# How Long Does It Take To Recharge A 12 Volt Battery Using A 1000 Watt Generator?



## vagabond (Jan 5, 2007)

We just returned from our first dry camping experience with our 08' 21RS. Our 12 volt battery drained within the first 30 hrs or so. We used the lights and water pump plus hidden uses associated with refrigerator running on gas-- climate control turned off; detectors and the like. We learned about the propane detector the hard way -- it went off due to the low battery. I hooked up to my truck and ran it for 20 minutes to get some life back(minimally effective). Having just read some of the threads on all this it seems that our experience is fairly typical.

So I have decided to get a generator (honda, yamaha or Kipor). Our primary objective is to recharge the 12 volt deep cycle battery. We can live without the AC & microwave, but really want to be able to use the lights and water pump (we may switch out some of the light bulbs for lower watt versions). My question: How long will I have to run a 1000 watt generator to recharge a drained 12 volt deep cycle battery?

Life is so much better with the all the help provided by outbackers.









Rick


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## albion (Jul 17, 2007)

Sorry, I don't have the answer to your question. However, IMO, you would be better served to upgrade your battery bank. We are a family of four and we dry camp for three to four days at a time. Adding a second battery or better changing to 6 volts would be less expensive and if you don't care about the A/C you could get an inverter that would allow you to use some 110v items.

Good luck!


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## beachbum (Nov 27, 2006)

I am sorry I cannot answer your question directly about the charging time. But, DW and I dry camp often and we have a 2 6V battery set up. To give an example of their usefulness, we just returned from a 3 night 4 day beach trip. Used lights, ran water pump, watched a movie (DVD) every night and ran a 12 v fan at night. Battery indicator never went below 2/3. Very happy with that performance. It's not that difficult or expensive to make the change.
david


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## Insomniak (Jul 7, 2006)

It kinda depends on how "drained" your battery(s) are and what shape they're in. The first thing I've done with our two Outbacks is replace the single crummy Interstate battery they throw in for free. We do a fair amount of dry camping, and I have two group 27 batteries that I got at Costco (Johnson Controls is the mfr).

It's really hard for us to conserve with two little kids, but on my own I can go several days without having to recharge. When the batteries are really low (less than 11.7 volts), the Honda 1000 watt generator and PD9260 converter combo will hit the batteries with up to 60 amps of current. Within a couple of hours, the batteries will usually be back up to about 80-90%. From there, the converter backs down and it can take another 12-18 hours to get the batteries fully charged unless I put it back into "bulk" mode. On average, I'd say running the generator a couple house a day maximum will keep you in good shape.


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## vagabond (Jan 5, 2007)

Thanks for the responses. I think I'll try to find a good group 27 battery and see how that works (switching it out with the one I have). If that isn't enough, I'll give in and get a generator.

Rick


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## Insomniak (Jul 7, 2006)

Keep in mind that a group 27 battery won't fit in the space where your current battery lives. Cut a piece of 2x6 (or 2x8, I forget which) to fill in the battery tray and put the battery on top of the wood. You can mount some brackets on the wood to help keep the battery in place, and hold the whole thing in place with tie-down straps. I have two group 27 batteries that give us 230 amp-hours, or you can go over to the 6 volt camp which would give you about the same capacity (but reportedly much more longevity....







)


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## tripphammer (Oct 3, 2006)

The wattage of the generator (or inverter in the case of most Hondas) does not allow you to necessarily tell you how fast the battery will be charged. There are far more factors to be considered. Does the generator/inverter have a charging system and if so what is the charging rate (most likely in amps). If not, what size battery charger is being used and what is it's charging amperage. Then of course as mentioned above, it also depends on how low the battery has been drawn before being charged. Also, you need to know what the amperage capacity of the battery is and what is it's cycle. I am no engineer, but I do know that is there are some websites that can help. Is there anyone out there that can provide some links!
Take Care,
Tripp


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## jt-mt-21rs (Jun 17, 2006)

I have an 1800 watt generator that I used when I'm at the racetrack to keep the battery charged and topped up. I let it run for a couple of hours during they day and it seems to keep up ok. Once it's drained I would guess at least 3-4 hours. I just bought a 2800 and it charges in a fraction of that time. I have my doubts that a 1000 watt would do much unless you can let it run for a long time. I can't explain it properly but the lower wattage generators just don't generate a lot of amperage so the charging rate is very slow.

I did do some dry camping a couple of weekends ago (without a generator) and the battery lasted about 30 hours. I brought an extra battery that I use for the winch on my car trailer and used it for the rest of the weekend. I haven't had a chance to compare it to the Interstate that came with the OB. I was kind of surprised it died after only 30 hours to tell you the truth. I expected longer life.

The other thing you could do is buy another 12V deep cycle battery and get the adapters so you can switch it with the battery in your tow vehicle. That way you charge it during a day trip or drive to the beach.

Good luck with your choice.


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## Sluggo54 (Jun 15, 2005)

This is a two-parter, Rick. First, a battery upgrade will help immensely. A Grp 27 won't cut it; it is minimally better than a Grp 24. A couple of T-105's or better will kick up the battery life to "useful".

As for how long to recharge a battery - depends on the smart charger you plug into that generator. I have this one:

http://tinyurl.com/25p75e

With the batteries at 1/3, it will take about three hours to pump'em up.

Sluggo


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## vagabond (Jan 5, 2007)

Thanks again for all the suggestions. I ended up installing two Trojan T105 6volts in series. Yesterday I tested it out and was impressed by the power of this set up. I ran 4 lights (2 bulbs each-- I think they are 18w per bulb) and the radio for 10 hours straight. I also used the water pump for about 6 minutes. This comes close to my normal usage for 2-3 nights of dry camping (I did not run the refrigerator so that will be an extra draw) After all this I still had 12.3 volts on the batteries (2/3rds on TT indicator). I plan to carry the 12 volt interstate battery that came with the Outback as a backup. That might just be enough so I won't have to buy a generator after all.

One question remaining for folks who use the 6 volt battery set up. Do you make a point to recharge the batteries using a 3 or 4 stage recharger (e.g., smart charger) once you get home or is plugging in the camper for a while to let the built in TT converter do the recharging enough? I keep my TT at home so plugging is no problem.

Rick


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## Sluggo54 (Jun 15, 2005)

vagabond said:


> One question remaining for folks who use the 6 volt battery set up. Do you make a point to recharge the batteries using a 3 or 4 stage recharger (e.g., smart charger) once you get home or is plugging in the camper for a while to let the built in TT converter do the recharging enough?
> Rick


Again, it depends. Mostly on how smart your converter charger is. Many will overcharge if left on long-term. Mine doesn't, but it does tend to undercharge just a bit. That's preferable, to me. We are heading out Friday; I will hook up the charger before we go. Normal travel will keep them up if we are boondocking and moving every four or five days. We are light users, though, I haven't yet made the effort to hook up the TV and satellite box so I can run off an inverter. I have to pull the TV, a two-man job, to do that.

Sluggo


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## beachbum (Nov 27, 2006)

I have a Vector 3 stage charger I use to fully charge my batteries. Once they are "full", I use the TT on-board charger to top off a day or 2 before we leave. When we return, I use the Vector again to get a full charge and then we are ready for the next trip.
david


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## tripphammer (Oct 3, 2006)

Great choices Vagabond !!!!!

However, is there another model of refrigerator for an Outback than I am aware of? I thought all are either 110 VAC or Propane... not 12VDC.









Take Care,

Tripp


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