[emeritus]

I got through dozens of blue Ever Ready U2's throughout the 1960's for my EL3585 tape recorder, and never had any leak. Prices were stable then, and a set of 6 cost 4/-. When the leakproof ones with predominantly white cases (SP2?) came out ( I think they may have been marked "sealed" rather than "leakproof") , they cost 5/-. I only got sets of them when I couldn't get the blue ones. They did leak! Both types lasted for about the 20 hours specified in the Philips instruction booklet when used for about an hour a day. As the recorder drew about 100mA, this works out at about 2Ah capacity. I usually had three sets on the go that I rotated to allow them to recover. I did try a set of the high power ones when they came out (HP2, orange case), but the recorder's speed regulator couldn't cope and ran too fast, whether because they produced a higher voltage or else their internal resistance was too low, so I never tried another set and can't comment on the effectiveness of their leakproofing. For comparison, in 1968 a packet of 20 Embassy cigarettes cost 4/6d and a gallon of petrol cost about the same.