Hello,
A similar theme about a solar installation on the T&B 320: T@B 320 Modifikationen - Tipps und Beratung erbeten
I've just bought a T&B 400 2010. It came with a 12v battery system with battery and charger from 230V. I wanted to be "Autark" so I wanted to have solar panels on the roof. You only loose about 10% solar energy during the day if you have the panels flat on the roof compared to have them pointed to the South. I have glued with Sikaflex two 50W Sunbeam flexible panels above the kitchen. I have made a hole in the roof for the cables and sealed it with Sikaflex. I have made the panel connections in the kitchen cabinet. Sunbeam recommends parallell connection of panels but I've connected them in series with bypass diodes. The disadvantage with series connection is that they will be more sensitive to shading but they will give more power when there is less light and no shading. As the voltage is higher (the double) there is less losses in the cabling that can have a smaller area also.
I have a MPPT-regulator with Bluetooth connection to an app in my mobile telephone where I can check the status and also control the settings. I have installed a battery bank with two identical 95Ah AGM batteries. I have installed the battery bank under the double bed. I have also installed the MPPT controller there as I wanted short cables to the batteries. The old electric central is in the wardrobe. I may have wanted to have the solar contoller in the wardrobe also but it wasn't possible to install the solar panels above the wardrobe because of antennas and ventilation outlets on the roof.
I have substituted all lamps to LED. Instead of the fluorescent lamps in the toilet there are LED-stripes. There where no 12V sockets so I have installed sockets to be able to charge mobile phones, computers etc.. I have installed a small electric central with fuses near the solar controller. It's very important to put fuses on all cables and devices to avoid overload of cables and risks for fire! I have made the installation myself as I have professional knowledge and experience of electrical installations.
Update: The T&B 400 is rather "back heavy". I have now a battery bank with 190Ah capacity that weighs about 50kg. That's about 30kg more than a single 70Ah battery. As the battery bank is under the rear bed this means that the load balance of the caravan has changed. I do always use a scale to check the balance. I want to have about 50kg on the ball on the car. It's ideal to have bicycles on the towbar or transport the tent inside at the front of the caravan. It also depends if you have one or two gas containers and how heavy they are. Is it water in the fresh water tank? A possibility is to use the waste tank as a ballast if nothing else helps. I send a picture where you can see the solar panels. Roof_TAB.JPG
The nominal capacity from the panels is 100W. As they are serial coupled they will give an output also during cloudy days and mornings and evenings. Most of the daytime the voltage is around 40V. Of course the MPPT-controller transforms this to battery voltage. The output from the panels should be balanced with the capacity of the batteries. Practice will tell if this is correct.
If someone has questions I'm willing to answer them and maybe also publish pictures of the installation. I do understand German.
Best regards,
Per