Conventional batteries are often used to power numerous household electronic devices. Sooner or later, the charge of this galvanic cell (even the advertised Duracell) ends and the device powered by it starts to fail at first, and then simply stops functioning. What to do with a battery that has exhausted (or seems to have exhausted) its resource? Quite numerous options are possible here.
1. Transferring to another device
A characteristic feature of a galvanic cell, which has almost completely exhausted its resource, is a sharp increase in internal resistance. Due to this, its output voltage drops, which affects the normal functioning of the powered device. You can “restore” the output voltage by swapping the battery to another device with significantly lower power consumption.
For example, batteries from a tonometer can switch to a tabletop or wall digital clock at the end of their service life. with LCD indicator, figure 1, where they can work normally up to six months, especially if not used alarm clock.
2. Reducing contact resistance
The second method can be considered as inverse to the first one: it is possible not to reduce the consumption current, but to reduce the resistance. The most critical in this situation is the contact resistance at the point of interaction between the battery poles and the contacts of the powered device. Due to the leakage of this area, after several months of operation, an oxide film with high resistance is formed under the influence of atmospheric oxygen. Destroy the film and reduce resistance can be cleaned with a fine sandpaper, in practice this procedure is often carried out with the sting of a slotted screwdriver.
For reliability, it is better to clean both contacts.
3. Battery as a tablet stylus
We usually use our finger to operate the touchscreen, but in some cases it is better to use stylus. Previously, this element was included in the package of the smartphone, now it has been abandoned. The functions of an improvised stylus can be taken over by a dead battery, Figure 2. With one finger you need to touch the negative terminal of the AAA or AA battery, after which it will become an excellent ersatz stylus for a capacitive touch screen.
This technique also works well in the cold.
4. Using AAA batteries instead of AA
Used AAA batteries can be used instead of AA cells to power low-power devices. The function of the makeshift adapter, Figure 3, which helps to install them in the socket, takes on the foil of the chocolate wrapper.
By the way, this same technique can be used for recharging.
5. Identifying a failed battery
Some devices require a supply voltage that exceeds the voltage of one cell. The problem is solved by connecting the batteries in series. Due to the different state of the elements, one of them can be discharged much faster, which, due to the growth of its internal resistance, affects the voltage of the entire chain.
A dead battery is identified with a conventional tester, after which it is replaced with a fresh one.
6. Partial charge recovery
The structural features of the battery and the chemical processes occurring during its operation lead to the fact that the initially available charge in it is far from being fully utilized. To achieve a deeper level, one can recall the old-fashioned way of “tapping”. This procedure itself should be carried out carefully so as to at least not deform the element body too much.
Conclusion
As you can see, the duration of using a dead battery can be significantly extended. How expedient it is instead of installing a new one - in each case it is necessary to decide separately.