Charging the battery “on the road”.
A good way to charge your battery charging while driving is by linking it to the starter battery of your bus, so that it charges while driving. Unfortunately, there is more to it than simply connecting the 2 batteries with a power cable.
First and foremost, it is important that you do not empty your starter battery in the evening while charging your laptop or the like. To avoid this, you must use a voltage sensitive relay. (VSR, Voltage Sensitive Relay)
- If the starter battery is charged by the alternator of the car (and the voltage is therefore high), the relay will open so that your 2nd battery is also charged. If the starter battery is no longer charged (lower voltage), the relay closes again. Simple but effective.
Such 'VSR' are cheap but don't do their job very well, so will AGM batteries but can be charged up to a maximum of 80% and there are no charging profiles available, which means that the life of your battery will be considerably shorter. With more modern cars it may even be that they do not work at all.
Modern cars (from euro5 engine) have a smart alternator, it switches on and off automatically while driving. Not handy if you also want to charge a 2nd battery. A VSR does not work here. You have a special battery-battery charger required. (DC-DC, B2B charger are alternative terms)
DC-DC chargers: The benefits
If your bus is suitable, a VSR as explained above are certainly sufficient, but we certainly recommend a DC-DC ( B2B, battery-battery) charger on. These are much kinder to your battery. By using a loading profile specifically intended for your battery, your battery is optimally charged, so your battery can be fully charged up to 100%. A DC-DC charger also works with more modern buses with a smart alternator.
Debie also has a DC-DC charger namely the Ctek D250SE which is listed below. This is a very high quality combi DC-DC charger with a built-in solar charger. It is a very simple device that is especially recommended for builders who have a 'set and forget' want the system, no bells or whistles, no bluetooth, install 1x and your battery will be charged automatically, both while driving and with solar panels.