Honda Generator

For versatility, I would get the EU2000i. You can later parallel it with another EU2000i, EU1000i or even an EU3000is if you later decide you need to upgrade. The EU's will sync up with any other EU. As far as the Companion model, I would just buy a set of parallel cables, cut them in half, stick a junction box in the middle with a 30 amp receptacle. That will save you $100+ and is totally safe.

What do you think is going to happen if you plug a 725 W converter into a 500 W generator?

Charger won't draw more than genny can give him, that's for sure.

When the goal is "real" 100% SOC, the difference between 30A and 45A charging current won't be that significant. Especially if they have a pair of 6V and only have to put 110 AH to get it from 50% to 100%. After a few hours at 30A, battery bank will only need few amps of current. But, hey, - let them go for 1000W, we should keep our Japanese friends happy :)

After 5.5 hours on a charge starting at 50% SOC my batteries are down to taking 4A DC, which at about a 85% efficiency is ~65w so not all that much. Luckily the fridge switches to AC power and gives the generator a bit of a load.

Almot wrote:
This is why the OP don't need more than 1000W for charging only, and probably would make it with 500W.

I agree 1000w is plenty, 500w probably isn't enough as a 45A charger can draw ~725W peak, and even a 35A charger can draw ~550W peak.

In terms of charging yes it's {generator} just as effective

I thought we agreed that it's not a generator that is actually charging the battery :)

in terms of total energy required to make the AC power to charge the batteries then no it isn't.

My point exactly. The less power you need, the less efficient generator becomes. When batteries are nearing full stage and go into Float, you need very little power, but still have to run it for hours.

This is why the OP don't need more than 1000W for charging only, and probably would make it with 500W.

I will take a screen shot on my next camping trip, but mine are not that loud as a single

Depending on wind direction, ambient noise, surroundings (open or close), sound reflecting surfaces etc, you results will vary. I've seen numbers as high as 72.

Almot wrote:
ah64id - of course, generator is not charging the battery, it's running the charger that is charging the battery. Didn't know that anybody needed explaining that.

I said you where probably aware, but the wording in your statement was misleading.

Almot wrote:
No, generator is not as efficient for charging as shore power. When load goes down - by the end of charging cycle - with shore power you only use what is needed.

In terms of charging yes it's just as effective, in terms of total energy required to make the AC power to charge the batteries then no it isn't.. but sorta like saying semi-trucks are a less efficient choice than a train, it's very true but trains don't go everywhere.. just like shore power.

The batteries don't care where the converter gets it's power, its all the same once it's turned into DC.

Funny thing about electricity, you always only use what you need. If the converter needs 1A of 115VAC power it's only going to use 3A of 115VAC power, regardless of the source.

Almot wrote:
OTH, fuel consumption of generator doesn't drop proportionally to reduced power. When power drops 4 times, fuel consumption only drops 2 times. When power drops below 1/4 - in those last slow 10-15% of SOC - I am not even sure that fuel consumption would drop any further. Less fumes - don't know, smells the same to me. It may draw 5A current but would still need 0.07 GPH. And I can even tell you more - it will still use a fuel when there is no load :)...

I know fuel burn goes down as I have gotten about 15 hours out of a tank on my EU2000, that's approx 2/3 the burn rate of 1/4 load and there was a slight load on the gen.

Almot wrote:
As to those 59-53 Db numbers - they are manufacturers numbers, everybody likes repeating them, but I wouldn't trust them too much. For Eu2000 at 25ft it's usually in the mid-60s or low 70s with minimal or no load and "Eco" On.

I will take a screen shot on my next camping trip, but mine are not that loud as a single and I don't recall as a pair with the A/C on.

ah64id - of course, generator is not charging the battery, it's running the charger that is charging the battery. Didn't know that anybody needed explaining that.

And - no, generator is not as efficient for charging as shore power.

When load goes down, with shore power you only use what is needed.

OTH, fuel consumption of generator doesn't drop proportionally to reduced power. When power drops 4 times, fuel consumption only drops 2 times. When power drops below 1/4 - in those last slow 10-15% of SOC - I am not even sure that fuel consumption would drop any further. Less fumes - don't know, smells the same to me. It may draw 5A current but would still need 0.07 GPH. I can even tell you more - it will still use a fuel when there is no load.

As to those 59-53 DB numbers - they are manufacturers numbers, and I wish they were true. For Eu2000 at 25ft it's usually in the mid-60s or low 70s with minimal or no load and "Eco" On.

Almot wrote:
RoyB is right. Generators are not very efficient charging devices. You can run a microwave on a generator (has to be at least 1500W then), but getting batteries to really full 100% is a royal pain. Doesn't matter whether it's 1000W or 3000W, when battery is nearing 90%, its charge acceptance rate decreases so it draws a lower current.

The generator isn't what charges the batteries, thou you probably know that your statement is misleading.

Generators are just as efficient as wall power at charging, and one shouldn't charge faster than the other (yes, minor variances based on actual voltage).

It's not difficult at all, doesn't involve any pain or really any work. Just leave a generator running for 12 hours and you are at 100%.

Getting to 100% isn't needed on most camping trips, so hookup to the house between trips and let the batteries get a long full charge again.

Almot wrote:
So it takes long hours, with same noise and fumes as if it were running full power.

This statement makes it very clear you are not familiar with the generators that this thread is about.

EU1000 full load 0.16 GPH, 0.07 GPH 1/4 load. That's not the same as full power. Less fuel means less fumes. 59DB at full load and 53DB at 1/4 load, again not the same.

EU2000 full load 0.24 GPH, 0.10 GPH 1/4 load. That's not the same as full power. Again, less fuel means less fumes. 59DB at full load and 53DB at 1/4 load, again not the same.

As the converter drops it's charge down the generator will change rpm and fuel burn to match the load, making it quieter with less exhaust flow. A generator that is powering nothing but the converter from 90-100% will be below 1/4 load.

RoyB is right. Generators are not very efficient charging devices. You can run a microwave on a generator (has to be at least 1500W then), but getting batteries to really full 100% is a royal pain. Doesn't matter whether it's 1000W or 3000W, when battery is nearing 90%, its charge acceptance rate decreases so it draws a lower current. So it takes long hours, with same noise and fumes as if it were running full power.

Power estimates made earlier are correct - if this is only for charging, 1000W would suffice.

I'd look for lightly used Honda Eu1000i if just for charging the batteries. I'd look at an Eu2000i if you plan to include the microwave oven. Beyond that 3 to 4000 watts necessary to also run the A/C.