Charging Spare battery on sidetrips

[fubu]

So I understand charging an RV battery while the RV is connected to the tow vehicle, that's not tough.
What I'm wondering is after a few days of dry camping, the battery will become drained and require charging. I don't have a generator, I don't currently have solar charging. I do have another battery. My thought was that I could swap a drained battery for a charged one, simple enough, but now how do I charge the drained battery? I was thinking, since I have side trips planned that will require some driving time without dragging the trailer, I could charge a battery while driving. I just don't know how I would do that. It seems like a common issue, I was just unable to properly frame a google search that answered "without the trailer". So here I am 

For the record, TV = '09 f150, RV = '13 Jayco x19h. The plan is for fridge use only, although I understand there is parasitic drain throughout the RV, I will be making every effort to reduce all that, but I expect to run out of battery before the end of 9 days of dry camping.

I was thinking some kind of jury-rigged 7-pin plug connected to charging cables and plugged in with the battery in the bed of the truck, but that seems unlikely to be a permanent solution, nor the right one.
So, charging a spare battery while driving around without the RV?

Thanks!

 

[kdbgoat]

How about a solar charger?

 

[schoolsout2]

Check the farm supply stores for a solar charger, they MAY put out enough for your needs.  I used one on my boat to keep it topped off between uses.

 

[kdbgoat]

Or maybe a small inverter type generator. Northern Tool sells Powerhorse brand that actually has good ratings, or you can step up to Yamaha, Honda, or Generac.

http://www.northerntool.com/shop/tools/product_200623983_200623983

http://www.generac.com/iq2000

https://www.yamahamotorsports.com/generator/models/ef2000isv2

http://powerequipment.honda.com/generators/models/eu2000i

 

[Gary RV_Wizard]

If there is some place on the tow vehicle you can put the spare battery, it could be hooked into the electrical system and get charged as you drive. Somethign as simply as jumper cables to the vehicles main battery would do the trick, if there is a place close enough for another battery. Hard to make a suggestion when you provided no info about the tow vehicle or the size of the spare battery.

However, the fridge along won't deplete the battery much at all, nor will the water pump. They simply don't draw much power. Lighting is a biggie, though, and maybe you will have some other devices (like a 12vdc phone charger, a small inverter, or???).

Also, you don't have to swap batteries - just connect the two in parallel. If there isn't room in the battery compartment of the RV, the second battery can sit on the ground nearby and connect with standard car-type jumper cables.

 

[judway]

You can buy a small 700 Watt gasoline generator at Harbor Freight for $87.79 this weekend if you have a store close by. This should give you a charging rate of about 50 Amps. I don't know how noisy it might be.

They also have a 45 Watt solar collector on sale this weekend for $119.99. Good for about 3 Amps charging rate. No noise.

 

[fubu]

Thanks for the replies!
We've always camped without any electricity - battery flashlights and lanterns, glow sticks as night-lights for the kids, and propane BBQ and stove for cooking. The fridge on the old tent trailer never really worked well, so it got used as basic storage. A dedicated dry ice cooler was our long term freezer, roughly 7 days brick-hard frozen meat. Electrical, via battery, is a new adventure and I want to be sure I make the fewest poor decisions in the early stages. With that in mind...

First, judway and kdbgoat, a generator is out. I hate hearing generators when I'm camping (Provincial Park camping), even though I realize there are very quite gens, and I don't want to be "that guy". And I'm in Canada so American options are minimum 30% more $$ plus any possible duty bringing it across the border. Grrrr.

Gary, my logic for not running in parallel is because I want to have a "full" battery when the first one requires charging. My (limited) understanding is that running in parallel will offer greater capacity but will still leave me with probable charging requirements with nothing to cover that charging time (and I'd assume charging them both would take longer than charging one).

I did provide info about that tow vehicle (TV) - that was the f150 part of the post (not sure what else I should have provided?). As to the spare battery, I agree, I provided no info. In fact I know nothing about the main battery - I don't have it yet. However the spare is an "odyssey 34/78-pc1500" http://www.odysseybatteries.com/batteries/pc1500_series.htm and it's the spare because it's what I have (and I don't know what I'm doing ). My understanding is that I should not mix batteries with different ages/life, and the main will be new while this spare is certainly not new. For the spare I expect it to be fully charged before I leave and then swap it when I need to charge the "main". When requiring charging, the main would be charged in the bed of the f150, secured of course, while traipsing around the area. I'd assume driving with jumper cables running from the hood to the bed is not ideal. My thought was something connected to the 7-pin that terminated in bolt-on connectors to the battery (I'd assume alligator clamps would be too liable to bounce off). The spare would be expected to keep the fridge running while I'm gone.
I too expected that the fridge and water pump (the water would be used for late night "number one" from the 2 female campers; all other water requirements would be not related to the RV) would not use that much electricity (understanding of course that the fridge is "running" off propane and the battery is used in place of a pilot light). I just wanted to be certain that after 5 days of camping I wouldn't have a dead fridge. As to other power requirements in the RV, I fully intend to swap all the incandescent bulbs with LEDs, although I don't want to use the lights (fridge protection again, combined with inexperience). As to the inverter, I believe there is one on-board but small personal devices will be charged when (and if) the truck goes for a drive, or the kids are willing to sit outside the comfort station while charging their devices - we're camping dammit, put that crap away. lol. We've managed these many years by charging phones and "toys" while side-tripping or at worst, charging at the park office. I have no current plans to use any AC power in the RV.

