Batteries - what everyone should know 2

In the last material, we focused on the types of cells and the main differences between them. Today it's time for some useful information on the selection, charging and proper operation.

The beginning of all considerations regarding the selection of a battery for installation is the consumption balance and analysis of receivers. Planning of consumption is the key to possible modifications, it is also worth diagnosing potential sources of savings.

An example is a comprehensive "switch" to economical LED lighting instead of halogen lamps that are still common. The next step is to create a list of receivers along with their electricity needs and working time. If you have a problem here - it is worth writing down your own habits for a few days to define your needs on the basis of such a "protocol". If you are a fan of winter caravanning, it is also worth taking into account the clearly greater demand for energy. If you add a battery, remember that the type, capacity and age should be as close as possible to the first one.

Markings precisely identify the product. For example, the G 80 on the label indicates a gel battery with a capacity of 80 Ah.

Proper charging

Each of the available technologies (lead-acid, gel, AGM or lithium-ion) has specific advantages and disadvantages. Even the best battery will do little if we do not adjust the charging. The power source for the on-board battery can be a charger, solar, alternator or an alternative power source (eg EFOY). Nevertheless, it is recommended to charge the batteries for at least 12 h from the 230V mains at least once every four weeks. If the charging current is too weak and we move often, it is worth considering investing in a device supporting the charging process - the so-called "Booster".

To charge a lead-acid battery, it is best to use a charger (rectifier) with appropriate characteristics (preferably with a temperature sensor). We assume that the higher the temperature, the lower the charging current.

Modern chargers have modulated operating characteristics and can be adapted to charge various types of cells. It is extremely important not to exceed the maximum voltage - for lead-acid and gel batteries it is 14.4 V, while for AGM - 14.8 V). For advanced and expensive lithium cell batteries, chargers with BUS technology are recommended, allowing two-way communication between the cells and the rectifier. This allows you to extend the service life of the batteries. The general rule is - the charger power should be at least 10% of the battery capacity. The AGM and lithium models can take more.

The maximum charging current is also an important parameter. It depends on him how quickly we charge the battery. The regeneration of lithium batteries takes several hours, while lead-acid batteries often need a minimum of 12 hours. The prerequisite in each case is that the charger has the correct characteristics. In many cases, the usual 16/18 amp models may not be enough. Even if sellers often advertise the trouble-free replacement of "old" technology batteries with LiFePO4 (and vice versa), it is necessary to check the compatibility of these components. In extreme cases, we may damage or not use the full potential of the batteries, and also void the warranty.

Charging in frost as well - in temperatures below zero degrees can damage the lithium battery. Appropriate temperature sensors regulating charging are sometimes located outside and sometimes inside the cells (better solution). The energy reservoir should always be in the heated space. If our vehicle is used in winter, the lithium batteries should be charged only after reaching the appropriate ambient temperature. Each type of battery is more or less temperature dependent. The capacity of the LiFePO4 battery is significantly reduced at temperatures below zero and above 45 degrees Celsius. Similar relationships can also be seen in the case of lead-acid batteries.

Service life

How you care, so you do - rarely any folk wisdom would more accurately describe the dependence of caring for a battery on its durability. And so, in the case of lead-acid batteries, remember to recharge them regularly, otherwise their capacity may decrease drastically over time. Before wintering, it is best to connect the battery to the charger for 1-2 cycles and disconnect the clamps.

The service life, i.e. the number of possible cycles, is closely correlated with the number of times the battery is discharged. There is also talk of the so-called Depth of Discharge. The same battery in AGM technology, for example, will achieve 400 cycles at 80% DoD, while at 50% it will be 600 cycles. However, these values are pure theory, as the batteries are used differently in practice, and each cycle is accompanied by different conditions and temperatures. Therefore, not all manufacturers provide the number of cycles for lead-acid batteries with a nominal service life of approximately 4-7 years.

The situation is completely different in the case of LiFePO4 batteries. Although the technology is relatively new and there are no long-term test results, it is assumed that these products are extremely durable (nominally 3000 cycles) and practically maintenance-free. They feel best when they are partially discharged (50-70% capacity). Of course, these links will also be subject to "aging". This is best demonstrated by the batteries of our mobile devices.

Summary

To sum up - users of small and medium motorhomes operating with a small undemanding consumers will basically be able to deal with a gel or AGM battery. However, if someone prefers caravanning "in the wild" and wishes more independence, and even reaches for a dryer or a coffee machine and uses a voltage converter, he should definitely be interested in lithium technology and the benefits of modern LiFePO4 solutions. We would love to hear your observations and experiences with mobile power - we invite you to the discussion!