Lithium-ion has changed the battery landscape for vehicle-based travellers. What do you need to know to invest in this new technology?
When we look at modern, life-shaping technology, rechargeable batteries must be one of the most important milestones we have reached. Cars and personal electronic devices wouldn’t have been possible without energy storage.
So, what’s in that mysterious black box and how is it evolving?
Let’s start at the beginning. The very first lead-acid battery was designed in 1859 by Gaston Plant. This was the first battery that could be recharged by running an electrical current back into it. At its most basic, a lead-based battery has a lead anode and lead cathode placed in a sulphuric acid bath. Lead-acid batteries are still used for energy storage in cars, motorcycles, and solar applications today, but because of the relatively low charge they hold compared to their weight – not to mention the harmful chemicals used in their construction – they are not practical for mobile devices. In 4×4 applications, where a secondary battery is required to provide continuous power to run fridges, lights, and other camping equipment, deep-cycle flooded lead-acid batteries have largely been replaced by longer-lasting and faster-charging ‘dry’ batteries. In these so-called AGM (Absorbent Glass Mat) batteries, the electrolyte is suspended in absorbent pads sandwiched between the lead plates. This type of battery, including those manufactured by Discover Energy, has proven over time to deliver far better results when compared to their flooded cousins. When designing a dual-battery system for camping or caravanning, the first requirement is to use devices that draw less energy – in other words, LED lights and fridges that use efficient, energysaving technologies. Next, one must be able to rapidly recharge the battery using a combination of lightweight solar panels and an efficient DC-DC charger for when on the move. When 220V is available, it is also imperative to top-up the battery using an intelligent mains-operated charger which can charge ALL types of battery.
Enertec’s Ultra Lithium-iron batteries (LiFePO4)
are the new wave of battery technology, with a
range of attributes that perfectly suits the off-grid
needs of vehicle-based travellers.
How does one size a charging system and batteries?
In respect of the battery capacity, this is worked out by taking the amount of power one’s devices need over 24 hours, looking at how many days one is going to be going away, and evaluating where one can recharge. A 100-Amp/hour battery is the most common choice, in terms of size, weight, and output. The 220V mains charger and 12V DC-DC charger should be specified at between 10% and 20% of your battery capacity. A bigger 140Ah lead-acid battery would provide more power for longer, but it will be larger, heavier, and require higher-output charging devices.
What about the new kid on the block – Lithium-iron?
There has been a lot of interest in the new generation of 12V Lithium-iron (LiFePO4) batteries now available for leisure market applications. Of course, these come with key advantages over lead-acid technology, and a few cautions. The first rechargeable Lithium batteries were only created in 1985 and commercialised in 1991. They use a complex mix of materials. The cathode is made up of lithium molecules trapped within other compounds, while the anode is usually graphite or a combination of carbon and other compounds, and copper substrates. The electrolyte solutions use a mix of lithium and other chemicals to offer different effects – more charge, higher energy density, more stability, or more resistance to overheating. Lithium batteries are widely used in today’s mobile devices because they can hold a high charge relative to their size and weight. In the case of a 12V vehicle application, a Lithium-iron battery weighing less than 12kg, for example, would have the output performance of a 200Ah lead-acid battery. Two more key attributes are that Lithium offers a rate of discharge that is stable for a relatively long time before it drops off rapidly, plus they can handle a high rate of discharge (in excess of 80%), without sustaining damage. Lead-acid batteries are rapidly destroyed when discharged to below 50% of capacity. A Lithium battery is able to accept a charge far more rapidly than lead and is able to operate at a partial state of charge and discharge for its entire life without any so-called ‘memory’ effect or the sulphation that plagues a leadacid battery under similar conditions. Crucially, a lithium battery has a charge life of about 6 000 cycles on average. This is very high in comparison to a flooded lead-acid battery with 300 cycles, or an AGM battery which can offer 1 000 to 3 000 cycles if properly maintained. Then there is the issue of cost. To put things into perspective, lead-acid is half the price of an AGM battery, with one-third of its lifespan, whereas Lithium-ion is four times as expensive but offers 10 times (or more) the lifespan and useable cycles, with no loss of capacity until very late in its life irrespective of whether it is partially charged and discharged.
The CTEK X5 – designed for automatic charging
of Lithium-iron (12V LiFePO4) batteries. A good
match for the D250SE DC-DC in-vehicle charger.
Is battery management technology all equal?
The biggest disadvantage of Lithiumion batteries is that they can be overcharged or overheated, which can cause the Lithium cells to combust, with potentially dangerous results. The solution to this is to add an advanced and intelligent Battery Management System which prevents overcharging, over-discharging, or thermal runaway by monitoring the cells and shutting down the battery if safe parameters are exceeded. Unfortunately, many Lithium batteries being sold today have inadequate management systems, poor quality cells, and no manufacturing standards. Not only do they have a short lifespan, but the purchase of these ‘cheap’ batteries comes with a risk to life and property. By contrast, instead of jumping into this new market sector, Enertec spent several years researching, charging, One can use a smaller Lithium battery to complement the charging capacities of the D250SE when speccing a vehicle-based system discharging, and destruction-testing many lithium cells and battery management systems before settling on the Enertec-branded Ultra Lithium-iron batteries on offer today for off-road and home use in a safe, affordable package. The batteries that Enertec supply today are high-capacity, long cyclelife lithium packs that have advanced battery management systems which are Bluetooth enabled and can be monitored by a simple free-to-download mobile phone App.
Do Lithium batteries need specific chargers? Just as your 4×4 needs the right fuel and maintenance, it is necessary to feed the battery correctly in the form of Voltage and Amperage levels in an intelligent algorithm that supplies the battery what it needs for optimum performance. CTEK charge systems of Sweden is a leading manufacturer of professional workshop and home-use chargers that are a staple of the South African off-road experience. For 220V mains charging, it is imperative to choose the correct intelligent charger for a Lithium-iron battery and here CTEK’s Lithium X5 covers the bases. CTEK also supplies dedicated invehicle battery charging systems, in the form of the intelligent D250 dualbattery charging system that integrates alternator and solar panels to charge your leisure battery more efficiently than a solenoid-based system. If you drive a vehicle with a smart alternator or intend to build a dual-battery system using an AGM or Lithium battery, CTEK has you covered with the new D250SE DC-DC charger. When it comes to the world’s finest batteries and charging systems, Enertec and CTEK have a partnership that brings together a team of experts who have a time-proven track record. They are ready with the technology and expertise to meet the challenges of today’s leisure lifestyle.
One can use a smaller Lithium battery to
complement the charging capacities of the
D250SE when speccing a vehicle-based system.