How long to recharge battery from shorepower?

[rbpru]

The few times I have camped without electricity I have left before the battery was exhausted (two days) or I jumped it from the truck for 15 to 20 minutes to get through a third day and into the fourth.

Of course on the drive home the battery was charged though the 7 pin plug.

My question is, if I bought a small 700 watt generator or could plug into shore power for a short period of time, how long does it take my three stage WFCO charger to bring the battery back to full charge?

I see 45 watt solar chargers that could be used also.

[esox07]

Soundguy: thanks for that explanation. That is something I did not know. If I ever get seriously into dry camping, that is something I will pursue.

[SoundGuy]

esox07 wrote:
I assume the OP is running the fridge on propane and I understand that the fridge still needs battery power to control things, but what does that mod do exactly to reduce battery power consumption by the fridge?

The climate control system is a 12 vdc heating element placed around the freezer compartment to help minimize the build up of frost. Obviously when running on shore power you don't really care how much this heating element is drawing but likewise as obvious when running on battery power alone whatever power that heating element requires is drawing down the battery. Since this climate control heater is just a convenience and not critical to the operation of the fridge it therefore only makes sense to turn it off when running on battery.

[esox07]

I assume the OP is running the fridge on propane and I understand that the fridge still needs battery power to control things, but what does that mod do exactly to reduce battery power consumption by the fridge?

[SoundGuy]

rbpru wrote:
At this point I think I will reduce the phantom loads by turning off the antenna booster and disconnecting the radio/CD player.

Presumably you've already switched all your incandescent bulbs to LEDs but do you remember to disable your fridge climate control heater when running on battery power? If your particular fridge isn't equipped with such a switch it's good idea to add one yourself as you're otherwise unnecessarily drawing down your battery reserve. 😉

My climate control switch mod is detailed here.

[esox07]

Yah, definitely turn off all the devices that you are not using. With just battery power, the antenna amplifier isn't doing you an good anyway unless you are running a TV off battery power as well.

I agree with the "fast charge" statement. you can put some power back into a battery fairly fast, but it is very hard on a battery and you will never get a full charge that way. Batteries don't do well in a partially discharged state for prolonged periods. It is a leading cause of battery failure. I always use a charger/maintainer which only drops 1.5 to 2amps into the battery unless the battery is under half charge, then I will put it on the regular charger for few hours and switch to the charger/maintainer after that to get it fully topped off. I have a 6 year old cheapo battery in my riding mower that starts my mower like the day I bought it. I get done mowing and put it right back on the charger/maintainer. It sits in the garage between mowings and all winter long. My RV battery is three years old but really doesn't get a lot of use. but the original only lasted two years before I replaced it and started using the charger maintainer between uses. The one that I have also does a "desulfication" on the battery which is key.
https://www.amazon.com/BatteryMINDer-1510-Battery-Charger/dp/B00Q3CM2QY


The second battery sounds like your cheapest and least cumbersome solution. Good luck and have a great summer camping.

[rbpru]

Wow, when it gets into the details, it is amazing how much power it takes to truly recharge a battery.

Most importantly there is no such thing as a fast charge. I was hoping for an hour or less off a small generator.

At this point I think I will reduce the phantom loads by turning off the antenna booster and disconnecting the radio/CD player. The remainder must stay connected. I also have a second battery I can change out when the first goes down.

Thanks for the info.

[SoundGuy]

Dirtpig wrote:
I think you should get 2 new group 31 batteries or 2 6volts and replace your old probably worn out/abused battery. And go for something like this for charging instead of a 45watt panel Renogy 100watt suitcase solar

We camp as does the OP, most times on electric sites, but seem to lose power frequently enough each season that I added a 1000 watt PSW inverter to our trailer so we could still use our coffee maker, toaster, a couple of fans, etc. My single G27 is sufficient for most but does struggle a bit with the toaster load so I cut up an old 4 gauge booster cable set, wired it directly to the truck's battery, and (with the truck running) use it to load support the G27 when it's under heavy load. Without it the toaster load would drop supply voltage well into the 11s, with load support voltage drop is minimal, a non-issue. :B

For periodic use load support works just fine and in emergency cases could be used to push just enough back into the trailer battery to keep it going a little bit longer. However, if we intended to actually dry camp any more frequently I'd choose Dirtpig's option - upgrade to 2 G31s in parallel or 2 GC-2s in series, choice depending on what would fit best on the trailer tongue - and invest in a folding portable 100 watt suitcase solar panel that can be set on the campsite to avoid shade and be moved during the day to follow the sun.

