Yamaha EF2000is didn't charge batteries

[RPVEd]

Greetings All. First question I have posted.
The question is: Why didn't my Yamaha EF2000is charge my trailer batteries?
First trip with no hookups. Fourth trip overall.

I tried to directly charge the OEM batteries in my trailer from a single generator after I determined that I had been sold a Yamaha twin tech cable instead of a Yamaha parallel power cable. Yamaha supplies a DC cable that allows you to directly connect to battery posts. After connecting up and starting the gen, I never got any boost in the voltage of the batteries. Any ideas why not? Was there a correct way to do this? Batteries fully charged on drive back to storage.

I have a 50 to 30 dogbone (that I was going to use to connect to the parallel power outlet if that had fit). Would a 30 to 15 have allowed me to add that and plug into the 15 outlet on one of the gens to power the trailer through the shore power inlet?

2015 27'FB Signature (with two A/Cs)

Thank you,
Ed

[Foiled Again]

I'll never claim to be any kind of expert about battery charging, but I've always been uneasy (scared spitless) about charging batteries directly from my genny. I've heard stories about batteries overcharging and exploding, so in an excess of caution I've used a conventional battery charger plugged into the generator on the few occasions where it was needed.

Bad batteries? If your trailer sat on the dealer lot for 9 months before you bought it, and people went in and out and left lights on, etc.... you could have batteries that were close to gone before you ever got the unit. Check the water level in each cell to make sure they aren't sulfated. Then try a conventional charger. The problem might not be the generator.

Paula

[AWCHIEF]

Did you measure the output of your generator to insure proper functioning?

[RPVEd]

Hi Paula, thanks so much for the reply. Barbs and I have enjoyed your highly entertaining posts since we joined. Just thought it was weird that the batteries fully charged on the tow to storage but wouldn't charge off the built in DC battery charging system of the Yamaha. The batteries themselves lasted OK for the three days of dry camping but I was disappointed that I could not charge them up off the generators.

[RPVEd]

Michael, great question that leads to another question. I'm fairly inept at testing electronics. Would you plug an AC device into the AC outlet on the generator to see if it operates? How would you go about confirming the gens are operating properly? I was just so happy that I was able to oil and gas them up and get both started successfully. Thanks,
Ed

[AWCHIEF]

Use a volt meter.

[RPVEd]

Thank you Michael.

[lewster]

Your generator's 12VDC direct is probably the WORST way to attempt to charge a deep cycle battery. Low level constant voltage will NOT make your batteries very happy and will also have a high probability of damage.

First thing to do is have your batteries checked. Simply because they accept a charge that LOOKS like full doesn't mean that they are retaining that charge.

In addition, if you have the original converter that Airstream provides, there is a very good chance that your batteries have been fried by that device's single voltage charging.

Sounds like you might be in the market for a new 3-stage 'smart' converter and a new set of batteries.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[overlander63]

And to add to Lew's post, the generator probably only has a 5-7 amp DC output. At that rate, it would take over 20 hours to charge a single battery. IF it didn't get ruined in the process.
I've used that DC output on my Honda exactly twice, to put enough juice into a dead car battery so it would start, and drive to go buy a new battery. I don't think I'd want to try more than that.

[RPVEd]

Thank you Lew. Thank you overlander63. I've been operating under the presumption that the two inverter generators would supply some AC power, hopefully enough to run one air conditioner, and recharge the batteries. I'm amazed that in their native DC mode, before inverting to AC, they couldn't even charge the batteries.
I will be checking the current status of my batteries well before our next trip in anticipation of trouble.
The answer to my question is: I shouldn't have expected the Yamaha EF2000is to charge my batteries.
Thanks all.

[Loden]

That generator has plenty of output to charge your batteries, just not on a 12vdc direct hookup! You can either power the AS elect system with 110vac and let the internal converter/regulator do the job, or get a good battery charger, hood the 12vdc cables to the batteries and plug it into the generator. Either way you need a regulator between the generator and the batteries. If you charge them directly with a battery charger, you will need to disconnect them from the trailer before charging.

Since they charged up on the way back from camping, I suspect the internal regulator/converter in the AS shunted the excess power away from the batteries to keep them from being damaged.

[lewster]

Originally Posted by Loden

That generator has plenty of output to charge your batteries, just not on a 12vdc direct hookup! You can either power the AS elect system with 110vac and let the internal converter/regulator do the job, or get a good battery charger, hood the 12vdc cables to the batteries and plug it into the generator. Either way you need a regulator between the generator and the batteries. If you charge them directly with a battery charger, you will need to disconnect them from the trailer before charging.

Since they charged up on the way back from camping, I suspect the internal regulator/converter in the AS shunted the excess power away from the batteries to keep them from being damaged.

............'internal regulator'????????

Unless Airstream has dramatically changed the way they install their Parallax converters, the ONLY device that will stop the converter from improperly under/over charging your batteries when 120VAC is available is the BATTERY DISCONNECT SWITCH placed in 'STORE' mode. There are no other devices that perform this function, unless Airstream has begun to install a 'smart' 3-stage converter/charger. As of the 2105 models.....they have NOT.

ANY single voltage DC power source like a generator's DC output connection or the internal Parallax converter/charger will more likely do damage to the batteries as neither is capable of producing the required voltage/current necessary during the various charging stages for proper battery charging.

[ROBERTSUNRUS]

Hi, I'm not sure how you had your generator hooked up, but my Yamaha 2400 says that you can't use the 120 volt system and the 12 volt system at the same time. Best to connect your generator directly to your shore power cord.

[Loden]

I emphatically agree! Outside of an emergency of some kind, attach your regular shore-power cable to the generator. That will charge the batteries using the internal regulator.

[lewster]

Originally Posted by Loden

I emphatically agree! Outside of an emergency of some kind, attach your regular shore-power cable to the generator. That will charge the batteries using the internal regulator.

Guess you didn't read my post above?


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[RPVEd]

Thank all of you very much! I had intended to connect two EF2000is's to the 50amp umbilical with a 30 to 50 dogleg. I got the wrong parallel cable socket for my 30 amp plug and had to abandone that plan. Watch out for that when getting the parallel cable kit. Mine was sold to me when I got the two gens. Not being familiar with generators, my initial concern was could I get them started. Learned somethings about draining and drying out carburetors and use or non use of a chock. Got that under control and went camping. I also did not have a 30 to 15 dogbone. Will be getting one of those. We were using battery power exclusively and I was hoping the DC direct would extend the charge. Batteries worked fine for the three day trip but could not boost the charge with the generator. Now I understand why. It would have been interesting to try out the 50 / 30 / 15 combo to see how effective that would have been. Have purchased the correct parallel cable kit.