In message , Stefan
writes
In article ,
says...
100AH is its total capacity. Normal rule of thumb is to only
discharge it down to 50%. So, you have 50AH of useful
capacity.

The advice for NiCad batteries for mobiles etc. is that it is good for
them to go through complete discharge-recharge cycles.

Only applies where a critical cut-off voltage is involved for the
equipment. Otherwise "memory" is an urban myth

Anyone able to
explain why lead/acid batteries are different - if indeed they are?

Tend to have steeper discharge curves and be used in non voltage
critical applications

--
Keith Lewis