Recharging batteries while boondocking?

BobCaesar · 03-17-2007, 08:40 PM

Just joined - hope I am doing this in the correct place, manner and form ! I do appreciate your input to this newbie!

What is the best way to recharge RV batteries after a few days of boondocking, while still out there? My guess running the tow vehicle engine is first (maybe the only), but how long would you have to do it and would the "charge" come through the trailer's converter?

The only other thing I can think of would be an expensive generator. generator. Would you power a reg battery charger or again power up the entire trailer system and rely on the converter?

Your advice will be most apprecioated!

Thanks - Bob

BobCaesar · 03-17-2007, 08:40 PM

Just joined - hope I am doing this in the correct place, manner and form ! I do appreciate your input to this newbie!

What is the best way to recharge RV batteries after a few days of boondocking, while still out there? My guess running the tow vehicle engine is first (maybe the only), but how long would you have to do it and would the "charge" come through the trailer's converter?

The only other thing I can think of would be an expensive generator. generator. Would you power a reg battery charger or again power up the entire trailer system and rely on the converter?

Your advice will be most apprecioated!

Thanks - Bob

Doggie · 03-18-2007, 05:51 AM

Solar panels, a wind generator or a small gas generator and a good battery charger.

**Gary RVRoamer** · 03-18-2007, 06:00 AM

Running the tow vehicle's engine will work IF the tow wiring connection was wired for it. 7 pin plugs have a position for a charge line that will do that if so wired on both the tow vehicle and trailer sides, but I have seen tow vehicle installations where the installer did not bother to do so. Trailers usually come factory wired that way, but sometimes the connection gets lost over the years, e.g. corrosion at the battery end.

When using the tow vehicle, charging does NOT come through the trailers converter/charger - the converter is powered only by 120VAC from the shore power cord.

It takes ages to recharge dead batteries with the tow vehicle, especially at idle speed. The tow vehicle's alternator does not put out a lot of current at idle, so figure on hours and hours of charging. At higher RPMs, maybe 1200 or so, charging will be faster but it still takes hours if the batteries are down to 50%. It is better to charge some every day (or even twice a day) than waiting until the batteries are almost dead.

A battery can be recharged to 75-80% of capacity in an hour or two, but it takes many hours to get back to 100%. That's because the rate of charge slows dramatically as the battery gets above 80% charge.

Cubey · 03-18-2007, 07:58 AM

In my opinion, the best bang for the buck is a small generator vs solar. Sure, it's noisy and costs you gas/oil but it also provides a lot of instant, reliable power 24 hours a day.

On my TT I had to completely do a new inner 12v system, there was nothing left at all other than two ceiling 12v fixtures but even the wires to them where they originally led to are lost inside the wall. The last owner chopped them off too short and when I attempted to save them they went into the wall. So oh well. All the 12v system inside was done by me so if I have a problem I know what's what. Anyhoo, I went ahead and wired up one of the connectors for the 6 way wire harness es I bought and installed on the TT and van so the keyed "aux" 12v from the van will go directly to the battery on the TT so it'll get some charge while towing.

While I don't have an absolute need for 12v power if boondocking as I can rely on propane for cooking and light (there is a propane wall light). Only thing I'd probably NEED is 12v for the LP detector (very small draw) and fans for cooling/airflow. However I'm still considering a smallish, cheap generator for occasional/emergency use, such as a 1000W. It would be compact enough to store away easily when not in use but more than enough to power the RV converter and a few other low power draw 120v devices if needed. I have a lot of 12v devices however so powering the converter would power everything 12v as well at the same time as charging the battery so I would almost not need 120v aside from for the converter.

Lorna · 03-18-2007, 10:18 AM

If you get a generator, you need to watch the noise level. Most parks have a noise limit. If you check out the rules posted on State, Federal, National Or COE website, they should list the noise level. I think the Honda EU's will comply. The "contractor" type units you need to stay away from (way too noisy). Many parks also limit the times you can run a gereator. Again the websittes will tell you. I know nothing about the BLM land rules and you do not say what areas you will be camping in. That makes a big difference.

BobCaesar · 03-18-2007, 10:52 AM

I should have mentioed we live in rural NW Wyoming (Yellowstone Country)and camp only in remote locations here and in Southern Utah. We often take our horses along so are not often near anyone. Would only run 12v lights, water pump, but sparlingly.

Now I am thinking of the pros & cons of charging TT batteries using jumper cables direct from the tow vehicle battery to the TT batteries. Is that too much, too fast? A generator would be nice, but $?

Thanks for all the great help!!!

Bob

BobCaesar · 03-18-2007, 11:46 AM

A little knowledge is a dangerous thing, but the thought occurs - it may be better to use an inverter from the tow vehicle to run a standard battery charger connected to the TT batteries.

Am I trying to reinvent the wheel?

Cubey · 03-18-2007, 03:47 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Lorna:
If you get a generator, you need to watch the noise level. Most parks have a noise limit. If you check out the rules posted on State, Federal, National Or COE website, they should list the noise level. I think the Honda EU's will comply. The "contractor" type units you need to stay away from (way too noisy). Many parks also limit the times you can run a gereator. Again the websittes will tell you. I know nothing about the BLM land rules and you do not say what areas you will be camping in. That makes a big difference. </div></BLOCKQUOTE>

It would be for boondocking, not park use. If I'm at a park I can plugin to 120v.

Mutha · 03-18-2007, 04:13 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BobCaesar:

A little knowledge is a dangerous thing, but the thought occurs - it may be better to use an inverter from the tow vehicle to run a standard battery charger connected to the TT batteries.

Am I trying to reinvent the wheel? </div></BLOCKQUOTE>

Bob, here is required reading for you!

If you read this and still have questions then this is the place to ask them.

All about Batteries & RV electric systems

Good luck, Glenn.

Lorna · 03-18-2007, 05:15 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Cubey:
...It would be for boondocking, not park use. If I'm at a park I can plugin to 120v. </div></BLOCKQUOTE>
Trust me, you WILL want a quiet generator.