Posts Tagged ‘batteries’

@TheGreenParty recycling dry cell batteries

May 12, 2017

Most people buy dry cell batteries for a specific device and then chuck them when they begin to fail.

I’d like to suggest a little experimentation, using a multimeter.

These devices are quite cheap nowadays and my digital version was about £6.

The graph shows how the voltage of these batteries drops with use.  Basically the central carbon electrode gets blocked off by gases and effectively insulated.

If this problem didn’t exist then the batteries would work at maximum voltage until all the Zinc casing was eaten away but it doesn’t. This is why they’re recyclable.

This graph shows a typical voltage characteristic for a battery, although most can be 1.6 volts when new and some can last longer than the average. In my opinion the cost of the better ones is usually too high and it’s more efficient to buy two average ones.

What I noticed was that my wifi mouse ate up batteries but the batteries still registered about 1.45 Volts on my multimeter. Placed in my wifi headphones they began to give problems whilst reading about 1.35 Volts. Transferred to my wife’s “candles” they worked well until about 1.2 Volts, when only the red LED was giving light. These would still work the remote controls for some considerable time until the Volts dropped to about 1.1 volts.

These figures aren’t rigorously proven but merely serve to give an idea of how to minimise cost and waste.

It’s worth checking out your own needs, if you’re as penny-pinching as me.

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dead batteries

July 26, 2011

Dead batteries.
When batteries die, their voltage drops and consequently the Current that they can push through a circuit. I notice that bulbs require the biggest current and so the P.D. drops quickly, dimming the bulb. These bulbs can be used for a while in audio devices such as MP3 players. Even when these now appear dead, they still seem to work in remote controls, which require only microAmps.
In the old days when dry cell batteries were sealed at the top with tar, we’d puncture the tar and set the batteries in front of the fire. I later learned that this caused the gases that had built up around the central electrode (called polarisation) to expand and escape. As these gases had been preventing the internal flow of current, the process renewed the batteries activity for a while, until the gases built up again. I often wonder whether it would be possible to make extremely long lasting batteries by enabling some way of releasing the gases, without the Ammonium Chloride paste leaking also.