Inverter issue (maybe alternator based)

[contagous]

Hi guys

I have a Cal 28' 1966 "The Pelican" sailboat moored in Seattle WA. I have been a live aboard for around a year now. (cheap rent) in Seattle anyways lol

I'm not a engine head at all, and not great with electric, computers are my specialized field so bare with me on the explanation please. I'll do my best

OK here goes:


I have been running a SPT Refrigerator on the Dock whilst being powered by the on shore power.

http://www.walmart.com/ip/Sunpentown-3-Cu-Compact-Refrigerator/5982314

I am using the boat more frequently this year, so I went out and purchased a 1000W (2500W peak) Inverter so my fridge can be used out on the water.

http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?productId=98228&catalogId=10001&langId=-1&storeId=11151&storeNum=10109&subdeptNum=10544&classNum=11284

Whilst i'm plugged into the shore power, if I connect the fridge to my inverter and power it on, it starts no problems at all...

If i'm not connected to shore power and engine is running, when I plug in the inverter, the inverter beeps tell tell me (low volts) and will not power the fridge...

So I checked my on-board Volt meter, and when i'm connected to shore power it reads at around 13.6 (analogue sorry) volts.

When i'm not connected to shore power and just running on engine at around 1000 rpm my volt meter is showing around 12 volts...


When I spoke to the inverter manufacturer tech, he said that the inverter needed max volts to start heavy things like the fridge, and the beep was a low volt warning, and thats why it was not starting...



A little about my setup:

I have a 12 volt starter battery, and 2 6volt deep cycle golf cart battery's in serial for the house batteries, on a 1, 2, 1+2, off switch. And then I have a Dual battery charger pro from guest to charge those batteries from shore power.

http://www.marinco.com/product/10-amp-dual-battery-chargepro-charger

And my engine alternator to charge whilst running...



OK so my questions and queries:

How to I get my volts up when only running the engine so my inverter will power my fridge?

I've read about people having lots of batteries and such, if this needed?

Is my alternator working properly? How can I check?

I heard about people having different size alternators, How can I check what size mine is?

How much give should be in the Alternators belt?, mine seems tight but can push it in a little bit... I heard about these:

http://www.atomic4.com/ADJ.htm

Maybe I could use one to tighten mine, but it looks like my Alternator is on upside down or something lol, sorry i'm know absolutely nothing about engines...

Anyways, that should do for now, Any Input and suggestions would be great, and thank you for any help or info provided. If you need more info just ask.

Thanks


Dave

[rpowers]

You Need A Bigger Inverter

Hello,

I have found that inverters wattage ratings are always listed as more than actually useful.

In other words, you need a bigger inverter than you think.

Also, you need at least a couple of 12V batteries to power something with the energy (watt) draw of a refrigerator.

Examples:

1) I have a small 700 watt inverter, and it is good for recharging my laptop computer and cell phone, but I won't run my 700 watt coffee maker.

2) I have a 1500 watt inverter that will run my 700 watt coffee maker, but only if I attach two 12V batteries in parallel.

3) I have a 1300 watt space heater that cannot be run by the 1500 watt inverter.

To run a fridge (how many watts?) you'll certainly need more than a 1000 watt inverter. Probably two batteries connected in parallel also.

I just went through this exercise myself (thank gosh for Amazon.com's return policy...).

Also, inverters are much cheaper on Amazon.com than at West Marine (as is most everything...)

Best advice of all: Save all big energy appliances for shore power.

[tenders]

That's a nice fridge and if you have reliable shorepower it makes a lot more sense than the 12V systems that are widely installed in sailboats' coolers (including mine). The 12V systems use quite a lot of power and are not all that practical to use on a boat without either a LOT of battery capacity or a LOT of engine running time.

But I would guess that you do not have enough battery capacity to run a 110V refrigerator and freezer through an inverter for very long at all--maybe not even overnight. A freezer is a big electrical commitment, and 110V reefers, especially small ones, are not very efficient.

That said, things with compressors take several times their running amperage to get started. Your inverter may not be up to providing that much juice and neither may your batteries.

If you're getting 12V out of your battery when the alternator is running and the batteries just came off the shore power charger and with no other load on the batteries, your alternator may not be putting out what it's supposed to. What happens when you're running at 1500 RPM? You should be getting about 12.6V out of the stock A4 alternator, which is still low by today's alternator standards. Also, when you're running the engine and you turn on the inverter with a big load on it like your fridge, you should hear the engine slow down as the alternator starts bearing a load. If that isn't happening your alternator isn't working.

With 12V showing with the alternator running, it is also possible that your batteries are weakened. It's quite common for a shore power charger that's on all the time to weaken batteries to the point that they can't last much longer than a daysail without getting totally drained.

[contagous]

rpowers:

My fridge is only 150W, and i've been told it takes about 4x that to start so 600w, my inverter is 1000W with 2500W peak rate.


tenders:

I am only trying to run the fridge/freezer when engine is on, so when i'm out and about My food doesn't defrost etc... and then if i Sail, I would switch to house batteries only so my starter motor battery wouldn't get low...

On shore I will rely on the shore power, which is most of the year, but for the times I got out, like tripping to Canada soon, I would like to be able to have it working form the Engine power.

Haven't been able to get the fridge powered up via the inverter unless plugged into shore line, the inverter beep with low volts and shuts off, so Haven't noticed a drop in the engine rpm or anything as of yet.

i was wondering about the batteries, I am getting a Hydrometer soon to test them, and when I have my Multimeter I'll check that too.

