The 12v MultiPlus 3000 needs a little under 1800 watts to charge at full power. The Honda EU2200 is the champ but the Chinese inverter generators are pretty good for around 1/2 the money if that’s a factor. If you go Chinese check out Pulsar/Westinghouse. They make the portables for Onan and I have had good luck with them.
The Honda EU2200 holds a gallon of gas and will run around 4 hours charging the batteries so you’ll be able to recharge twice before filling up if it’s a 12v setup.
If it’s an occasional thing and you’re not in a hurry to charge the batteries the EU1000 is the same money but it’s a tiny little generator that takes up a lot less room and is much lighter. It will work nicely with the MultiPlus set to 7.5 amps on power assist and a full tank (1/2 gallon) will charge the batteries once.
Hey
@dog_house
Very Informative Post 👍. We use to carry a 2200 Honda & used it so rarely, we decided to remove it from under our bed.
So reading your post sent me down a short rabbit hole this morning; I have AGMs & only 250Ah so my system does not rate for this ,,, but yours 😁🙌 !!
With a large LP4 & even with
@runswift9 300Ah ( if 3P 100, I assume a Max charge current of 300 amps ), a DIYer can take advantage of that. If you have tested your PM Alternator in different conditions, do you have an idea ( a range in different parameters; idle, air conditioning on, highway, etc ) of what you are getting into you LP4s with a direct charge system ?
A few years back, the new owner of my 2018 blew the 70amp up fitter fuse which the Rolls 250Ah AGMs were directly charging on. As the max charge current for those batteries are around 70amps ( which is a bit weird as the written spec & the label on the side of the battery are different 70amps on the spec & 83 amps on the battery ), and the upfitter fuse will be “slow to blow”. The difference was in “The Users” ,,, I understand how the system I designed works & the new owner didn’t ( I educated him on the details after he let the batteries run down to an inoperative voltage ,,, the result is they had little resistance to the available current 😳 ). So my design limit of amp draw was the 70 amp fuse. It is simple & effective if the DIYer understands how to operate it, but it requires a current limiting system ( which is onboard ) to get the AGMs past the SOC so the resistance will self limit. That onboard system is the 45amp 120vac charger & Honda Generator. I never had to use it ,,, not once ,,, we just PM Alternator charge.
Blaa Blaa Blaa; With 300Ah LP4 and our conservative 12vdc use & the PM alternator we would not need our Honda 2200 onboard either.
I assume you can get ~ 150 amps from your PM alternator ? That beats the Victron’s 120 amps ,,, But my ticket is only in the cheap seats so I can’t see the stage clearly 👿.
What say You ?