Deep Cycle AGM Batteries
Lithium car batteries
Lithium is the lightest of the solid elements and is the most popular types of rechargeable batteries. The very first lithium batteries were not rechargeable.
It has one of the best energy/weight ratios. The self-discharge rate is also low so when it is not in use it does not lose its charge very quickly.
In fact, lithium batteries were initially unstable and unsafe and around charging times they were particularly unsafe making them unsuitable for the market. This is when they discovered that lithium-ion was the way to go.
Being twice the energy density of standard nickel-cadmium batteries they make an excellent car battery. Lithium-ion batteries do not require much maintenance and on top of this advantage, they do not require memory or scheduling cycling.
Traditionally Lithium Batteries have been used only for Hybrids but they can be used in normal petrol engine cars and especially in 4WD where a second battery is used to power camping utilities such as camping fridges and power inverters. In this case, a normal lead-acid battery is used for the first battery and the Lithium Battery is used for the camping or alternate use requirement. Where you are travelling for long periods you need a second battery so as not to rely on your main car battery essential for starting the engine.
So to be clear the advantages of a Lithium Battery is their weight, they are much lighter than lead-acid batteries. They also cope with the charge and discharge cycles a lot better than the traditional lead-acid batteries. However, there are a few disadvantages which should be mentioned. Compared with a lead-acid battery a Lithium Battery’ output will drop a lot faster when the temperature decreases. They do require proper charging and can have cell failure if not charged as manufacturers recommendations. They are also quite expensive in comparison. A well-designed Lithium Batteries however do not cause these problems such as the EnerDrive Lithium Batteries.
Deep Cycle AGM battery
An alternative to the Lithium Battery is a Deep Cycle AGM battery which is a lead-acid battery but with several differences. AGM is short for Absorbent Glass Material.
So the battery has 6 cells of around 2 volts each making 12 in total. The positive and negative lead oxide plates react with the sulfuric acid electrolyte producing electrons and this electrolyte is suspended by the sponge-like glass fibre maintaining an even distribution with the lead oxide plates.
Although the AGM battery is sensitive to over or undercharging it is basically sealed and needs no maintenance so you can not spill any of the contents. They are mostly shockproof and do not corrode. They also are more efficient at discharging and recharging. It is claimed they have higher starting power. In general, they do cost more.
Another advantage is they typically last sometimes more than twice the regular lead-acid battery. When supplying a twin battery for a camper or 4WD we usually provide and install the DC105-12 Deep Cycle AGM Battery as the second utility battery.
What is the Deep Cycle part of the name mean? Traditional car batteries were not designed for continuous draining and recharge as they are used to start the engine and are then used for small power uses while the engine is running and the battery is continually being recharged. However, if you are using the second battery system as a power supply for your camping fridge you will not have the car running at the time and there will be a constant drain on the battery. A deep cycle battery will have thicker plates which help it cope with constant charging and recharging. The thicker the plates the longer it will last.
Deep Cycle batteries are designed to provide a steady amount of current over a long period of time. Deep-cycle batteries can be repeatedly discharged and recharged without causing damage or shortening their life.