Best way to supplement battery bank?

With 230 watts of solar I would say you will be fine with what you have. During hunting season I do what you do and take along 2 more batteries just to have the extra AMP hours in case of cloudy weather. I took a set of jumper cables and cut them the length I needed to reach from the battery on the trailer to the first battery on the ground then I cut two more shorter leads to connect the second battery on the ground. I crimped on 4 gauge battery lugs to the jumper cables so its easy to hook them up and get a good connection.

Hook up all 4 batteries so the solar can keep then all charged and you don't have half charged batteries setting around for a week.

In a pinch you can use the TV alternator to push a little current into the trailer batteries with jumper cables. I would do this in the AM, when the voltage differential between a running alternator output and the trailer batteries is highest. Let the solar do the bulk of the work over the day.
Another (better) long term option is more solar, then you don't have to worry about this again, even on longer trips.

You did not state what type of RV you have, but if it has a modern CO meter, propane detector and refrigerator, then they will consume about 30 - 35 AH daily. This is about what one of my 120 watt solar panels will put out in a normal day. You have very long days in Canada right now, so I am sure that you can collect some 100 AH daily in your long summer days.

This will be more than enough power to fully charge your batteries daily, unless you are using the furnace, or leaving a laptop run all day on inverter power.

You probably also do not need to run the lights much. The water pump draws 7 amps per hour, and can pump 2 gallons per minute, thus 120 GPH for only 7AH of power - 84 watts.

You will be fine without the extra batteries.

I would leave the truck running while deploying the slides, as they will take a lot of power for a short time. And then check the battery meter before leaving. If it reads nearly full, you do not need to idle the engine - the battery and solar provided plenty of power to run the slides.

While the slide motor uses a large amp number, a 60 amp motor run for only 1 minute is a total of 1 amp hour. Your battery will store 220 amp hours. . .

Have fun camping!

Fred.

Jetta03 wrote:
Just trying to be prepared (murphy's law), and had the question :)

Yep, life's big mysteries... Murphy's law & Timothy Treadwell.

If you must bring them 12 volters you may as well connect them every day. Some jumper cables or #6 wire is fine.

If they have been sitting a bit it might be a good time for an equalization charge.

Just trying to be prepared (murphy's law), and had the question :)

Jetta03 wrote:
Thx all. Like I said we've gone this long with solar only with no issues in the past.

If you've dry camped for 10 days in the past & it worked then with two 12 volt batteries.... why are you asking now ? :h

Thx all. Like I said we've gone this long with solar only with no issues in the past. We're not using alot of power, and the solar more than covers refrigerator and water pump, radio, etc. even in sketchy condition. Generator is not an option, absolutely hate them for camping, won't own one, and we have no pressing need for microwave, AC, or hairdryer :R. Wife and girls will survive just fine without them for a few days.

Question was more about how to best use spare 12volts in a pinch. Sounds like best option is to simply swap out if the time comes.

Assuming you will be in a remote area & not surrounded by other campers & you have time to order a generator.

And, you can't borrow one.

It will also run a small microwave or hair dryer.

I highly recommend this one.

Champion 1500/1200 ...... $200

Jetta,

I personally believe that schlepping the other 12Vs along will be an exercise in futility. Unless those 12Vs are 4 or 8Ds (BIG HONKIN) batteries, they will have no where near the capacity of the T-105s. You are also talking about 10 days. With no way to recharge things but the tow vehicle or solar, if you end up power down it will be bad. If you plan on trying to recharge from the tow vehicle, remember that nothing good happens to an idling engine.

If you were to acquire a very small suitcase generator (the newer of these can be very quite) and a good smart battery charger, you could recover a depleted bank to a usable lever in a few hours. A charger that is charging a 12V bank at 40 Amperes is only drawing about 600 Watts, so any generator larger than that should be adequate.

I did a lot of boat work before the depression and this was the successful trick suggested and used by several Mackinac racers (sailboats) that could not use the engine to charge their batteries that were required for instruments and navigation.

Matt