Carver 466 - charging house batteries via generator?

[luvnlifeIV]

On our 2003 Carver 466 we have 2 8D house batteries which run the fridge and ice maker via the inverter if we want for a short period of time. When we first leave the slip it will run them for about 6 hours then we have to go to the generator. Question for other 466 owners: does the generator charge the house batteries when running or not? Ours appear to only charge fully back up when we get back on shore power as we spent the last 4 days out and after the first 6 hour discharge, even after running the generator with the battery chargers on, we would only get 1 - 2 hours of inverter use after that.

Thanks for any feedback.
Doug

[Ramsport47]

The generator will do everything that the shore power will do. You do have to make sure you switch the selector from shore to ship, and turn on the generator breakers on the panel, but it is large enough to power everything that shore power does

[g36]

in addition to the previous comment a couple things come to mind. to maximaize the amount of energy put back into the batteries while running the genset you will need a high amp batttery charger. you are basically not doing anything if you only have a 20 amp-40 amp charger trying to recharge batteries while on the hook. this would be fine while at the dock but it will take forever out on the water. i can run my boat for 2 days easy without recharging using lights, tv, satellite antenna, 2 fridges . have also replaced my interior and exterior lights with leds which use almost no energy when on you might want to look into bulb replacemnts also. if you are only getting 6hrs then you might want to load test your batteries to see if they are operating properly and not weak or a bad cell you dont know about. the fridge should use around 6-8 amps dc 6 hrs should not be draining them this fast. what else are you using while out? tv, dvd etc these arent real battery hogs either. theres lots of articles on the internet about battery mainiance and recharging. one more thing best rule of thumb on keeping your house bank batteries in good shape and maximize their life if only using about 50% of their capacity and not deeply discharging them. if you have run them down already numerous times you may have already reduced them to nothing. a good battery monitor will help you keep this from happening. i use this one, cost around $120or so on the net
http://www.victronenergy.com/battery-monitors/BMV-700

[After Taxes]

Absolutely, your generator is charging your house batteries. The issue for you, is how long are you running the generator to obtain a recharge, or, how long do you need to run the genny to obtain the charge? You didn't say how long you ran the genny.

It's likely that your generator run time was simply insufficient to bring your house batteries back up to 100%. You are probably replacing only a partial amount of the amp-hours you need. When you go back on shore power, you're on overnight or longer, giving your batteries the full charge. The problem, as another writer mentioned, is that we are just guessing when we run the genny.

We need a 'fuel gauge' for the batteries. Wouldn't that be nice? There is such an instrument. Available at West Marine.

I was guessing for years, until I saw one of these on a friend's boat, and later installed one myself. It tells you the exact percentage of battery power left, or in volts if you prefer that information. It's also a gas saver, because you know when the battery is full and you don't need to run the genny any longer.

http://www.xantrex.com/power-products/p ... nitor.aspx

[CYO Admin]

How old are the batteries?

[Hugo]

Take a look at the following PDF.

http://www.eastpennmanufacturing.com/wp ... t-0194.pdf

A typical new 8D battery will give you about 245 amp hours before dead but that's really 122 since you don't want to discharge them below 50% capacity. If you have two wired in parallel you have roughly 490 amp hours of which 245 is usable with 50% left. That should run your fridge (let's say 8 amps) for about 30 hours before you go below 50% capacity. That's probably at least two days as the fridge won't draw current nonstop. keep in mind that as batteries age they loose capacity so you may be well below this amp hour rating depending on the batteries age.

What is the voltage of your batteries after you shut engines down on the hook and after 6 hours?

A simple ammeter will tell you what the current draw is on the batteries if you don't have a battery monitor.

If you're fridge is the only draw on the batteries and is 8 amps, that's 48 amps after 6 hours give or take if it ran constantly. You get the idea...

I also have a Victron BMV monitor and it's pretty good and accurate at telling you how much current in being drawn from batteries, voltage, etc. It's sort of a must if you're going to spend a lot of time on the hook.

[Lyndon670]

I have the same setup on my 506.

Two points of interest. When I bought my 506 in February of 2014 with a tick under 200 hrs on my Volvos, we had a similar charging/recharging issue. After some basic diagnosis, it turns out that both alternators were suspect - they were charging but not putting out enough to do the massive battery bank. I also replaced all of the batteries on the boat too. In for a penny, in for a pound. My point or rather my question is - how old and what condition are your batteries? We have a rough service life up here in the northern climates and it's rough on batteries sitting dormant even if fully charged. My rule of thumb on my batteries in all my boats has been 4 years and I become suspect.

Also, your inverter supplies power to your TV, entertainment centers, and icemaker AND bridge fridge if you have one.

Second, the inverter system that we both share has the digital display that shows all of the information that the gauge that After Taxes suggested. Just cycle through the menu and you will see all of the data.

And, as Hugo suggested - battery management is the key. When I anchor out, which I do a lot, I only run off the batteries from when I go to bed until I wake up. And then I fire my genny. The worst thing for a genny is not to use it. They don't like being shelved. I never go more than an overnight (say 12hrs MAX) with out firing my genny.

[luvnlifeIV]

All,
Thank you very much for the comments. I replaced all 4 8D batteries last fall (2 for house and 2 for engine starting) so they are basically new. I suspect the inverter/charger is not enough to charge them when running the generator since I have left it running for 24 hours with minimal charge to the batteries. I will look into one of the battery monitors to see what is going on.
Thank you very much as your comments confirmed my suspicions.