Computer Batteries

You may think the only role for a battery in a computer is to keep your laptop running without access to mains electricity (unless you know abut the little batteries on motherboards too...) but you'd be wrong.

Once upon a time — after relays and valves but before IC's — computers were built not with transistor only logic but with diode-transistor logic (DTL) and RAM was not semiconductor based at all but built from little tiny coils of copper wire (actually knitted or sewn by knitters/seamstresses).

And once upon a time you couldn't start a computer like a Ferranti Argus 400 (a core store module from which is shown above if its battery was flat (photo by adewale_oshineye).

Yes, I know this from first hand experience with an obsolete Argus 400 being disposed of by Tioxide in Hartlepool.

We actually had to jump-start it... with jump leads and a car battery. So... progress of sorts.