House Battery charging question

SeaEsta-12

Petty Officer 2nd Class
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May 25, 2012
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Hello all you helpful boaters.......I have a question for you, and hope you can help me with an answer.

I have a house bank of two 6V batteries hooked up to give me 12 volts. The on board charger is a 40A.
I am planning on spending a couple days on the hook at Catalina Island.
If I fully charge my batteries before leaving, and then hook up my portable EM650 Honda Generator which outputs 550VA to my shore power cord with an adapter, will that generate enough power to keep my house batteries topped off for the two days, or would it be best to just use my generator to plug in appliances that I need to use?
My inverter is a 2000W Xantrex and if I use certain larger appliances, it will deplete my house bank fairly quick to below 12V and it will shut off for safety reasons.

Thanks for the help everyone!
 

alldodge

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Hello all you helpful boaters.......I have a question for you, and hope you can help me with an answer.

I have a house bank of two 6V batteries hooked up to give me 12 volts. The on board charger is a 40A.
I am planning on spending a couple days on the hook at Catalina Island.
If I fully charge my batteries before leaving, and then hook up my portable EM650 Honda Generator which outputs 550VA to my shore power cord with an adapter, will that generate enough power to keep my house batteries topped off for the two days, or would it be best to just use my generator to plug in appliances that I need to use?
My inverter is a 2000W Xantrex and if I use certain larger appliances, it will deplete my house bank fairly quick to below 12V and it will shut off for safety reasons.

Thanks for the help everyone!

What model number is your battery charger?
 

alldodge

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Its a XantrexTrueCharge2 40A

From what I can find it will help but the Gen will not put out enough "IF" the batteries need no more then 4.6 AMP (80% load) from the Gen to keep the batteries charged. Your charger (model TC4012) can draw up to 7.7 AMPs.

There is always efficiency loss when changing from DC to AC or the other way. So if your appliances draw no more then 4.6AMP' then running straight from the Gen will work more efficient.

Info: Volt Amp (VA) = voltage x amperage output or 120x4.6 = 552

charger.jpg
 

SeaEsta-12

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May 25, 2012
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Wow! that was awesome information!
Thank you for that! That is exactly what I needed to know.

Most of what we will run off the house batteries connected to the inverter, are a phone charger, at times a microwave and coffee maker in the morning.

While we are at anchor, we listen to the radio off of the 12V house battery that is on a selector switch and separate from my starting battery.

So, with that information, do you think that the honda gen will be enough to float the batteries that started off fully charged?
We are not running a lot of equipment at any given time. mostly the radio.
 

alldodge

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So, with that information, do you think that the honda gen will be enough to float the batteries that started off fully charged?
We are not running a lot of equipment at any given time. mostly the radio.

I do believe you should be fine for everything except the coffee pot and microwave. A regular coffee pot can pull 5 to 8 AMP, and a small microwave can be about the same.

The issue is if you lets say make a pot of coffee with only using the inverter. Now the bat needs to be charged, you fire up the Gen but the charger might try to pull more then it's max output of 4.6amps. If it tries to pull to much the Gen shuts down, this is also the reason you cannot leave it connected when making the pot of coffee.

Now if you connected the battery charger side of the Gen to the batteries (12V @ 8.3amps max). The Gen would be charging the bats as the coffee was being made, and would continue to charge until brought back up, or once it got close you could run back thru the boat charger.

This is all opinion on my part based on what I'm reading. You could try this; use the coffee pot and microwave while still at the dock prior to leaving and run some test to see what happens when keeping the Gen plugged into the boat charger
 

SeaEsta-12

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Thank you AllDodge!!! I appreciate you quick replies and information. You really helped out a lot.
I am thinking I may be buying a Honda 2000i
 

alldodge

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That would be more then enough, output at 13.3amps.

Might get away with a 1000i, it's at 7.5amps, surge to 8.3 amps so should probably take the startup
 

StarTed

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I have a Honda EU2000I and can speak for its quality. I've used it for years and it has always been great. Its output is 13.3 amps continuous so that should be great but maybe not enough to run both your coffee maker and microwave at the same time. If it's overloaded the breaker will trip and you have to wait a little while before it'll reset. Another problem is if the temperature is down in the low 20s or teens then you may have restart it 2 or 3 times before the oil warms up enough to flow back down and prevent it from shutting off for low oil pressure. I don't think you'll be boating in those temperatures so you should be safe. Keeping it level also helps.

There are many others available now that use the inverter technology so it might be wise to shop around. I'm thinking that maybe 2500 watt might be a little better for the output. Mine will not run the AC unit in my camper and barely runs the microwave.

Good luck and I suggest you run the generator whenever you're using the coffee maker or microwave to keep from drawing all your energy from the batteries. That way it won't take as long to recharge them.
 

wrench 3

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Aug 12, 2012
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As far as efficacy goes your better to run the AC appliances directly off of the generator. Every time you convert the voltage you loose some energy. So you loose some of the power when you charge the batteries and then again inverting it to 110.
I've got two house batteries with total reserve capacity of 550. At anker, I can run the small fridge, cabin lights, water pressure pump and laptops off of the inverter for three days and still have some reserve.
 

fhhuber

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As far as efficacy goes your better to run the AC appliances directly off of the generator. Every time you convert the voltage you loose some energy. So you loose some of the power when you charge the batteries and then again inverting it to 110.
I've got two house batteries with total reserve capacity of 550. At anker, I can run the small fridge, cabin lights, water pressure pump and laptops off of the inverter for three days and still have some reserve.

You lose a minimum of 10% with conversion from DC to AC and might lose over 50%.

By selective operation of loads you can get by on a surprisingly low amount of power. But how you manage the power is what will determine if your setup will be adequate or not.

I've become very fond of 12V LED lighting with solar panels and storage batteries. The LED lights are the best for conserving power.
 
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