Leaky batteries

[DrStrangelove]

I remember buying Halfords cells that were leaking in the packaging with 5 or more years left on the date.

In my last employment the Instrument Store held a shedload of Thandar kit which had C cells within.

The Duracell were toast, every single one, leak city.

The Varta cells on the other hand still had enough oooomf to turn the instrument on and very few if any had leaked.

The storage conditions were fairly dire since the room was permanently at about 90 deg F or more due to all the heating pipes that went through it (it didn't need a radiator for this very reason).

The Varta AAs that I bought in packs of 100 were very good.

Sadly they were discontinued by CPC and replaced with some chinese wonders, which leaked vigorously even when unused.

[Mike Watterson]

Cool/cold but not frozen dramatically extends shelf life of any kind of battery.

I forgot to mention that my 12c each bulk Chinese CR2032 and CR2025 are as good or better than the €2.50 each ones in Tesco.

Recently I converted all my electret mic from AA cell to using 2x Alkaline N cell (aka Lady, E90, LR1) as that gives better S/N and more than x4 dynamic range. They were a crazy price in Tesco. I had some about 6 years old still good (some cheap brand from a local shop), but the local shops now only have LR1 in a multipack with other cells, so not good value. I got Camelion "Plus Alkaline" packs of 5 from Germany last year and even including shipping less than 1/2 Tesco price for Energizer or Duracell.

Usually there is enough space in an electret mic to cut one end of the battery holder and move it back a bit.

No series capacitor either. The load resistor is on the output in series with batteries to FET (+ to FET, - to load resistor). The resistance and (electrochemical) noise of the cells is sufficiently low. The operational life is still massive and shelf life no different.