And finally, kdbgoat, solar is something I'm investigating now. Like anything else we're new to, there's so much information available that it's difficult to sift through and come up with the simple, inexpensive solar solution. I understand that the solar I need is based primarily on my usage, but as I haven't gone out yet I have no idea what my usage will be. I've watched several solar videos that seem to indicate that given proper sun exposure, a relatively basic solar set up will provide enough of a trickle charge to the in-use battery to satisfy my requirements. But then what's a "basic setup"...

So my short term plan is to be extremely frugal with non-essential electrical use. Fridge only, RV lights only if they've been swapped to LED and then only for short periods. Using a second, experienced, Odyssey vehicle battery to provide interim power to the fridge while I'm re-charging the "main" battery on side trips (I still need to figure out how to make that happen).
My longer term plan is to include a solar charging option that will provide continual charging of the main battery, while maintaining strict electrical usage, and using the spare in extreme situations where the solar option gets rained out.

Sorry for the massive reply, and I hope I've addressed the shortcomings of my original post.
Brian

P.S. Sorry, I meant to add that I had investigated 2x 6v instead of 1x 12v. My purchase includes a "$100 battery", for them to make that 2x 6v they wanted another $600 (!!!). Clearly unrealistic (and how's that for a reality check for US rv'ers vs CDN rv'ers).

 

[Gary RV_Wizard]

Gary, my logic for not running in parallel is because I want to have a "full" battery when the first one requires charging. My (limited) understanding is that running in parallel will offer greater capacity but will still leave me with probable charging requirements with nothing to cover that charging time (and I'd assume charging them both would take longer than charging one)

You have the same battery capacity either way. The only difference is you get a warning if used singly and the first battery gives out before you are halfway through your stay. But feel to use whichever method is most comfortable for you. Yes, if you use them individually, you can [somehow] charge one while running off the other.

Two batteries may well last 9 days if used as you describe, but my guess is that you will quickly learn to enjoy the availability of power and start using more, e.g. for lighting. We are too easily sucked in by convenience of a wall switch!

 

[fubu]

Two batteries may well last 9 days if used as you describe, but my guess is that you will quickly learn to enjoy the availability of power and start using more, e.g. for lighting. We are too easily sucked in by convenience of a wall switch!

This is exactly what I'm worried about, lol.
I actually just got a mate to the Odyssey battery, so I'm thinking now I'll connect the 3 of them and include a 75w solar panel and tell the kids that the plugs inside the trailer don't work unless we're plugged. That might hold them off for a little bit...or not.
Thanks Gary!

 

[HappyWanderer]

You can buy a small 700 Watt gasoline generator at Harbor Freight for $87.79 this weekend if you have a store close by. This should give you a charging rate of about 50 Amps. I don't know how noisy it might be.

They also have a 45 Watt solar collector on sale this weekend for $119.99. Good for about 3 Amps charging rate. No noise.

That 45 watt solar is three heavy 15 watt panels tied together. For about the same price, you can get a single 100 watt panel on Amazon.

 

[KandT]

I would take solar and a chance to learn how it works over a generator or alternator any day of the week!

 

[fubu]

Coleman 75w solar panel, regular price $399, sale price $159. Bought it. Controller $20. Now looking for sunny weather, try this sucker out.

 

[Gary RV_Wizard]

A 75 watt panel in full sun can generate about 5 amps @ 15v Enough to replace a days usage in 4-6 hours of sun if the battery is low. However, once a battery reaches about 80% charge, it simply won't accept a very high amp rate and charging slows down no matter what panel you have or how bright the sun.

 

[fubu]

So if I understand you correctly, I'd be better off letting the batteries drain for a couple days before putting them on the solar panel? If it was overcast, I suppose then I might leave the panel on the batteries for longer (my understanding is that the panels will still capture energy even in overcast conditions, but at a significantly lower rate).

 

[Gary RV_Wizard]

So if I understand you correctly, I'd be better off letting the batteries drain for a couple days before putting them on the solar panel?

No, that is NOT what I was suggesting. I was merely warning you that once the battery reaches around 80%, it takes many additional hours of full sun to reach 100%. In practice, on an extended stay, your batteries will rarely reach a full charge and will cycle between the 50% and 85% level.

 

[kdbgoat]

Going back to the OP's original question- Yes you can set up something to charge your battery from the 7 pin plug while out running around.

 

[fubu]

No, that is NOT what I was suggesting. I was merely warning you that once the battery reaches around 80%, it takes many additional hours of full sun to reach 100%. In practice, on an extended stay, your batteries will rarely reach a full charge and will cycle between the 50% and 85% level.

I see, that makes sense. Thanks for that.

 

[robertusa123]

I see what you getting at.    All you need is a 12volt power plug with aligulator clamps that you can hook up to the battery and then plug into your vehical power port.  That way on outing requiring a drive your​ vehicle will charge your battery

 

[PaulinBaja]

I drive a pick up truck with a fifth wheel so this is simple for me.  But,

I have an additional battery in the bed of my truck.  it has a 7 pin connector that plugs into the in-bed fifth wheel connector when not towing.  I just plug it in there normally, even when at home and it keeps charged.  when traveling the trailer hooks in there and then the back up battery goes back into that plug when we disconnect.  Nightly or Daily I just plug the trailer into the bumper trailer connection point and run the two batteries together.  during the day the trailer battery gets little use and when connected together there is almost unlimited battery available.  Note we are careful with our usage.