In 2017, a new RV concept suddenly appeared in the RV exhibition in the second half of the year – “no external power connection”. This concept means that the RV uses a large number of lithium batteries for power storage, and uses solar energy, car generators (12V) for power supply, and finally uses an inverter to convert the stored 12V DC into 220V AC for use in the RV, thereby getting rid of the need for external connections to the RV. electricity dependence. Is this seemingly beautiful RV power solution really reliable?
With the extensive publicity and exposure of RVs in recent years, more and more people know RVs, accept RVs, and use RVs. People can’t help exclaiming that the “RV Era” is coming. At the same time, users’ little knowledge of RV knowledge also makes RV life full of uncertainty.
Among the many vague knowledge, the lack of knowledge of RV power system is the most important. Because the lack of knowledge about the power system of the RV will not only cause troubles to the life of the RV, but also cause considerable danger. Here is a simple analysis of the RV power system. I believe that after a simple understanding of the RV power system, everyone will have their own judgment on whether the “no external power connection” of the RV mentioned above is reasonable.
clear distinction
The power system of the RV includes three parts: 12V DC (hereinafter referred to as “12V”), 220V AC (hereinafter referred to as “220V”) and RV driving system (12V).
1. 12V DC
12V DC is the common power and reserve power supply of RVs. Many RVs in China directly convert most of the electrical appliances in the car to “12V”.
produce
There are two main charging modes: car generator (12V) and external power 220V (vehicle 220V generator is also classified as external power), with solar energy and wind power as auxiliary charging.
store
Electric energy is stored in the living battery of the RV, which is generally a deep-cycle high-capacity battery or battery pack. Deep-cycle lead-acid batteries are often used in foreign RVs, which can be deeply discharged and recharged without too much impact on battery life. In China, due to the low understanding of RVs, some RVs will choose the same start-stop battery as the car or a lithium battery with poor stability.
use
In the charging state, the caravan is given priority to use the charging power supply; in the non-charging state, the output power of the battery is used to supply the caravan’s daily electricity, such as refrigerators, hot water (including gas hot water), lighting, water pumps, entertainment systems, USB ports, etc. . Domestic RVs also use an inverter to convert the 12V power supply into 220V for the 220V electrical appliances in the RV, which is rare in foreign RVs.
2. 220V AC
220V AC also plays a big role in the RV as household electricity. In addition to being one of the best charging methods for RVs, 220V electricity is generally used as an energy source for parking air conditioners, microwave ovens and other energy-intensive electrical appliances.
produce
Use for mains access at camp or at home, or generator supply outdoors. As mentioned above, domestic RVs will use inverters to convert the 12V power in the RV battery into 220V power to supply high-power electrical appliances in the RV. Due to the low storage capacity, continuous output cannot be achieved.
store
none. The 220V electric energy cannot be directly stored in the RV, and can only be stored in a disguised form by storing 12V electricity or generator energy (gasoline, diesel, gas, etc.).
use
It can be directly used by air conditioners, microwave ovens, refrigerators, 220V sockets, etc., and it can also charge 12V living batteries at the same time.
3. RV driving system
The electric energy of the RV driving system refers to the system that generates, stores and uses the RV during driving.
A self-propelled RV is the same as a car, so I won’t go into details here. It should be noted that the driving power system of a self-propelled RV is relatively independent from the power system of the RV. In addition to the lighting system outside the car, it only undertakes the functions of part of the lighting in the car, driving air conditioning and charging.
Compared with the self-propelled RV, the driving system of the trailer-type RV is simpler. The trailer-type RV is only connected to the tractor through the wiring harness, and there are only two functions of external lighting and charging.
Staggered
Although the circuit of the RV is distinct in composition, in practice there are many places where they are interleaved with each other. For example, the refrigerator in an American RV is a typical case. This kind of refrigerator is usually powered by three energy sources: gas, 220V, and 12V. In the cooling effect, gas > 220V > 12V, and 12V is still needed for auxiliary when using gas as energy to drive.
At the same time, because the RV industry in our country is still in its infancy, there are many imported RVs and domestic self-designed models, so even the RVs with conventional voltages are different. For example, the charging voltage and living voltage of RVs imported from the United States and Japan are 110V, 60Hz, while in my country it is 220V, 50Hz. Generally, the conventional voltage of vehicles is 12V, and some models use 24V voltage as the conventional power supply in the vehicle because they choose the chassis of large commercial vehicles for modification.
back to the question
After a brief understanding of the RV power system, return to the question at the beginning of the article. Is this “no external power supply” really reliable in actual use? The first is storage. Changing one battery into two, changing 80AH to 200AH will result in an increase in the weight of the RV and a change in the counterweight of the RV. In addition, the stability of lithium batteries needs to be further discussed. The second is to give up the supply of external electricity, and only choose solar energy, car generator (12V) and so on for charging. Solar energy is greatly affected by external forces such as latitude, weather, and terrain, and can only be used as an alternative to other charging modes in actual use. Car alternators may seem reliable, but they are not. The RV is often parked in one place for several days, and the engine does not start at all to talk about generating electricity. The last is the inverter system of the RV. Due to the limitation of storage capacity, even with a large number of batteries, it is still difficult to meet the 220V power required by normal life.
epilogue
We are constantly getting to know the RV while using the RV, and many people will put forward some opinions based on their own understanding. As a comprehensive product of travel and outdoors, the RV has many similarities with home life, but there are also quite a few differences. This makes us often see only one aspect of the caravan like a blind man. This requires everyone to consider whether it is reasonable and safe when putting forward their own opinions on the caravan, and finally get out of the fuzzy era of caravan power.
