What can a lead-acid battery destroy?

Basic knowledge of starter batteries

Begin! Regardless of whether it is a lawn tractor, wheel loader or excavator, they all have an electric start. A fully charged battery must be available so that the electric starter is fully functional.

Mostly come as starter batteries Lead-acid batteries with a nominal voltage of 12 volts. They consist of six cells with 2 volts each. In each cell there is one positive, one negative plate and an acid-permeable separating film (rubber or plastic). Depending on which medium is between the plates, a distinction is made between wet, gel and fleece batteries. Depending on the polarity, the hard lead plates are coated with either sponge lead (minus) or lead dioxide (plus). 38 percent sulfuric acid is used as the electrolyte, as this degree of dilution has a high conductivity but does not attack the plate material.

Handling a starter battery

A low-maintenance gel battery for lawn tractors.

It starts with the right charger. Old Transformer chargers with a linear characteristic can generate charge peaks of up to 20 volts and charge them with excessive currents. That would be special with Gel batteries harmful. When charging with too high a current (depending on type, for example gel battery via one and wet battery above 5 amps) and / or too high a voltage (above 14.4 volts), the gas voltage in the battery increases and lead oxide parts are blown off the positive plate. These then lead to a plate short circuit. Therefore always charge with voltage and current limits (maximum 2.4 volts / cell).

In addition, the Transformer charging technology the ability to switch to the trickle charge state when the standard voltage is reached (usually 14.4 volts). The new generation of chargers automatically recognize which type of battery they are connected to and which internal battery errors or defects are present.

If the battery hangs on the charger for a long time, it comes thanks to "Iron circuit" to a constant partial discharge and partial charge, and then increased sulfation occurs, which is associated with an increasing loss of capacity. The service life decreases.

A lead-acid battery must therefore not hang on the charger for a long period of time. When not in use, the battery should be fully charged, frost-free (an uncharged battery freezes at -7 ° C, a fully charged battery can withstand temperatures above -30 ° C), but in a cool and dark place. Then charge it about once a month and before using it again. This is necessary because this type of battery is constantly self-discharging. This phenomenon is higher at summer temperatures than in winter.

But also the Check the fluid level is to be done regularly. Since acid is not lost if there is no leak in the battery, there is no need to refill this liquid. In contrast, water disappears in the form of water vapor. Therefore, only ever top up with distilled water. As convenient as maintenance-free batteries are, they have the decisive disadvantage that no water is topped up and the acid density cannot be measured.

In addition, many alternators do not manage to charge this energy storage device to 100 percent, and for this purpose they have to be connected to the mains for up to 24 hours with a special charger. This should always be considered before buying a new battery. New batteries must be fully charged before installation. Otherwise a sulphate layer will prematurely form on the panels.

Battery damage

Deep discharge (below 11.8 volts) as the main cause of failure is fatal to any battery as it destroys the positive and negative plates. Because the lead sulfate builds up on the plates and breaks through the separating film. A total write-off due to a short-circuit is the result.

This can happen especially in winter. Because at -10 ° C a starter battery only has 60 percent of the power it has at +25 ° C. At 0 ° C, the power loss is already 20 percent. Also Housing breaks are not uncommon. Since the standard installation promotes this type of damage, it is advisable to put a buffer layer around the battery housing using an old rubber mat before installation. This is particularly advantageous in winter service operations, as the risk of breakage in the battery housing increases as the temperature drops. If the battery is mounted free-standing on the vehicle, it is advisable to enclose it in order to protect it against impacts.

Especially with older batteries it can lead to internal short circuit come because so much lead sludge has built up over the years. This builds up on the negatively charged plate and causes this damage.

The connection contacts of the battery are made of lead. This is a soft and chemically and thermally sensitive metal. The smaller the battery, the more delicate these components are. If too much force is applied or a shock load is applied, these break off very quickly. Besides, it comes to quickly corrosion , especially at the positive pole, which can also totally destroy it. Therefore, the good, old pole grease should be applied regularly. Because that not only protects the battery, but also the cable connections.

Finally, a word about disposal . Regardless of whether it is a lead-acid battery or a lithium-ion battery, disposal must be carried out by special companies. The easiest way to do this is to use the energy storage system as a source of supply because they have entered into corresponding cooperation agreements.