Lithium battery technology is the power storage of the future. While the familiar AGM or gel RV batteries may only be discharged by 50 % to a maximum of 60 %, lithium batteries provide almost the entire amount of stored electricity. With the same dimensions and a much lower weight, almost twice the capacity is available.
Pay attention to the power output
If you are interested in purchasing a lithium battery, you should take a few things into consideration before buying. First and foremost, you should pay attention to the BMS (battery management system), which is usually installed on the inside. It is responsible for controlling and monitoring the entire system and also regulates the power output. If you want to operate an inverter with a LiFePO4 battery, you should make sure that the intended battery type is suitable for this before buying. Most batteries on the market – especially those offered at low prices – are far too weak and switch off.
Specially designed for motorhomes
Lithium batteries that are specially designed for motorhomes are not only designed for a higher power output. The individual manufacturers also build their batteries into the same battery boxes as all commercially available AGM or gel batteries. This means that they also fit into the original holder of the respective vehicles. These are then also equipped with the corresponding round terminals.
Fast charging process
Normal RV batteries (AGM/gel) have a very long charging time because the charging current must be reduced before they are fully charged. Lithium batteries, on the other hand, can be charged with high current until they are almost fully charged. This means that the charging process is completed much sooner. However, it should be clarified whether the charger installed in the vehicle and any existing solar controller are suitable for conversion to LiFePO4 batteries. Some battery manufacturers specify a charging voltage that must not be exceeded and the maximum charging time. In the best case, the individual charging options come with a LiFePO4 charging characteristic and can be converted accordingly.
Normal RV batteries in combination with LiFePO4
The combination of an AGM or gel battery with a lithium battery is interesting. The connection is controlled by a special battery computer and ensures that all the advantages of a lithium battery are made available. Only when it is almost completely discharged does the normal RV battery kick in. If the temperature is unfavourable for the lithium battery, it also takes over the supply. This system (PowerUnit) combines the best of both worlds and can be charged with any charger, regardless of how long the charging time is.
The LiFePO4 RV batteries are characterised by their high storage capacity, their low weight and their high cycle stability. Thanks to an intelligent battery management system (BMS), the batteries are internally monitored. The use of inverters is easily possible even at a higher output. Even the smallest version (MT Li 85) can be used with an inverter (e.g. MT 1200SI/SI-N) to power a Nespresso coffee machine or a hair dryer with up to 1200 W. From MT Li 105 onwards, you can use inverters for up to 1700 W. The batteries with 120 Ah and 180 Ah can easily be used with consumers (hair dryers, vacuum cleaners, coffee machines, etc.) that need up to 2000 W. Higher outputs are available with the versions MT Li 240 and MT Li 300.
The internal BMS not only provides high output power and monitors the battery. Several temperature sensors are also installed internally, which optimally charge the battery in every climate zone when using parallel charging devices (chargers, solar regulators, boosters, etc.). It is also possible to completely disconnect the battery from the power supply via an additional switch input. This is ideal when the vehicle is parked for a longer period of time or if you generally want to have a main switch function when leaving the vehicle. Of course, an auxiliary output is also available at the battery to keep an alarm system or important standby consumers working. In conjunction with a Pro-finder by Thitronik, it is possible to control the battery remotely via an app. The current voltage can also be read on the app and a special highlight is the alarm function. Triggered by the battery, an SMS is automatically sent to your mobile phone when the voltage of the RV battery reaches a critical undervoltage.
The battery casing of the MT Li 85 and the MT Li 105 was adjusted to standard dimensions. This makes it possible to install them in the existing standard bracket. Already installed cables can simply be set on top of it thanks to the round poles.
From battery size MT Li 120, the connection cables can be screwed on directly. However, it is also possible to attach adapters for round poles later on.