Let the sunshine charge your battery.
Solar panels are the easiest solution to generate energy for your bus, especially when you don't drive much, this is very handy!
A solar charging system consists of 2 important parts. Namely, the solar charger and the solar panel yourself.
- solar charger
There are 2 main types of solar chargers: MPPT and PMW. MPPT is definitely recommended for use on the roof of a bus. These chargers are a bit more expensive, but they generate significantly more energy in less favorable conditions such as: cloudy weather. Victron MPPT solar chargers are the best in our opinion. The “Smartsolar range” also has a very good app for charting your yield.
Debie has a combi DC-DC charger with MPPT charge controller. You will find more information about this in the chapter “Charging the battery while driving”. - solar panel
When choosing between solar panels, it is important to know the difference between monocrystalline and polycrystalline solar panels. With Poly solar panels, the yield of the entire panel decreases when a part ends up in the shade. This is not the case with Mono solar panels and there is only loss of yield for the part of the panel that is in the shade. Not an unimportant detail with an ever-moving bus. adjust your charge controller to the voltage and ampere of your solar panels, which can be read in the specifications
Debie has 2 pieces of 110wp Monocrystalline solar panels. These were certainly not the most expensive on the market but work perfectly!
TIP: if you connect more panels together, this can be done in 2 different ways parallel or in series.
- In series :
plus pole of your first solar panel is linked to the minus pole of the next one. voltage is doubled, ampere stays the same. - parallel :
all plus poles are connected together and all minus poles are connected together. Voltage stays the same, ampere is doubled.
Calculate your solar system.
A good tool to calculate your required solar and battery can be found at Victron's website Here you can enter your daily consumption, your solar size, etc. and then you get an autonomy expressed in hours. This is of course not counting your solar panels, on the graph you can see in which months you would have sufficient capacity to fully recharge your battery every day.
Attention, you have to convert your barely hour (ah) of the battery and the consumption of all your devices (in ampere A) to kilowatts and kilowatt hours for the above tool. you can easily do these conversions via the following online calculation tools. The battery indicator of the Victron tool for Lithium batteries (100% can also be discharged). Therefore, enter the calculated useful percentage (in our case 75% because we have an AGM battery)
If we make this calculation for Debie's electrical system, we arrive at an autonomy of 62 hours. 2.5 days. In reality, however, we notice that we never have to charge Debie at the power grid in the summer due to our 220 watts of solar panels, which can be seen in the attached graph.
