The following article gives information on where to find your battery and how to jumpstart it
As your truck battery is located on the under-floor area inside the cab area, if your truck battery runs low and will not start, there are jump-start positions under the bonnet. It is much easier to jump start from under the bonnet as opposed to accessing from the under-floor area.
Please refer to the video below on where and how to pop the bonnet and you will see where to attach your jumper leads.
Please note:
These new engines still have a small draw on the battery when parked up, so if you are not going to use your motorhome for a month or more, please take it for a drive or start the engine in your driveway to keep things ticking over. If your motorhome is going into storage, it may pay to lock the battery up to a trickle charger.