At present, the mainstream of RV is 12V, so why is it 12V? The reason is that at present, some DC loads in domestic RVs are 12V, such as light strips, DC air conditioners and so on. There is also driving charging, because the current chassis of the B-type or C-type RV has a built-in driving battery charger of 12V. In this way, a dual battery isolator can be installed to charge the living battery, so most of the 12V power systems are more convenient. (The so-called lithium batteries currently refer to lithium iron phosphate batteries, with a nominal voltage of 12.8V and a maximum voltage of 14.8V, but usually for safety, the charging voltage of the charger is generally 14.6V.)
At present, there are some truck chassis on the market, like SITRAK, their battery system is 24V. For a 24V system, you can convert the lithium battery according to 12.8V, and the full voltage is 29.6V. Compared with the 12V system, the current of 24V is half smaller, the cables used can also be nearly half smaller, the safety performance will be higher, and the wiring will be easier. But the disadvantage is that if there are some DC loads in your RV that are 12V, you need to use a step-down device, but the safety and reliability of one more component will decrease, but there is no big problem using a regular factory.
Now let’s talk about this 48V system. In fact, in the European vehicle standard, that is, the E-Mark certification of electronic equipment that can be installed on the vehicle. The R10 standard is that the vehicle battery system cannot exceed 36V, because the RV does not have a grounding system. There are also some cars that hang an iron chain under the car in order to solve this grounding problem, but it is still not safe enough. Therefore, the vehicle system is a common negative electrode. What is a common negative electrode? That is, the negative poles of all DC products are connected to the frame. When taking power for various devices, you only need to take a DC positive pole, and the negative pole can be connected to the nearby frame.
If your vehicle system is a 12V system and your battery system is 48V, if the installation is not professional and the isolation is not well done, it is very easy to cause problems. This is why we often encounter 48V systems in the main reason for the unstable use of the RV, the irregular burning of equipment, and the burning of electricity. The current mainstream voltage in Europe and the United States is still 12V.
How many batteries should I have in my RV?
As for what you just said, how big of a battery do you want to use depends on how long you want your device to last while parked? The nominal capacity of 12.8V lithium battery 100AH is 1.28 kWh, and if it is fully charged with a 14.8V, it is 1.48 kWh. Many riders here also have a misunderstanding. They think that my 400AH is 4 kWh, but it is not. According to the nominal voltage, 12.8V400=5.12 kWh. If it is fully charged, it needs 14.8V400AH=5.92 kWh.
Regarding the conversion of this number of kilowatt-hours, KWH, W=V*A, so, from a professional point of view, what is the capacity of the battery in WH, not AH, 5120WH=5.12KWH=5.12 kWh.
This is the way of battery capacity. How much electricity does a device of that size need to use? Let’s take an example, a kettle is 1800W, I want to burn it for an hour, it is 1800W*1H=1800WH=1.8KWH=1.8 kWh, and the power consumption of a household air conditioner 1.5HP (horse) is 750W, running 750W for one hour *1H=0.75KWH=0.75 kWh, of course, when your temperature reaches, the compressor will stop, so the power loss will become smaller, if you want to ask how much battery to use, then you need to calculate your usual electricity consumption The amount of battery, and then decide how much battery to use, the choice of a large battery also depends on the configuration of your charging device.
The 400W solar panel configured by a rider basically generates about 1.5 kWh of electricity a day. If you configure 5 kWh of electricity and only have solar panels, it will take about 3 days. Of course, there are also many riders who have installed dual battery isolators. If it is 100A, then you can charge about 1.3 kWh for one hour of driving. There are also AC chargers. If you use a 100A charger, it is about the same.