The Honda 12V DC output is a max of about 8A and the voltage is UNREGULATED. If you place a DVM on this output you will see upwards of 25V.... Not good for 12V batteries. If your batteries ever got to the point in the SOC curve where they require less than 8A then the voltage of the Honda's DC output would be come dangerous to the batteries.Related question, what is the most effective way to charge your batteries with a generator? Connect the DC output of the generator to your batteries, OR have the generator convert to AC and plug in the boat's battery charger which converts it back to DC. The 2nd is safer since I have more faith in the battery charger feeding my batteries properly. Curious if anyone has compared the 2 ways to see what is faster. If I only want to run the generator for 1 hour, what gives me the best short term charge?
The EU1000i and EU2000i both have the identical specs for the DC output 12V and 8A. However the DC output is unregulated on both of these units and DC voltage can climb as high as 25V +/- ...The Honda 1000 only puts out 8 amps direct DC and the 2000 puts out 16.
Run the generator and stick your DVM into the 12V plug,. You will see upwards of 25V. If it was regulated you would see a max of about 14.4V regardless of EcoThrottle position...MaineSail... I have the manual here for my H2000 and it says the DC is rectified for charging 12V batteries, I do not believe the voltage would exceed 14-15 volts as exceeding this voltage would be a no-no for Honda to accept on it's generators. But I do see that it mentions the DC voltage is not regulated.
I don't know why you would go to all that trouble for 8A when a portable battery charger capable of supplying significantly more amperage can be plugged into the 120V outlet..Ok.. MaineSail... You are right... I measured varying voltage from the 12V DC side... and since I've never used it for this purpose (charge batteries) I never had a need. I see why others are getting 'boiled', or failing batteries after using the DC voltage.
The fix I guess and I will do it is to purchase a 12V marine/auto voltage regulator that really is inexpensive anywhere from $13-75 for auto use and $60-200 for marine use... I will get the most robust sealed auto use regulator and install it in into the housing conveniently located so it could be replaced if need be. That then solves the issue with the generator... but we'll see as I never use it at all and is just a paperweight in the cockpit lazarette.
This has perplexed me, that a reputable company like Honda, would not put even a simple Zener Diode regulation.Run the generator and stick your DVM into the 12V plug,. You will see upwards of 25V. If it was regulated you would see a max of about 14.4V regardless of EcoThrottle position...
I want to consider your power factor, but I am not sure if I understood right.One other thing to consider (something I got caught on...) - in AC, power is NOT just volts x amps: there's a "power factor". So my 40 A TrueCharge charger drew (40 * 14 = ) 560W, but it drew about 11 Amps at 120 VAC because of the 0.4 power factor. So it LOOKed like a 1000W charger could run it, but it couldn't.
The generator is sometimes used away from the boat and the 12V may be used for air pumps or other uses... I now it doesn't have to be regulated but using the generator with a 120V charger is carrying two pieces of equipment around. I never use the generator for charging batteries in the boat but it may be used in an emergency.I don't know why you would go to all that trouble for 8A when a portable battery charger capable of supplying significantly more amperage can be plugged into the 120V outlet..
Yup. That's because the voltage and current are out of phase. If you want an explanation, look up "power factor". It's an AC-thing... As for "where did the power go?", it doesn't. It's still producing about 600 Watts, but it's also producing what's called Vars ("Volt-Amp-Reactive"). And unfortunately a "1000 Watt" generator is more correctly called a "1000 VA" generator: in other words, it only can produce 1000 Watts if the power factor is 1.0.I want to consider your power factor, but I am not sure if I understood right.
@druid , you consumed 11 amp of 120VDC to make 40 amps at 14VDC?
Jim...
Might be something else going on (assuming everything was measured accuratly). Here is the spec for that charger http://www.xantrex.com/documents/Discontinued-Products/TC20_40(445-0050-01-01_Rev-A).pdfSo my 40 A TrueCharge charger drew (40 * 14 = ) 560W, but it drew about 11 Amps at 120 VAC because of the 0.4 power factor.
I had to read that Power Factor wiki article 3 times to begin to understand.If you want an explanation, look up "power factor". It's an AC-thing... As for "where did the power go?", it doesn't.
I agree with @walt.Might be something else going on (assuming everything was measured accuratly).
You pegged it. The shore power charger will treat your batteries much better and in some cases charge much faster. The DC outputs from most small generators is pretty small.Related question, what is the most effective way to charge your batteries with a generator? Connect the DC output of the generator to your batteries, OR have the generator convert to AC and plug in the boat's battery charger which converts it back to DC. Or, option 3 may be to connect both the AC via battery charger AND the DC to the battery.
The 2nd sounds safest since I have more faith in the battery charger feeding my batteries properly. Curious if anyone has compared the 3 ways to see what is faster. If I only want to run the generator for 1 hour, what gives me the best short term charge?
and is unregulated on the Hondas. Don't do it.The DC outputs from most small generators is pretty small.