running appliances and battery charging

I have the RPOD 177. I only need electricity for the water pump and a few LED lights--no TV, NO AC and the frig will be on propane. I will only be in non electric campsites for 3 day periods. The golf cart batteries from Amazon, ANSTON 6v are $195 each at Amazon. That is almost $400 plus the box for another $100. I could go solar for less than that and for a few bucks more go for Zamp. I am thinking I will start off by sticking with my 12 v. that came with the unit and see how long that lasts by judiciously shutting the pump off when not needed and using a few battery lanterns at times.

George,

A few extra points: six volt GC2  batteries are available from Sam's Club for $85 each. The amazon price is way too high.

Battery boxes are purely cosmetic. The batteries don't need protection from the elements.

Good Trojan GP24 batteries are 85AH. Most less expensive GP24s supplied with trailers are 70 or less. A good pair of GC2s are 230AH. Do the math.

Even with solar you will want plenty of battery capacity in case of rain or shade.

The water pump does not draw any current unless it's pumping. No need to turn it off, unless you have a leak.

Originally posted by WillThrill Originally posted by WillThrill Originally posted by CharlieM If you're talking about direct connection with a set of heavy duty #4 copper jumper cables the answer is it depends on you TV.http://www.sears.com/diehard-platinum-20ft-450a-4-gauge-booster-cable/p-02871304000P?prdNo=3&blockNo=3&blockType=G3TVs' electrical electrical systems vary as to charging voltage and this varies the charging rate. Pretty much a trial and error situation. Try and hour at idle and measure the open circuit at rest voltage of the battery. Adjust up or down depending on results. If you're talking about charging through the 7 pin Bargman connector, the answer is probably never. I've used the jumper cable trick before to get out of a jam with a rented RV. Apparently, the battery on the RV was already badly sulfated and would not hold much of a charge: running the refrigerator's electronic circuit board only (the unit was being cooled with propane) completely discharged the battery in less than 24 hours. At any rate, you must be careful of sparks with the jumper cables, and you must be sure to start the TV immediately after connecting the cables to the Pod's battery. Otherwise, you may drain your TV's battery and be unable to start it. FYI, most vehicles' alternators output 20-50 amps while idling. Considering that most TVs are bigger than average, you're probably looking at at least 30 amps of output. It would take about 3 hours to completely recharge a dead marine battery at that rate. Keep in mind also that this is not 3 stage smart charging, which is best for battery life: it's a raw current dump. But in a pinch, it will work. You should ALWAYS have a set of jumper cables with you anyway. :)

Is there a 12v -> 12v charger that would work better than straight jumper cables?

Is there any reason you couldn't dual purpose a slightly over sized pwm solar charge controller that could be fed from panels or jumper cables?  That way the batteries received a quality charge either way.  Sunny days get panels, shady days get the cables.