HP41 Battery idea Lipo

[Diego Diaz]

Hi all,

@Freeclimber
As Bob said, welcome to the community.

Clearly a coincidence, the general idea is pretty straight forward and I know for sure I'm not the only one working on this.

Good luck with your project!

@rprosperi

Bob, I really appreciate your confidence in my success! ;-)

Let's see how long it takes for this idea to become a real thing.

@MeindertKuipers

I'm not planning to go the 3D housing path for now, just naked PCB's.

Look forward to see your implementation (your design ideas are always inspiring).

From the three main problems, inherent to these type of power packs, that you've pointed out; I think I've sorted out the first two: USB-C type connectors can easily fit in the standard charging port of the 41; and by all means only protected batteries are considered for this project.

Working on a solution for the third: the BAT indicator. It requires some sort of "emulation" of the discharge curve of the alkalines, and I think it can be done by tweaking a bit the DC-DC converter with some 'amplified negative feedback loop' (just an idea for now), and yes I know it may sound kinda contradictory since it's a stet-"up" converter... :-D

Ordered the parts, let's see how it works.

All he best from the (heavily rainy nowadays) Caribbean.

Diego.