[Colt Carson]

I have a Honda EU3000is that is a little over 10 years old. Many years ago when the original battery died, I never replaced it and just used the pull rope to start the generator. I taped the battery wires so they wouldn’t touch anything with the battery gone. I read another post here of someone's (Generac) electronics getting fried by running the generator with the battery removed. I’m wondering if I should purchase a new battery to install. So far it has worked fine when I do the monthly test runs with load applied. My generator has no bluetooth or CO detector, just the low oil shutdown.

 

[OrlyP]

I'd put in a new battery and connect it to a smart/float charger. Whether or not the absence of the battery is bad or not, the convenience of having one so you can use the starter motor is justification enough.

It appears that on some generators, the battery serves as a pseudo filter capacitor and voltage regulator. Without the battery, DC voltage across the open terminals can get as high as 18-24V. If the generator has logic circuits powered by this DC source, the high voltage can potentially fry them. With the battery connected and absorbing the unregulated DC, you'll be looking at a comfortable 13-15V, which is generally safe for whatever the generator logic is using it for. This is the case with modern vehicles.... you could kill the many computers in your car if you run the engine without the battery.

 

[Colt Carson]

I'd put in a new battery and connect it to a smart/float charger. Whether or not the absence of the battery is bad or not, the convenience of having one so you can use the starter motor is justification enough.

It appears that on some generators, the battery serves as a pseudo filter capacitor and voltage regulator. Without the battery, DC voltage across the open terminals can get as high as 18-24V. If the generator has logic circuits powered by this DC source, the high voltage can potentially fry them. With the battery connected and absorbing the unregulated DC, you'll be looking at a comfortable 13-15V, which is generally safe for whatever the generator logic is using it for. This is the case with modern vehicles.... you could kill the many computers in your car if you run the engine without the battery.

I’m normally good about reading owner's manuals, I would hope if the absence of a battery were a problem it would have been mentioned in the owner’s manual. I think to be safe I’ll go ahead and replace the battery. Does anyone have a good link to a short adapter so I can charge the battery without opening up the generator?

 

[OrlyP]

I’m normally good about reading owner's manuals, I would hope if the absence of a battery were a problem it would have been mentioned in the owner’s manual. I think to be safe I’ll go ahead and replace the battery. Does anyone have a good link to a short adapter so I can charge the battery without opening up the generator?

Most battery maintainers includes the pigtail connector in the package. One end are eye terminal lugs while the other end is an SAE connector. You just screw on the eye terminal lugs to the (+) and (-) posts on the battery and the SAE connects to the charger.

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[Airstreamer67]

Many years ago, I bought a new Honda EX4500 generator that came with a small factory battery since it is electric start only. Because the generator is rarely used and so is usually in storage, I removed the small factory battery when I bought the unit and wired extended positive-negative cables out the side of the genset for quick hookup to a 12VDC battery I use for other purposes in my shop. So, when I need the Honda, I simply hook the wires to a battery and off we go.

One time, after starting the genset with a battery, I removed the battery to use if for something else, but the engine died after several minutes. I reconnected the battery and it started right up and ran well. So, this genset seems to need having a battery in the circuit to operate properly.

 

[Colt Carson]

I believe some portable generators use their battery to supplement their surge capability. I don’t think my EU3000 works that way.

 

[OrlyP]

I believe some portable generators use their battery to supplement their surge capability. I don’t think my EU3000 works that way.

It may have more to do with the generator engine control electronics needing clean 12VDC that a battery affords.

 

[tabora]

I believe some portable generators use their battery to supplement their surge capability.

I have never heard of that, ever...

 

[Colt Carson]

I have never heard of that, ever...

It was something I read years ago somewhere online, I believe in the features of some generator. I tried to search for something on it, but too much irrelevant info kept popping up.

 

[OrlyP]

I have a battery on my generator for obvious reasons (starting) but I have disconnected the circuit that allows the engine to charge it. The charging circuit is just from the '12V' charging coil in the engine with a simple rectifier. The reason I disconnected it was because it was giving out 15-16V DC with the battery connected. That will easily overcharge the battery and reduce its lifespan. With the factory charging disconnected, I use an outboard smart charger, powered automatically from the utility or generator power (through my home ATS).

