50 amp output on a Honda or Yamaha 1000
I want to remind eveyone of my earlier post that said quite clearly that trying to supply a 50 amp charger from a Honda EU1000i is a mistake. When making calculations of AC power required to supply the output of a battery charger one must be very careful. For example, the max output of the battery charger is likely 50 amps at close to 14.4 volts (not 12 volts) and as a result this requires more power from your genset. The reason it is 14.4 volts is that it needs to develope a high voltage to shove all those amps into your batteries. In addition, as Gord indicates, the efficiency of the charger must be taken into account. That efficiency may be about 80% or it may be slightly worse. Thus if you want to supply a 50 amp charger (when it is putting out 50 amps) then you need Power = (Volts x Amps)/efficiency. That is (14.4 x 50)/0.8 = 900 watts (or more if efficiency is less). This would mean that the genset would have to output 900watts/120volts = 7.5 amps. The Honda and Yamaha 1000 watt (maximum) can output 900 watts continuous. They are on the very edge of being able to supply a 50 amp charger. The max continuous rating is 7.5 amps at 120 volts. You are truly on the edge of a trip. As I indicated earlier I talked to a person who bought a Honda EU1000i which outputs 7.5 amps. His 50 amp charger immediately tripped the breaker on his new Honda genset. He was able to talk the dealer into allowing him to return the generator and moving up to a Honda EU2000i. Note that the 2000i despite its name outputs 1600 watts continuous (2000 max for a very short time). The point I am making is don't buy either the Honda or Yamaha 1000 gensets if you have a 50 amp charger. The maximum I would try is a 40 amp charger and even then I would check out the actual efficiency and initial inrush current rating and then I would leave at least another 10% margin.
I want to remind eveyone of my earlier post that said quite clearly that trying to supply a 50 amp charger from a Honda EU1000i is a mistake. When making calculations of AC power required to supply the output of a battery charger one must be very careful. For example, the max output of the battery charger is likely 50 amps at close to 14.4 volts (not 12 volts) and as a result this requires more power from your genset. The reason it is 14.4 volts is that it needs to develope a high voltage to shove all those amps into your batteries. In addition, as Gord indicates, the efficiency of the charger must be taken into account. That efficiency may be about 80% or it may be slightly worse. Thus if you want to supply a 50 amp charger (when it is putting out 50 amps) then you need Power = (Volts x Amps)/efficiency. That is (14.4 x 50)/0.8 = 900 watts (or more if efficiency is less). This would mean that the genset would have to output 900watts/120volts = 7.5 amps. The Honda and Yamaha 1000 watt (maximum) can output 900 watts continuous. They are on the very edge of being able to supply a 50 amp charger. The max continuous rating is 7.5 amps at 120 volts. You are truly on the edge of a trip. As I indicated earlier I talked to a person who bought a Honda EU1000i which outputs 7.5 amps. His 50 amp charger immediately tripped the breaker on his new Honda genset. He was able to talk the dealer into allowing him to return the generator and moving up to a Honda EU2000i. Note that the 2000i despite its name outputs 1600 watts continuous (2000 max for a very short time). The point I am making is don't buy either the Honda or Yamaha 1000 gensets if you have a 50 amp charger. The maximum I would try is a 40 amp charger and even then I would check out the actual efficiency and initial inrush current rating and then I would leave at least another 10% margin.
. again, thanks to all...even those that think i am a bit eccentric, (i agree), for needing, or actually wanting, this kind of capability. better to have and not need than to need and not have! yes, my independence is a personal thing. i have no real access to shore power and pulling the boat or batteries regularly to charge them is something i would prefer not to do for multiple reasons. and sailing marina to marina hoping to find and get gouged for a transient berth isn't my idea of independence. i don't use much power truly but its there if i need it and/or i am away from port, vehicle, or sunshine. i would like a motor w/ an alternator but it is weight prohibitave on my 23' (and 5-6W is about all they put out)....my small solar does that. really, here's the tentavive plan. 80-100W solar via a charge controler. about a 30W charger. (marine or not probably doesn't matter except for enviromental concerns if i switch it through the same charge controler since the controler handles the V peak). and possibly a Yamaha 1000W back-up. yes, this is overkill for my boat right now. except for the small output Yamaha but weight and size too are considerations. but hopefully, when i move to a bigger boat the good stuff will go with me. regards~ william btw: i'm about to order new rigging too....one size larger!