Thanks guys for the help its really appreciated/.

[hanleyclifford]

A 12 volt output at 1000rpm is way below acceptable. With no load you should be getting between 13.0-13.4 volts. Sounds like you need to upgrade both alternator and battery size.

[contagous]

A 12 volt output at 1000rpm is way below acceptable. With no load you should be getting between 13.0-13.4 volts. Sounds like you need to upgrade both alternator and battery size.

o.o really? people keep telling me the battery setup is ok, But I am checking to see if they are dying on Monday (i think) with a Hydrometer and such.

I noticed my alternator belt was a little loose, maybe 1/2 inch give on it, so trying to tighten it by rotating my Alternator up a little, but at the moment, the Nut wont budge... Also heard of those tighteners:

http://www.atomic4.com/ADJ.htm

but my alternator looks a little different to this, so have to see.

Thanks very much for you input, I will test batteries and post results soon, and also test the voltage o the actually alternator and not my on board volt meter.

Thanks

[hanleyclifford]

The best way to test a battery is with a load tester. It is possible for a battery to test with acceptable voltage and still not be able to deliver its rated amperage to the load. Your voltage meter may not be up to the job of monitoring a system with a load like an inverter like yours. Check it with a digital. If your alternator is the stock 35 amp, it will have a hard time keeping up with the load you have.

[contagous]

The best way to test a battery is with a load tester. It is possible for a battery to test with acceptable voltage and still not be able to deliver its rated amperage to the load. Your voltage meter may not be up to the job of monitoring a system with a load like an inverter like yours. Check it with a digital. If your alternator is the stock 35 amp, it will have a hard time keeping up with the load you have.

Thanks for the info i will testing all this on Monday hopefully, i will post results afterwards.. how can I tell what Amp my alternator is? I don't know if its the stock one or not...

[hanleyclifford]

If you post a picture or two of the alternator we should be able to identify it.

[contagous]

If you post a picture or two of the alternator we should be able to identify it.

OK I'll see what I can do about that Thanks

[Dave Neptune]

Basics?

contagous, I am far from an electricle guru, so I deffer to many on this site for there tutilage. However I am well versed in the basics and there is one thing I have not seen is these posts and that is the connections, especially the grounds and the battery cables themselves. If they are old enough there can sometimes be corrosion inside the insulation that may not allow all of the power to get through.

Dave Neptune

[ArtJ]

The primary issue here is Battery capacity and alternator capacity as stated
above. You can never get the proper battery voltage out to run your
inverter otherwise.

As a aside, why not have gone with a dc powered refrigerator to begin with
and thus eliminate the need for the inverter and the resulting losses due
to efficiency, heat, etc. ? Dometic sells a number of these units as well
as supplemental power supplies so that you can power them directly
from shore power later.

You must also upgrade your wire size when added a high powered alternator,
such as a 100 amp unit. The old fashioned analog ammeter that used to
run the positive lead to the cockpit will both be too small and too long with
bad connections. Replace the ammeter with a shunt based digital unit such
as sold by Blue seas. a volt meter from the same company as also helpful
to be able to see both amps delivered and percent charge.

Tom Stevens of Indigo Electronics has worked out a system , including
a smart 3 stage regulator which insures that the batteries are kept up to
snuff.

Good Luck

Art

[hanleyclifford]

These are the digital gauges Art is refering to. I no longer recommend multistage regulators.

[contagous]

contagous, I am far from an electricle guru, so I deffer to many on this site for there tutilage. However I am well versed in the basics and there is one thing I have not seen is these posts and that is the connections, especially the grounds and the battery cables themselves. If they are old enough there can sometimes be corrosion inside the insulation that may not allow all of the power to get through.

Dave Neptune

The wiring is all good as was only rewired just under a year ago... forgot to mention that, was all done by a qualified Electrician from Lunde Electronics here in Ballard. (12 volt system) So contacts look clean.



ArtJ:

Probably would of been smart, but when My old fridge died, just needed a replacement asap, I'm not a rich man, so I found something that worked, didn't really think about what I would do when not ashore, it was winter and my old one just died... I'm a live aboard so kinda forgot about the rest lol...

I will be testing my Alternator soon, and will post the results I get.

hanley:

This is about as good as photos I can get i'm afraid, its hard to get in there, and its taken with my Cellphone, Don't have camera (it died).






I know they not great and sorry for that.


Thanks for all the help guys

Dave

[tenders]

I'm pretty sure that's a simple stock 35 amp Motorola alternator.

I disagree that a 12V refrigeration system is better for liveaboards. Use your inverter and all its inefficiencies the 2% of the time you're underway. Use the direct AC for the 98% of the rest of the time rather than converting the AC to DC as you would with the DC reefer.

I agree you should clean off and reseat as many of the electrical contacts that you can. Then see what kind of voltage your batteries are putting out with a moderate load placed on them (ie, your engine blowers). Then take the alternator to a shop and see if it's putting out what it should. If not, it will cost less than $150 to rebuild. Or, replace it with a larger one.

In my opinion the information one gleans from an ammeter is not worth the substantial wiring necessary to mount the ammeter in a useful spot. A voltmeter, though, it worth its weight in gold. I have three: an analog one in the control panel, a 0-100% scale voltage meter by the electrical panel, and a digital one above the instruments.