Assuming a 85% efficiency, a direct calculation is...I wonder how many hp this represents?[600Amp 120VAC]
Hey, Jim, no good adding to a supposed quote of Capta! He never said "600Amp 120VAC." In fact, no one did.Assuming a 85% efficiency, a direct calculation is...
82 HP continuous load.
Jim...
My engine is only 86hp. humm......Assuming a 85% efficiency, a direct calculation is...
82 HP continuous load.
Jim...
Of course, you are right. What's it they say about computers? "Garbage in, garbage out." Gotta put in all the info to come up with an answer.Hey, Jim, no good adding to a supposed quote of Capta! He never said "600Amp 120VAC." In fact, no one did.
I just took 8kW and divided it by 13.5V to come up with 600A.
If you take any quote and interject [ bracketed]. It indicates the Bracketed item was interjected by some one else for clarity or other reasons. It is called [SIC] or ...no good adding to a supposed quote of Capta!
Most Diesel Engines are fairly high efficiency engines, mainly do to high compression ratios.Power In = Power out - Power loss from efficiency.
I agree. I didn't find weight info either, but from the FAQ "You really need at least 10 kWh of lead-acid batteries to optimize the system". Weight matters. A standard fixed generator will weigh hundreds of pounds, but is designed to run whenever and doesn't mandate a massive bank of batteries. (In most use-cases the installation of a generator allows the owner to reduce the size of the house bank).Here's my summary view on this.
1. If I had a boat big enough to accommodate this, I would prefer to have a separate generator. I don't want to run my main engine as a generator. It's big, it's loud, and it's expensive. It's too big for the job. I much prefer a smaller, very quiet generator for AC loads at anchor and charing batts, making DC when underway.
2. If you did this, you'd need a specially engineered, custom mount and coupling for that huge alternator. I can't imagine water pump bearings, or even front crank bearing lasting very long with that load.
Yes, but the "big wallop" implies running the main engine at significant speed (way above idle) to generate that HP. I don't have AC currently but thinking hypothetically; that would wake me up (and disturb others nearby). So the system would need to be sized with adequate batteries and inverter power to run AC all night. Many of us struggle to keep up with running a small Danfoss 3Amp refrigerator on the hook, nevermind AC.Part of the deal with the battery bank in this system is it being able to take a BIG whallop of charge quickly.. The lithium batts are better suited for that, but the huge lead acid bank they talk about could work well with it too.. With Li batts, the entirety would be lighter than a separate stand alone generator system and probably burn less fuel overall.. except if taking the case of running a generator all night to have air conditioning.. More pertinent to us folks living in the south 90's.. (90 days of 90+F at around 90% humerditty)
You hit the nail right on the head. I don't care about fuel efficiency. My engine is rated at 0.42 GPH at 2500 RPM (cruise is 2500 to 3000). What I'm concerned about is noise, having to attend the main engine as it's charging, and the amount of time proper charging takes. I do care about charging efficiency, to reduce unnecessary noise, and speed up the charging process.So. what I wonder is how much Diesel is anyone using to generate electrical power? You are not stressing anything mechanical by being inefficient, you just waste some fuel. But if that particular amount of fuel is pretty much "in the noise", and you further reduce "in the noise", did it really matter. This is the part I really have no idea about.
So.. is this efficiency for electrical power generation important? Or is this a very nice solution, but there really was not a problem that needed to be solved in the first place at least for most of the applications here (recreational boating).
The reason it tapers off is that the Charge Acceptance Rate of your batteries drops as the charge level increases. All lead batteries have that issue, although the AGM and Firefly batteries have better (faster) CAR capabilities. There's lots of information on the web about that. Lithium batteries would accept all you can give them. Different animal.What I would really like, and I may indeed design and implement some day, is a dual-mode engine controller. One mode is propulsion, which is normal propulsion operation, but a simple one-button start. I purchased a generator controller years ago with the intent of doing this on my Catalina. The other mode is generator, where you're sitting at anchor and just need to charge batts.
I've noticed recently that during bulk mode my bulk charging current drops off as the voltage comes up. I don't think this is a desired effect. I thought one wanted max current until you hit the accept voltage. (Max current is according to the recommended maximum charge current for the bank, with consideration for max alternator current.) I don't know why it drops off, maybe the alternator needs to spin faster for 100A at 14.0V than it does at 100A and 13.5V. Or maybe it's just a design shortfall in the Link 200-R. I'v also noticed that once I hit accept, I can slow the engine down quite a bit while maintaining the 14.8V accept voltage. So, what I think would work well is a generator mode system where neutral is sensed, for safety, and then the engine speed is controlled by the charging system, just as the field current is: controlled together, to achieve the most engine speed efficient charging possible.
I could have a pair of buttons by my electrical panel: generator on, generator off. I could also set it to run automatically, especially for when I'm sailing, and maybe even have a rotary selector to select how far I want to discharge batts before generating, and also set preferred times of day, and times not to run - like when we're sleeping. A manual lockout for when we're entertaining, or swimming, etc.
(How do you guys feel about the main engine running for generating while you're not on the boat?)
Larry, perhaps I should have been more clear. It's not the current tapering during acceptance mode, which is expected, it's that my current tapers off during bulk mode, at constant engine RPM. I think bulk current should be constant, with voltage coming up towards the acceptance voltage.The reason it tapers off is that the Charge Acceptance Rate of your batteries drops as the charge level increases.
Wouldn't want that happening on my boat. But I have a skeptical opinion of electronics on boat being sufficiently reliable to do something like that and never have a glitch.How do you guys feel about the main engine running for generating while you're not on the boat?)
I think the acceptance rate normally does taper off during bulk charge, and also your alternator output normally declines as it heats up.Larry, perhaps I should have been more clear. It's not the current tapering during acceptance mode, which is expected, it's that my current tapers off during bulk mode, at constant engine RPM. I think bulk current should be constant, with voltage coming up towards the acceptance voltage.