Looking for a 3-port bi-directional DC-DC converter

DIY
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1

Hi everyone,

I’m putting together a 3-port power management architecture and could use some advice on the best approach or off-the-shelf components from victron.

Here are my system constraints:

  • Architecture: 3-port system (Input, Battery, Load).

  • Input Power: I can use either 20-30V DC or 230V AC mains. I’m open to whichever yields a better/easier solution.

  • Battery: 24V Li-ion NMC pack (70Ah) with an internal BMS. It requires a 29.4V top-off. It has CAN comms, but if I use a “dumb” charger without CAN, I need to limit the charge current to 15A max.

  • Load: 24V at 500W continuous (~21A).

  • FBehavior: I need seamless, zero-delay switching. The battery should charge when input power is active, and instantly take over the 500W load when the input dies.

Does anyone have recommendations for a preferibly a single-box solution that handles max 15A lithium charging alongside a 21A load?

Thanks in advance for the input!

2

So you need a multiplus inverter or skyla charger that can deliver 36A. So you have the Multi 24/1600/40, which can give up to 40A, which will give you a cheaper solution than the charger only, plus more control over the charger.