Victron DC/DC Charger

[JunieBird]

Hi, with our C-288, there are port & starboard Orion-TR Smart 12-12-30 DC/DC isolated chargers. My understanding is that the Yamaha F250 outboards will create up to 70A from each alternator. Are the DC/DC chargers undersized and thus not maximizing charge capacity? Thank you

 

[S. Todd]

Creating up to 70A from the alternators (assuming that is the specification) does not reflect the amount that is generated at less than maximum RPM and could be considerably less for most of your cruising time.

 

[watson1987]

Standard alternators will burn up if you attempt to drive them to max amperage for long periods of time.

You need to get into large format alternators with charge controllers (temperature adjustment) in order to push things up even close to the stated maximum, even still it's just the theoretical maximum under ideal conditions. General rule of thumb is 50-70% of rated capacity.

Given your alternator is also producing power to drive the engine itself (ECU, injectors, fuel pumps, ignition) your 30amp charger is perfectly right sized for dumping the remaining power to your domestic lithium bank.

 

[Mike and Sarah]

We have 2 50 amp Kisae dc-dc chargers on our S310 with twin Yamaha 300. You can set make charge from 5-50 amps. Ours are set to 50 but never see more that 42 amps from them. So I assume that is the max the alt can safely put out after supplying the engine with power to run its normal systems. We can get that 42 amps from 800 rpm to wot. When at lower rpm the chargers cycle between charging engine battery and house. When around 1200 rpm most of the time the charger is at 42 amps going into the house. With just a very small amount of time going to engine battery.