CR20xx cell stack holder
 

Apropos of nothing in particular but it might be of interest to others :)

Whilst pondering on making a 16.5v low power requirement supply for a voltage reference I'd built a while back, I've found that the inside of a Multicore solder reel is a perfect fit for the CR20xx range of coin cells - see pic.

I'm [low current]-ly considering how to implement a contact arrangement & will post again in a [non-short] while ;)

Guy

Re: CR20xx cell stack holder
 

Here's my best endeavours ...

I've used 5 x CR2025's having a total stack thickness of 12.2mm* with connecting straps formed from a bit of 1.2mm² FT&E earth wire; I pre-drilled 4 x 1mm holes then "bodged" them out with a tapered implement. Assembly needed care - but it seems to have been a success :) Now for some careful trimming of the remainder of the Multicore tube.

Guy

* For 5 x CR2032s, it's 15.65mm - as measured with a digital caliper (yes, I did indeed put some 0.05 plastic film between the stack / caliper jaws ... then deducted 0.1mm :) )

Re: CR20xx cell stack holder
 

What a good idea, I like the repurposing, how have you arranged to keep the cells under compression?

T

Re: CR20xx cell stack holder
 

It all came down to careful measurement/positioning of the 4 holes ... having fitted one copper strap, I added the stack making sure they were 'parallel' to the diametral plane of the tube - if you see what I mean! - then whilst pushing down on the stack at the other end, I inserted the other strap. The 1.2mm² FT&E wire has sufficient stiffness to give a good contact across the faces of the cells at each end as well as maintaining sufficient compression throughout the stack to minimise the risk of iffy contact between adjacent cells.

It's nice to be able to make this up out of odds & sods (my garage is a shrine to the concept of re-purposing!) and I'll post some pics once I've added the LT1236 10.000V voltage reference chip (on a bit of Veroboard) plus an on-off switch and some proper 'test point' style sockets.

The box I'll be using was originally associated with an SES-Astra 'Point 'n' Play' two-way satellite broadband alignment meter - I had several of them left over from my rural broadband business when I closed it down in 2016 :)

Guy

Re: CR20xx cell stack holder
 

My handy 10.00(0) volt reference gizmo is now finished ;D
"What fun!" *
Guy

* (as the late great Sir Terry Wogan used to say in that hysterically funny series 'Janet & John')

Re: CR20xx cell stack holder
 

I see that a new line in CPC's latest catalogue is nickel-plated steel battery spring contacts. 10 for about £1 for AA & A, 10 for about £2 for C & D cells, VAT extra. Could be useful for this sort of thing as well as repairing springs damaged by leaking alkalines. I shall include some in my next order.