running from one end to the other. I want something that will be able to take some shock if I have to break something with my flashlight.

 

[electromage]

I'll take that as a "no"

 

[Mr Happy]

You could buy some of the low capacity D size NiMH cells, like these for instance, and gut them. I can't say for sure in every case, but often these big cells are constructed as a plastic shell around a smaller inner cell. With care and ingenuity, you might get a rigid hollow cell casing to work with.