I have never heard of that, ever...

In the context of starter batteries in generators powered by internal combustion engines, providing assistance to the high voltage side (120/240V) is NOT a thing.

In automobiles, it's a thing.

 

[Winnipegmike]

I don't know anything about this subject, but this Yamaha advertisment says they do use the starting battery for surge power:

• Yamaha Boost Technology® (YBT) (EF3000iSEB only)

Boosts output by adding battery voltage to alternator when needed. The Boost Control Unit (BCU) senses when extra power is needed and boosts output for up to 10 seconds, giving air conditioners, power tools, and other equipment the extra boost of power they may need to start quickly and efficiently.

 

[GenKnot]

this Yamaha advertisment says they do use the starting battery for surge power:

That's really interesting. They may be the only one out there doing this.

 

[Colt Carson]

I don't know anything about this subject, but this Yamaha advertisment says they do use the starting battery for surge power:

• Yamaha Boost Technology® (YBT) (EF3000iSEB only)

Boosts output by adding battery voltage to alternator when needed. The Boost Control Unit (BCU) senses when extra power is needed and boosts output for up to 10 seconds, giving air conditioners, power tools, and other equipment the extra boost of power they may need to start quickly and efficiently.

Thank you, Sir! It was bugging me that I couldn’t remember where I had read that information. I was reading this generator's online manual and noticed something curious… it seems to use a special battery. It is equipped with a "valve regulated lead acid battery", which requires a constant-voltage battery charger. It says using a conventional battery charger to maintain the battery can damage it.

 

[tabora]

I don't know anything about this subject, but this Yamaha advertisment says they do use the starting battery for surge power:

• Yamaha Boost Technology® (YBT) (EF3000iSEB only)

Boosts output by adding battery voltage to alternator when needed. The Boost Control Unit (BCU) senses when extra power is needed and boosts output for up to 10 seconds, giving air conditioners, power tools, and other equipment the extra boost of power they may need to start quickly and efficiently.

Amazing what you can do with an inverter generator, at least that particular one... I wonder why that's the only model it's used on?

 

[iowagold]

maybe use a larger start battery on that yamaha unit?
you might have a better start power with less surge voltage dip...

yes you can do lots of things if the design in the generator inverter will work with the 12 volt as an energy source.

you would be better off using an stand alone inverter system for home back up..
and use at least 48 volts on the battery system or more!
the higher the voltage on the power source for the inverter the better the conversion..
that is why honda inverter gens use 3 Phase and at least 200 volts to 400 volts depending on the model of the eu series of gen set..

 

[OrlyP]

Well I'll be.... that's an unusual architecture. In fact, it's only available on that specific model ("B" in the model code) and that's from 8 years ago. It's an oddball feature not available in any other model, AFAIK.

At some point, the Boost feature was replaced with a button you can press so the engine revs for 60 seconds, giving it ample power reserve to start heavy loads.

 

[tabora]

It's an oddball feature not available in any other model, AFAIK.

Yup... There must have been issues or some kind of downside.

Yamaha 3000 Watt Inverter Generator with Boost Technology (+500 Watts)
Model # EF3000iSEB

This item has been discontinued by the manufacturer

 

[Bobcat]

Yup... There must have been issues or some kind of downside.

Yamaha 3000 Watt Inverter Generator with Boost Technology (+500 Watts)
Model # EF3000iSEB

This item has been discontinued by the manufacturer

It was temporarily discontinued for CO update.
Yamahagenerators.com $2573.10
Manufactured in Japan

 

[GenKnot]

It was temporarily discontinued for CO update.

Yup. It is now being delivered in the CO version as of August 2022. The boost technology adds 500W for 10 seconds.

 

[tabora]

It was temporarily discontinued for CO update.

Yup. It is now being delivered in the CO version as of August 2022. The boost technology adds 500W for 10 seconds.

Glad it's back! That's a pretty cool use of available starting battery power.