DMX Power Catalog
Inverter/chargers and charge controllers
Do you really need both? For almost every PV and storage system, yes — and here is what each one actually does.
Two different jobs
What each one does
They are easy to confuse because both move power around a battery bank. The difference is direction: one converts energy both ways, the other only charges.
Inverter/charger
- Converts both ways. DC from the batteries into household AC for standard appliances, and AC back into DC to charge deep-cycle batteries.
- Takes more than one AC source. A hybrid unit can charge from a generator or the grid, so cloudy days off-grid and grid outages on-grid are both covered.
- Cannot charge from an array directly. It is not equipped to take the DC current a PV array produces, which is why a controller sits between them.
Charge controller
- Charges in one direction. Takes the power your solar modules generate into the batteries, and stops current draining back into the array at night.
- Matches array voltage to the bank. It regulates charging so the PV voltage suits the battery rather than damaging it.
- PWM or MPPT. MPPT captures far more of the available PV energy and allows more flexible panel and battery configurations. It is the better choice in most systems.
About
So do you need both?
Almost always, yes. MPPT controllers charge efficiently, but winter light and bad weather mean the sun alone cannot be relied on to fill a bank — and most loads want standard AC anyway. That is the inverter/charger. Meanwhile the inverter/charger cannot take PV current directly, so the controller has to be there to regulate it. Each covers what the other cannot.
The exceptions
- Controller only. Every load runs on DC, and your array reliably charges the bank all year.
- Grid interconnection without batteries. Look for an inverter designed and listed for interconnection.
- Storage or backup without PV. An inverter/charger alone connects the system.