Obviously a genset offers the assurance of effective recharging during cloudy conditions but there's no getting away from related issues - noise, fumes, the need to carry gas, the need to heft it in & out of the truck, storage & maintenance when it's not in use, concern over theft, etc. I've owned 2 Honda EU2000i gensets and in time became so fed up with all these issues I more often than not would leave them home in the workshop. The final straw came in the fall of 2015 when an unexpected freak snowstorm knocked out campground power for almost the entire weekend, and where was my EU2000i? ... back home in the workshop! :S

Bottom line - either genset or solar can be an effective solution for many but based on my genset experience a portable folding suitcase style solar panel sure seems to be a solution I'd be much more likely to always have on hand when we're camping and actually use. 🙂

[Dirtpig]

I think you should get 2 new group 31 batteries or 2 6volts and replace your old probably worn out/abused battery. And go for something like this for charging instead of a 45watt panel Renogy 100watt suitcase solar

You would never have a problem with power again. I personally think its easier to pack around the solar panel then the generator and gas.

Also no noise, and you look cooler.

I have both solar and generator, i only use generator in months of october-feb.

[rexlion]

If you are running the battery down to where it's almost out of juice, you are damaging your battery (shortening its life and reducing its ability to store as much energy). Lead acid batts like to be kept above 12.1V or thereabout, which is about one-half discharged; below that they start to sulfate. Got a volt meter? If so, take it camping and check your TT battery once in a while. You might be surprised.

Do not expect the battery to get anywhere near fully recharged on the drive home. That long, thin gauge charge line can't feed many amps back to your TT. Plugging the TT into shore power at home will do loads more charging than your tow vehicle.

For your level of power usage, I think a 100W solar panel would keep you going for many days... provided you have sun. Or get a generator. Or get a pair of golf cart batteries, which have heavier plates and can stand up to abuse, plus they'd give you more capacity.

[ktmrfs]

with the WFCO charger figure at least 24 hours for EACH battery you have, unless you are THE lucky guy, the WFCO will only charge at about 13.6 V or less and a current of around 15A. and at 13.6 V it will actually NEVER get a battery fully charged.

Now with a PD or simlar real 3 stage charger you can get to 80 percent in a few hours.

[esox07]

I have never dry camped for an extended period. But I found a nice park about 30 miles away that only charges $5 a night and I might go park for a few days to a week. It is right on a river and is very quiet and peaceful. I have my trailer battery and I could bring along the trolling motor battery as well. It is in a Minn Kota Power Center case which makes that easy. But, I will bring the genny as well. Tough to go without some coffee and maybe some TV and A/C.

[Sillybugs2]

We have two batteries and a 2K honda gennie. Can use gennie to charge batteries every two days for a couple hours and we are good. Water fill.up issues before power. We camp similar to you in using it like fancy tent when off power.

[time2roll]

I recommend two batteries minimum for off-grid camping. Might be all you need.

Then you need to decide if you want to replace the converter and get a generator. Need to maintain it, gas it, and listen to it.

Or go solar if you get any sun. I would almost always recommend solar first.

[esox07]

Sounds like a second battery might be your best solution. That doubles your time without the need for any heroics. You could wire them both in to your system or just swap them when necessary. Otherwise, I would look at a generator. Certainly, you won't be able to run the genny for 30 hours to fully top off a battery, but if you run it for 3 or 4 hours with a battery charger hooked up that is dropping 10 or 12 amps into the battery, you will get enough charge to keep it going quite a bit longer. Also, with the genny running, it is a good time to use the power for those other things, like a pot of coffee or maybe a couple hours of TV or maybe run the A/C and cool down the camper for the evening. That would be a way to really open up some other camping situations.
Of course, you need to get a generator big enough for whatever you plan on running.
I have a Boliy inverter generator that is rated at 3000W continuous. That is enough to run the A/C, brew a pot of coffee all while watching Jerry Springer with power to spare for the battery charger.