Inverter

[Martin]

I am a new owner of a 2015 R27 and have a couple of questions
1: Can you have the inverter on whilst running the engine
2:Can the battery charger be on at the same time as the motor and whilst the inverter is on or just with shore power

 

[Martin610]

You can run the inverter while the engine is on. DO NOT run battery charger and inverter at same time. This assumes separate charger and inverter. Enjoy the boat!

 

[Brian98133]

There is no need to have the battery charger 'on' whilst the engine is running because the alternator from the engine is charging the batteries.

 

[JeffRad54]

You can run the inverter while the engine is on. DO NOT run battery charger and inverter at same time. This assumes separate charger and inverter. Enjoy the boat!

Why not run the inverter and charger at the same time?

Thanks,
Jeff Radwill

 

[Red Raven]

The inverter draws current from the 12v DC batteries to create 120VAC AC. The charger draws current from 120V AC to create battery charge at 12vdc+. Having them both on creates a loop that would draw current from the inverter (and thus the batteries) only to recharge the same batteries you are drawing the current from (batteries cannot charge themselves!) With losses in both the inverter and charger this would result in a quick drain of your battery bank and likely blow the fuses or trip the breaker in your inverter (or damage it!).

The above assumes that shore power is not on, selected, or not available. If it were why would the inverter be on? There is no need to turn on the inverter if shore power is available.

On many of the boat models this scenario is impossible as the battery charger circuit is on a shore power supplied AC circuit separate from the inverter supplied AC circuit. Also many of the boats have a combined battery charger/inverter where only one function can be on at a time.

On some of the older boats (including mine) the inverter is independent from the charger and the full AC panel (including the battery charger) is powered when the the rotary switch is set to inverter. On these boats the scenario above is entirely possible but should be carefully avoided by the operator so as not to drain the house batteries quickly or potentially damage the inverter.

Curt

 

[BB marine]

Why not run the inverter and charger at the same time?

The inverter is powered from the batteries. The charger is powered from shore power or a generator. Using the inverter to power the battery charger is counter productive. A ProMariner battery charger 20 amp uses approximately 8 amps 120V to power it. It would take approximately 88 DC amps @12 V to power the inverter to produce the 8 amps @ 120V needed to power the charger.

 

[JeffRad54]

Why not run the inverter and charger at the same time?

The inverter is powered from the batteries. The charger is powered from shore power or a generator. Using the inverter to power the battery charger is counter productive. A ProMariner battery charger 20 amp uses approximately 8 amps 120V to power it. It would take approximately 88 DC amps @12 V to power the inverter to produce the 8 amps @ 120V needed to power the charger.

Thanks so much for the obvious, now that you've said it. That probably explains why I get the low voltage alarm at 5 AM at anchor! I'll add that excellent bit of information to my RT Owner's Manual.

 

[Chimo]

I use the inverter very sparingly. As has been pointed out, it puts a heavy load on the house batteries. I'm usually only reheating some food or making tea in the microwave when I am at anchor and in this case I always start the engine before turning on the inverter. I suspect you have the Volvo D3 engine which has a rated alternator output of 150 A. I haven't yet found a speed/output curve but at idle you are going to get a lot less than that but still enough to power your microwave. As you turn on the microwave you will hear the load come on the engine.

One small thought, if you do a search here you will find that several of us have tied in the thruster battery to the house batteries since the thruster is usually not used when at anchor or on a mooring buoy. That gives you an extra 50% house battery capacity. I have done this with a switched connection and if you're interested you can see a picture in the modifications folder of our album.

 

[JeffRad54]

...
One small thought, if you do a search here you will find that several of us have tied in the thruster battery to the house batteries since the thruster is usually not used when at anchor or on a mooring buoy. That gives you an extra 50% house battery capacity. I have done this with a switched connection and if you're interested you can see a picture in the modifications folder of our album.

That's not really a good idea. House batteries are deep cycle (rated in AmpHours) while the thruster battery is a starting type battery (rated in CCA). It's poor practice to co-mingle different types of batteries in the same bank.

 

[Chimo]

...
One small thought, if you do a search here you will find that several of us have tied in the thruster battery to the house batteries since the thruster is usually not used when at anchor or on a mooring buoy. That gives you an extra 50% house battery capacity. I have done this with a switched connection and if you're interested you can see a picture in the modifications folder of our album.

That's not really a good idea. House batteries are deep cycle (rated in AmpHours) while the thruster battery is a starting type battery (rated in CCA). It's poor practice to co-mingle different types of batteries in the same bank.

Maybe different on different boats but the factory delivery on our 2017 RT 25SC was 4 identical Universal AGMs. I do agree about not mixing different types. It’s been discussed as have many things viewtopic.php?f=2&t=15905&p=104529&hilit=Thruster+house+batteries+combined#p104529