Charger, inverter and alternator question

[Vitesse473]

I've read just about every thread on sailnet, and now need to ask for some specific advise on my particular set up.

First off, I have a Dolphin 40amp charger, a Valeo 60amp alternator (Volvo-Penta 75hp turbo diesel, TMD22), 3 wet cell Tudor 140ah house batts and 1 cranking batt. The Tudor batts are original equipment, so about 6 years old. I have no idea if the previous owner maintained them properly. The cranking batt is brand new.

I'm adding a Link 20 battery monitor, and have been shopping for a 1000w pure sine wave inverter to use for running small electronics such as laptop, flat panel monitor, handheld VHF charger, etc while at sea.

So here's my concern. I have used a multi-meter on the house batts, and they are sitting at about 12.2 or 12.4v (at the dock with shorepower connected). My plan was to install the Link 20 to get a better picture of the charging input and Ah output. This would then help me decide if I needed to buy new batts.

Lastly, I am struggling with whether or not I should buy an inverter/charger combo, or keep my Dolphin and simply add the inverter. I am also debating whether I could upgrade to something like a 100amp alternator wilst not having to change the belts, etc.

Any advise to aid in solving my conundrum are appreciated!

[EO32]

My guess is 6 year old batteries are worn. The sitting voltage tells you all cells are ok, but the real test is when you put a load on them. The Link 20 will help you determine their condition.

I lived off grid for 9 years with PV panels, batteries and a 2500 watt Modified Sine Wave Inverter. The new Sine Wave inverters are nice. Most have good three stage chargers in them and will automatically switch over when they detect shore power.

I guess keeping your charger would depend on space.

[jonlgauthier]

Originally Posted by Vitesse473

. I have used a multi-meter on the house batts, and they are sitting at about 12.2 or 12.4v (at the dock with shorepower connected).

If your batteries are floating that low, then you've got a problem with either your multimeter (reads low), your charger (floats low - should be 13.8v @ 25C for wet cells), or you have a bad battery with perhaps a shorted cell dragging down the whole 3-battery bank. Is the bank really charged, or did you measure when you just started charging a depleted bank?

See if you can find the cause of the low voltage before you spend any money, then proceed from there.

[Vitesse473]

Originally Posted by jonlgauthier

Is the bank really charged, or did you measure when you just started charging a depleted bank?

See if you can find the cause of the low voltage before you spend any money, then proceed from there.

The batteries had been sitting on the charger (shorepower connected) for days. I'll check again when I am on the boat tomorrow. I have a feeling my solution will be to replace the batteries entirely. I'd like to have more Ah anyway.

The question then becomes whether or not my alternator would be able to handle charging larger batteries within an acceptable amount of time. I had planned to run the engine no more than 2-3 hours per day during our 10 day Baja Ha Ha event. I guess having larger battery capacity run down to 50% means I may be able to go longer than 20-21 hrs without running the engine, but I'll have to run the engine longer to recharge them. Potentially "six-of-one, half-dozen of the other."

[btrayfors]

Vitesse473,

I agree that your 6-year old flooded batteries are likely near the end of their useful life. And, since you don't know their history or how they have been treated, it would be best IMO to start with new batteries.

The Dolphin 40A charger is a high-end smart charger which should be able to maintain your batteries just fine at dockside. The important thing is to keep them as fully charged as you can when you're not actually using them while cruising.

There is a wide range of inverters available, both pure sine wave and modified sine wave types. You might examine your needs in some more detail to know exactly how you plan to use the inverter. That would drive your decision as to what kind you need and what capacity. For example, a laptop can draw a lot of current (6-8 amps or so at 12V...about the same as electric refrigeration). There are 12V power supplies available for most all laptops; one of these might be a better deal than trying to power the laptop with a generic inverter, as the losses would likely be less, and if you had this option you might get by with a smaller inverter.

Now, if money is no object, think about a high end inverter-charger like the Victron Phoenix Multi-Plus. It does just about everything, is pure sine wave, has a 120A smart charger built in, puts out 2,000 watts @ 110VAC continuous, smart relays, can be chained, etc., etc. and will only set you back about two boat units :-)

Bill

[bobfindlay]

I saw in your post that you are running two alternators on a tmd22. how did you mount the second alternator? can you direct me to any parts you have used? I am hoping to add a large 200amp balmar alternator but I'm not sure how much room I have. I am in Vancouver trying to source parts while my boat is in the UK.
Regards,
Bob

[Maine Sail]

Originally Posted by Vitesse473

The batteries had been sitting on the charger (shorepower connected) for days. I'll check again when I am on the boat tomorrow. I have a feeling my solution will be to replace the batteries entirely. I'd like to have more Ah anyway.

The question then becomes whether or not my alternator would be able to handle charging larger batteries within an acceptable amount of time. I had planned to run the engine no more than 2-3 hours per day during our 10 day Baja Ha Ha event. I guess having larger battery capacity run down to 50% means I may be able to go longer than 20-21 hrs without running the engine, but I'll have to run the engine longer to recharge them. Potentially "six-of-one, half-dozen of the other."

If these are wet cell batts they will "accept" only about 20-25% of their 20 hour Ah rating in charge current. This means the most they will accept, and only when at a very low state of charge is about 70 amps max for a relatively short period of time.

Sounds like your Dolphin charger is toast if it is on and the batts are at 12.2 volts. For inverters check out the Xantrex Prowatt SW1000

I personally do not like combo inverter chargers..