# Charging Battery With Generator



## Jewellfamily

Looking for some feedback on charging the RV battery with a generator after running it all the way down:

1: What have you found works better: Hooking the genny up to the 30Amp RV receptacle and letting the converter charge the battery or using the dedicated battery charge feature on the genny directly to the battery?

2: How long do you typically have to let the genny run to get a full charge if you run the battery all the way down?

Obviously everyones systems are a little different but would like your input. I currently have 1 12v Marine battery, but will be upgrading to 2 6v deep cycles in a few weeks. Was using a 2000W yamaha inverter generator on a 312BH.

Got the 1st trip of the season in this weekend by the way!!!


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## Insomniak

The converter in the Outback will provide far more charging power than directly from a generator, even if you have the WFCO model. My Honda 3000 watt generator only has a 12 amp battery charger, but my PD9260 converter in the Outback can produce up to 60 DC amps. With the PD9260 going full-blast, I can get batteries to 90% or more in a couple of hours.


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## CamperAndy

The 12 vdc output from the generator is a last resort for charging batteries. You use that to charge the car battery if you are miles from anywhere and you ran it down running the trucks radio while fishing or something. To charge the trailer battery use the converter in the trailer.

How long it takes depends on many things but it can take many hours to fully recharge a dead battery.


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## KTMRacer

while the WFCO isn't known as a great charger (often won't go into the boost mode), it's still way better than the generator charger output. And if the battery is truely well discharged (down to 20-30%) then the WFCO may go into boost mode with close to 50A. Even if it doesn't, it will be in the 20A or so range, just will take longer to charge. How long to charge depends on the charger and the battery bank. A single 12V 80AH battery, discharged to 50% is a 2-3 job or so to charge with even the WFCO not in boost mode. a pair of Golf Cart 6V, discharged to 20-30% of capacity is longer. I have a pair of Trojan T125's. When discharged to 30% of capacity, I have a PD 60A and PD 55A running in parallel. starts with 90-100A charging current. takes about 2 hours to get to 80% SOC, another two hours to close to 100%

once you have a pair of 6V batteries, you have a better chance of having the WFCO go into boost mode. However, if it doesn't it is still better than the generator, but if the batteries are discharged to 50% or less of capacity, it's going to take a LONG time to get them charged if the WFCO doesn't go into boost mode, like maybe 8 hours or more from my experience.


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## Jewellfamily

Thanks guys, I figured the converter was the way to go. I was only letting the generator run about 90 minutes or so. The battery gage said it was full in that time, but could tell it didnt have the same capacity as it normally was when full.

Had a good time on the 1st trip of the year!!


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## KTMRacer

Jewellfamily said:


> Thanks guys, I figured the converter was the way to go. I was only letting the generator run about 90 minutes or so. The battery gage said it was full in that time, but could tell it didnt have the same capacity as it normally was when full.
> 
> Had a good time on the 1st trip of the year!!


unfortunetly, the battery gauge borders on useless. I have a trimetric setup which measures the AH drawn from the battery and then the charging AH to give a better indication of actual battery condition. When my two golf cart batteries are at about 70% of capacity, the battery "gauge" says I'm fully charged, it has to get below 50% state of charge before it goes from 3 lights to two.


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## Insomniak

Just like the holding tank gauges, with batteries there's a lot of space between "low", "medium", and "full".


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## Beachnut

I have 2 Honda 2000 gen's that I bought just after the trailer purchase. One 2000 is the "companion" to link the 2 gens together to run the A/C while the other 2000 gen is the usual one, that has a 12vdc battery charging plug on it. I hooked that 12vdc charger up to the batteries, that were still hooked up to the trailer, which was also plugged into the single 2000 gen. through the trailer 30 amp A/C cord. I was a newbie and thought the 12vdc out of the gen would charge those trailer batteries even faster, along with the A/C going to the trailer charger. *NOOOOooooo,,,* NOT a good idea!







Something popped, and the A/C on the gen was gone! (Good think I had the 2nd gen with us or the trip would have been Ka-put). The Gen was new, so they fixed it for free, but told me to NEVER hook up the gen to the batteries through two circuits at one time as damage could result. (Duh)







Something about phase change / conflict / the trailer charger surging the gen charger... So, just let the trailer do the charging. Even for charging extra non trailer batteries, it is much better to plug in a "real" charger into the generator and let it work off the A/C side, than try and use that DC "charger" coming off the gen as it is a (SLOW), low amperage charge.

Beachnut


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## Mark W

Hello to All:

I've been trying to find any previous posts that have detailed descriptions / pictures of changing out the OEM WFCO Converter and installing a PD9260 Power Converter.

I've got an Outback 250RS and have never really done much electrically before, so even though I now have the PD9260, I'm hoping for some good encouragement and descriptive instructions on how to switch out the WFCO with the new PD9260.

My apologies if this has been discussed in great detail before--if so, does anyone have the link to this?

Thanks in advance for any and all advice that can be given to this hesitant, yet willingly intrepid Outback owner.

--Mark W.


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## KTMRacer

Insomniak said:


> The converter in the Outback will provide far more charging power than directly from a generator, even if you have the WFCO model. My Honda 3000 watt generator only has a 12 amp battery charger, but my PD9260 converter in the Outback can produce up to 60 DC amps. With the PD9260 going full-blast, I can get batteries to 90% or more in a couple of hours.


Over the last two weekends, I've helped 4 people with charging problems. All 4 had WFCO converters along with the typical to small and to long wires between the converter and battery. End result, the WFCO never got above 13.6 V and around 12-15A max current even into a battery that was well below 50%.Tnen the output voltage was down around 13V. So, yes, it's better than the honda output but not by much. Running the generators all day long wouldn't even come close to bringing the batteries up to near full charge, in fact you can not get deep discharge/marine batteries to full charge with a 13.6V output limit.

conclusion, based on these 4 cases, my similar case and two others I also helped with last year, IF you dry camp and want anything close to decent charging, you need to replace the wfco with a pd or iota converter that will get you 40-80 amps (or even well above 100A, useful for big battery banks) and 14.6V to the batteries. OR buy a Black and Decker Vector 40A charger and run that off the generator and connect it directly to the batteries.

And even if you don't dry camp, the WFCO is going to reduce your batteries life. Not being able to get it to go to 14.6ish volts for part of the charging cycle, you will never meet the charging requirements for virtually all flooded cell deep discharge or marine battery manufactureres. And not bringing the battery to 100% charge leads to a host of problems that reduce battery life and capacity.

BTW starting batteries are much different in charging profile requirements, but you don't want to use them for RV use anyway.


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## ED_RN

Just read a very detailed article about this issue before I bought a new charger. According to the expert the problem with the D/C ouput, at least on the Honda 2000's, is they only put out 12 volts. If the article was right to correctly and fully charge a 12 volt battery requires 14 or 15 volts along with the correct amperage. I looked at the specs for the EU2000 and they show the output as 12 volts,8 amps.


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