Yanmar vs Volvo

[b_rodwell]

I have a Lagoon 400 S2 with 2 x 40 HP Yanmar motors. My cruising buddy has a Fountaine Pajot Lipari 41 with 2 x (I think) 40 HP Volvo motors. When using the motors to recharge the house batteries, he seems to do it a lot faster. This is probably partly because I have 600 AH of house storage and he has around 400 Ah. However that does not seem to explain all the difference.

Is there any reason for this charging time difference? Is there anything I could do to make my recharging faster?

Thanks

Brian

[Kenomac]

Sounds like the alternators and/or the battery chargers are different. The alternator sends the current to the battery charger not the engine. You could increase the size of your battery charger if under-sized or add a second charger. Adding a second charger will also add redundancy to your system.

[daletournier]

This is not related to the engines you have, its charging system and battery related, assuming the engines are running at similar rpm.

[Paul L]

This isn't directly related to Volvo or Yanmar, or to your battery charger. The battery charger is run off of AC from the dock or a genset and doesn't come into play when Charging from the main engine. Charging via the engine is through the alternator. It has a regulator, either internal or external, that regulates the charging amount based on the alternator capacity and what the batteries need. Many boats have changed from the original alternator/regulator to third party ones with higher output. So the OP is really comparing apples to oranges.

[belizesailor]

b_rodwell, as posted this as nothing to do with engine type, but with charging system and battery configuration.

Finding out the following about both systems will help solve the mystery:

Alternator outout capacity?

Type of regulator (internal or external)?

If external, what make/model?

Battery type (FLA, Gel, AGM, ...)?

[Stu Jackson]

Originally Posted by b_rodwell

I have a Lagoon 400 S2 with 2 x 40 HP Yanmar motors. My cruising buddy has a Fountaine Pajot Lipari 41 with 2 x (I think) 40 HP Volvo motors. When using the motors to recharge the house batteries, he seems to do it a lot faster. This is probably partly because I have 600 AH of house storage and he has around 400 Ah. However that does not seem to explain all the difference.

Is there any reason for this charging time difference? Is there anything I could do to make my recharging faster?

Thanks

Brian

Brian,

Reading comprehension 101, it's your alternator(s).

*************************
Hitachi/Yanmar Alternators: (by Maine Sail)

Some alternators though, such as those made by Hitachi and found on Yanmar diesels, are dumber than a pound of beetle poop. Actually, to the alternator, they are pretty smart but to your batteries and the speed of charging they are flat out stupid. Why?

Hitachi alts with dumb regulators, and some others, limit voltage but also reduce voltage based on alternator temperature. This is a self protective feature installed in the internal dumb regulator to prevent the alternator from cooking itself. Remember voltage is the pressure that allows more current to flow. So, if we reduce the absorption voltage, then we also reduce the current the alternator is supplying.. The battery simply will not accept the same current at 13.4V that it did at 14.4V and as a result the alternator will run cooler. What do you suppose this does to your batteries over time.......?

The problem is that when cold you will get 14.3V to 14.4V out of the Hitachi but as the alternator heats up the dumb regulator begins to reduce the CV/voltage limit based on the alternators internal temperature. It is not uncommon to find a Hitachi alternator at 13.4V when hot. This is REALLY, REALLY DUMB....

If you have a dumb regulator, and notice the voltage dropping, it is likely a temp compensated dumb regulator. Get rid of it or plan to buy new batteries more often.

If you have a temp compensated alternator or a Hitachi alternator on a Yanmar you really are in dire need of external regulation if deep cycling a larger battery bank.

This is from:

http://forums.sbo.sailboatowners.com...d.php?t=125392

and these, too:

http://www.cruisersforum.com/forums/...on-125843.html


http://www.cruisersforum.com/forums/...or-142083.html

[jamhass]

A couple of important items have been overlooked in the above replies.

1. Are your electrical demands the same? It's very possible that your batteries are far more discharged than your friends.

2. If your loads and charging systems were identical, it is very possible that your batteries would take longer to charge. Why? Because you batteries at 600 ah are not as discharged as you friends, and thus cannot accept as much current.

3. Are the charging parameters the same as your friends? It is quite possible that you have a lower threshold for switching charge modes, thus increasing charge time

[b_rodwell]

Thanks for all that. I believe I now understand the issues and the steps I should take to get lower charging times.

Cheers

Brian