What's the most efficient way to charge the batteries? At the mooring ball using the generator or motoring with a load on the engine?
Batteries
- Thread starter RuddyDuck
- Start date
Which has a larger charge capacity - the battery charger or the alternator?
What is the battery bank capacity?
What is the alternator actual output at 2000rpm?
All of the above factor into the answer. Absent more info, a good guess would be the charger.
What is the battery bank capacity?
What is the alternator actual output at 2000rpm?
All of the above factor into the answer. Absent more info, a good guess would be the charger.
In general terms with a stock EOM system I would say it will be more efficient to run the generator and inboard charger. Hours on the generator are usually less costly than hours on the auxiliary engine. Depending on how deeply discharged the batteries are the recharging time will not vary much. Understand that either method will take hours to bring batteries to 100% state of charge as the rate of charge acceptance by the batteries diminishes as the batteries acquire charge. On the average 4-6 hours will do the job.
Running your engine just to charge batteries is not great for the engine.
Without load you can glaze the cylinders.
Typically, the average charger / inverter puts out about 100 Amps at full charge.
A large Balmar will be similar, but it's much more efficient to run the genset.
http://forums.catalina.sailboatowners.com/showthread.php?p=1061319&highlight=glazing
Glazing seems to be a non-issue. Besides, idle speed will get almost nothing out of an alternator out of gear. Most reports are at least 1500 rpm, which gets amperage out of the alternator, which means there IS a load on the engine. If there was no load, the engine temperature wouldn't go up, would it?
Glazing seems to be a non-issue. Besides, idle speed will get almost nothing out of an alternator out of gear. Most reports are at least 1500 rpm, which gets amperage out of the alternator, which means there IS a load on the engine. If there was no load, the engine temperature wouldn't go up, would it?
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Most efficient way would be with solar. But if I had a generator I would use that before I used my main engine
Cylinder glazing
I was warned by 2 mechanics that running with no load for 2 hours per day ( 1 hour morning, 1 hour night) was really not good for the engine, and promoted glazing over time.
Having said that, I would definitely charge with a genset versus engine. Lot more efficient, quieter, etc.
I found that at 1500 rpm, I wasn't getting adequate charge. Needed to run at about 2000 to optimize the alternator.
I was warned by 2 mechanics that running with no load for 2 hours per day ( 1 hour morning, 1 hour night) was really not good for the engine, and promoted glazing over time.
Having said that, I would definitely charge with a genset versus engine. Lot more efficient, quieter, etc.
I tend to believe what my manual says over various yard monkey myths and it says you can run you engine at idle, just to run it up to 3000 rpm for a while every few hours.
another option i have considered is an auto start module for the gen set- there seems to be multiple vendors of this type of product. It is installed to monitor your battery bank voltage and when it hits a low voltage level you have set, it automatically starts the gen set and then runs it until batteries reach the fully charged level - that you have also set- might be worth considering , if living on a mooring.
I am not sure how to "glaze" a diesel or gas engine. If they meant carbon deposits, then there are additives and engine exercises ( vitamins and gym for humans) to help prevent/remove carbon from critical engines parts.
Efficient is a term for engine engineering, but the "ideal" way is to use you genset and a inverter/charger which has charging curves for house batteries for optimum charge. This gives longevity to your expensive deep charge battery(s).
BTW your engine alternator has a crude voltage regulator to charge "high amp output" starting batteries. I would only an alternator to charge a house battery in a pinch. Plus there is a "working charge" between 12.5 and 11 volts which is about 85% of total house battery rating. If you have the Amps/voltage in your charger, then you can recharge (85%) in usually around an hour. Then the next 15% takes hours, which done by a modern charger. Extends battery life by a slow "trickle" charge to "top them off".
Efficient to me is... charge when i need high power demand times. My genset is 9kw and battery charges as a "side issue". Most genets "idle" until Amp load increases. So combine power use on a schedule for most genset fuel efficiency.
Happy cruising and long battery life....
Jim...
Efficient is a term for engine engineering, but the "ideal" way is to use you genset and a inverter/charger which has charging curves for house batteries for optimum charge. This gives longevity to your expensive deep charge battery(s).
BTW your engine alternator has a crude voltage regulator to charge "high amp output" starting batteries. I would only an alternator to charge a house battery in a pinch. Plus there is a "working charge" between 12.5 and 11 volts which is about 85% of total house battery rating. If you have the Amps/voltage in your charger, then you can recharge (85%) in usually around an hour. Then the next 15% takes hours, which done by a modern charger. Extends battery life by a slow "trickle" charge to "top them off".
Efficient to me is... charge when i need high power demand times. My genset is 9kw and battery charges as a "side issue". Most genets "idle" until Amp load increases. So combine power use on a schedule for most genset fuel efficiency.
Happy cruising and long battery life....
Jim...
Guys lightly loading a genset is no different than constantly light loading the engine... Also keep in mind that many inverter / chargers can perform quite poorly on a genset putting out fractions of what they are truly capable of. If you have a well matched genset & inverter charger then running the genset is a good option if you can also use other AC devices while charging...
With either engine or genset charging for more than about 20-30 minutes beyond hitting absorption voltage is very inefficient and is simply a waste of energy...
With either engine or genset charging for more than about 20-30 minutes beyond hitting absorption voltage is very inefficient and is simply a waste of energy...
If you ever feel the need to be further convinced "glazing" is a myth, drive by any roadside truck stop at night.
Great point Don! When we travel with our trailer we sometimes stop at a rest site. They should call those "daytime rest sites". At night those truckers run their tractors all night to run either the heater or A/C! Glaze my butt! You are right on! Chief
Great Point Don.
I'm not an expert, but as w the newer cars, better fuel, cleaner more efficient engines, many of the old engine myths are going away. I'll be look for the glazing on my donuts.
Bob.
I'm not an expert, but as w the newer cars, better fuel, cleaner more efficient engines, many of the old engine myths are going away. I'll be look for the glazing on my donuts.
Bob.