Honda EUx000i generator: 12V OK? (1 Viewer)

[e9999]

question for yall Honda generator experts:

as we all know the Honda EUs are the ticket. The EU1000i and EU2000i are the best ones out there for camping it seems. So I've been looking for a used one for a while now.

One thing that's nice is that they have a 12V outlet for battery charging in a pinch. Good to have around.

I was checking out a used EU today and something caught my eye: when the gen was idling the 12V plug showed about 14V which seems fine. However, when the gen was revving up because of a heavy 120V load, the 12V plug showed 22V -with no load. I was wondering whether that is OK or not. Is it because of the high rpm and no load? Does yours rev up when it's only connected to a truck battery or not? Does it show 22V too at high rpm no load or is there something wrong with the electronics on this one?

Thoughts?

TIA

added: I did see in a Honda manual that "the 12V DC output is not regulated" whatever that means...

 

[e9999]

well, since nobody knows (or cares) on MUD so far, I asked the second best source: Honda Tech support.

According to the guy I talked to, it's normal for the 12V plug to show a higher voltage with no load. He didn't seem concerned. So, it's probably OK.



On another note, I was looking at the plug needed for the 12V attachment cord and it's definitely an odd size and shape. Not sure where one could get a plug like that besides the OEM full accessory from Honda ($20+ on ebay).

But a quick check revealed that a common spade crimp-on connector fits fine in each slot, so a quick and inexpensive DIY approach could use 2 of those, a length of wire of your choosing and a couple of alligator clips (with good color coding) for a quick and much cheaper custom solution. The outlet is rated at 8A, so looks like 16AWG should be OK for 10' or cord or so (20' both ways) - please correct me if wrong.

 

[squeegeeboy]

According to the guy I talked to, it's normal for the 12V plug to show a higher voltage with no load. He didn't seem concerned. So, it's probably OK.

Yep, it's normal for an unregulated supply. Here's a pretty good explanation of what that means, some math included:

Regulated vs Unregulated Power Supplies

A short and highly oversimplified summary: An unregulated power supply is a straight ratio of the source voltage. Generally speaking, as load increases/decreases, so inversely will the output voltage.

A regulated power supply has additional electronics after the transformer to more or less guarantee the output voltage despite variances of the source voltage. Costs more, and isn't always necessary depending on exactly what you're going to do with the electricity.

You can charge a 12V battery from an unregulated supply, just keep an eye on it with a voltmeter and stop when it's fully charged (exact voltage varies with precise battery type, see the manufacturers spec).

I don't own a Honda generator, so I can't help with the rest

Robyn

 

[e9999]

Yep, it's normal for an unregulated supply. Here's a pretty good explanation of what that means, some math included:

Regulated vs Unregulated Power Supplies

A short and highly oversimplified summary: An unregulated power supply is a straight ratio of the source voltage. Generally speaking, as load increases/decreases, so inversely will the output voltage.

A regulated power supply has additional electronics after the transformer to more or less guarantee the output voltage despite variances of the source voltage. Costs more, and isn't always necessary depending on exactly what you're going to do with the electricity.

You can charge a 12V battery from an unregulated supply, just keep an eye on it with a voltmeter and stop when it's fully charged (exact voltage varies with precise battery type, see the manufacturers spec).

I don't own a Honda generator, so I can't help with the rest

Robyn

thanks for the info
had a look at the link but did not seem like they were talking about the situation here.

but are you saying that if I were to connect the gen to my battery and I kept it on it would keep going and end up overcharging/boiling the battery?

 

[squeegeeboy]

It's the same principle, just a different application in the link.

Yes, if you leave a 12V battery connected to it and forget about it, you'll eventually boil it to death. It may take a short time or a long time to kill it, though, depending on the exact battery tech, capacity, and other things like ambient temperature.

Robyn

 

[e9999]

all right, made myself a 12V battery charging cable.

Used 16 gauge wire. Should be plenty good for 8A (gen max). Length doesn't matter much, you'd just lose a bit of voltage, no problem for this application. I made the length about 10' and I have another 9' coiled extension if I need it. Couple of spade crimp connectors for the generator side and some shielded ones for the other side to make a modular extension/clip end. The clip side is M/F coded so I can't connect it backwards. I'm using similar arrangements for my fridge, inverter etc.

I tried it with the generator on a discharged battery with about 6V left. Fired up just fine, generator fuse didn't trip. Wire is not getting warm. All good. Brought the battery from 6V to 10.5 in about 10 mins. I stopped at that.

I would have used completely shielded alligator clips for extra safety but the only ones I could find easily here were 10A and I thought it was a bit close to the 8A of the generator fuse. I might still do it, a bit safer at the battery.

Main potential downside of the DIY generator side with the 2 spades is in the unlikely event that they would somehow disconnect themselves from the generator and manage to short themselves out. Highly unlikely, they are in there very tight but I'll keep an eye on that in the beginning. Also possible to connect them backwards, but I did put the big orange flag so I'm good. If I get too worried, I'll make a rigid support for them. No biggie. And won't lend it out for safety. Still, if somebody knows where to buy just the odd plug that would be good to know.

 

[Bogo]

A friend uses a automatic 50 amp battery charger with his 1000W inverter generator. Maybe to high for most starting batteries, but it cuts the charging time for his RV house bank which can easily accept 50 amps. He also figured out how much fuel is needed per hour when charging. He then only puts in enough fuel for X hours and lets it run out.