An inverter takes the 12 volt Direct Current (DC) from the camper van house battery and turns it into 120 Volt Alternating Current (AC) household power. This allows you to use regular household power to run things like toaster ovens, microwaves or hair dryers.
A shore power charger takes 120 VAC from the campground power socket turns it into 12 Volt DC current to charge your house battery. So, when you camp in a campground that has plugins, you can charge up your house battery overnight.
A lot of camper vans include both an inverter and a charger as separate units in the van. They operate independently of each other just as described above.
Some manufacturers combine and inverter and a charger into a single unit – it is then called an inverter/charger.
So, you have a choice on your van of going with a separate inverter and charger, or with a combined inverter/charger. Here are some of the pros and cons for each approach:
- Combining the two units simplifies the mounting and wiring a bit
- The inverter/charger will automatically power the 120 VAC outlets in your van from the appropriate power source: If you are plugged into shore power, it will power your van AC outlets from the shore power and it will start charging your house battery vis its charger, and if you are not plugged into shore power, it power your van AC outlets from the house battery via its inverter.
- When you are on shore power, the AC neutral needs to be bonded to the ground in the campground power system and nowhere else. When you are on inverter power, the AC neutral needs to be bonded to the ground at the inverter, and only at the inverter. This is a safety requirement. Most inverter/chargers (including the one in our system) do this automatically.
- If either the inverter or the charger fails on an inverter/charger, you are probably going to have to replace the whole thing even though part of it is working fine.
- If you decide you need up the power of either the inverter or the charger, you will have to replace the whole unit even though one of the two might be fine.
- Some people think its cleaner to keep the two functions separate.
- It probably costs a little more to buy the combined unit rather than separate inverter and charger, and you will have more choices.
Separate Inverter and Charger
- Separate units that can each be replaced or upgraded independently.
- If one of the two units breaks, you don’t have to replace both.
- Probably a little cheaper, but do your shopping as it will depend on the units you pick,
- A bit more complicated to wire and mount the separate units
- You have to figure out how to handle the transfer of the point where the AC neutral is bonded to ground. The method we use on our system is just to keep the shore power AC outlets completely separate from the inverter AC outlets, so both can be bonded separately and no change of bonding point is needed, but some may not like having to use separate outlets. Another approach is to buy a commercial transfer switch.
Either of the two approaches works fine – just pick the one that appeals most to you.
My only caution would be to make sure that you handle the need to change the neutral to ground bonding point correctly. In the systems we describe, the inverter/charger version handles the transfer automatically, and in the version with a separate inverter and charger the problem is handled by just having separate AC outlets for when you are on shore power and when you are on inverter power – you just plug your appliance into the appropriate outlet.
In our set of electrical systems this is the one using and inverter/charger…
On my own van electric systems, I’ve always gone with an inverter/charger, but its always been a close decision.