2 Batteries ???????

[jdonham]

I have a 2007 starcraft 2409 pup and I only have 1 battery. How can I hook up another battery in tandem with the one I have? Also, will my stock converter on the pup handle the load of charging both batteries at once. I know adding another battery will increase my tongue weight but I am not overly concerned about it as I weighed it and I am still under the tongue weight limit of the truck even with the weight of a 2nd battery. The only things in the pup that run off of battery is the water pump under normal use, lights for maybe 60 minutes a night, and the furnace which we have only used to warm up the pup in the evenings before bed and in the mornings before we get up. I just need a less expensive solution to extending our boondocking time until September when I will be able to afford a Honda or Yammi geni.
Thank you in advance for any and all help.

Jason

[dthurk]

Buy a second battery the same group size as the one you have now.  Buy 2 short battery cables with ring connectors and connect the positive battery terminals together and the negative battery terminals together.

[wavery]

You might want to consider just carrying a spare battery, in a proper battery box, in your TV with a pair of inexpensive jumper cables.

When your camper battery gets low, just disconnect the positive (black) cable from the battery and hook the red jumper cable to it. clip the black jumper cable to the frame somewhere. Just keep in mind that on the camper, black is positive and white is negative. On the jumper cables black is negative and red is positive. Be careful not to mix them up.

[AustinBoston]

Buy a second battery the same group size as the one you have now.  Buy 2 short battery cables with ring connectors and connect the positive battery terminals together and the negative battery terminals together.

I generally recommend against connecting two batteries in parallel unless they are of the same brand, type, size, age, condition, and state of charge.  In other words, if they came off the same line on the same day, they are OK to parallel, otherwise, don't.

Having said that, this is exactly what we do when we hook up our trailers.  We hook two very different types of batteries - one a starting battery capable of huge bursts of current but not designed for sustained loads, the other a deep cycle battery that will sustain a load for a long time but would really strain to start a vehicle, probably of different ages and from different manufacturers - and hook them together in parallel through the charge line.

But personally, If I were dry camping, I would hook up one battery, and when it discharged to about 50% charge, swap it out for the other.

OTOH, if you use two 6-volt golf cart batteries in series, then they MUST be identical, or they will try to destroy each other, and one will win.

Austin

[jdonham]

Thanks for the help so far. The 2 6 volts sounds like a good idea but I am unsure how to do it. Does anybody have any pictures and step by step directions.

[dthurk]

2 6 volt batteries is what we do.  Buy two 6 volt batteries, we got ours from Sam's Club for about $65 each, IIRC.  Hook them up in series, not parallel.  Connect one of the positive terminals on one battery to one of the negative terminals on the other.  You will have two open terminals remaining, a positive terminal on one battery and a negative terminal on the other.  Hook those open terminals to the positive and negative leads from your camper.  

The advantage of 6 volt batteries is that you have a true deep cycle battery, not a hybrid version.  The lead plates are much thicker resulting in much greater battery longevity (not charge life) as compared to the marine deep cycle batteries.  Never discharge your battery greater than 50% (12.00 volts with a digital mulitmeter) and never let your plates become exposed to air from repeated charging.  Use only distilled water to refill them.

If you really want to spend the bucks, probably the best battery to buy would be an AGM battery.  They will never need refilling, and can be used in any position, even upside down.  It's up to you to figure out why you would want to use a battery upside down, but the AGM's can do it.

[harleywolf]

If you click the PUT Magazine link at the top left of this page there is an article there walking you through hooking up 2, 6 volt golf cart batts. as a 2nd battery for your system. Also here is the link.

http://www.popuptimes.com/articles/current/2batteries.shtml

[Peter_MA]

I don't see the value of using 2 6volt batteries. We always dry camp and often for a week or two at a time. I have 2 12 volt batteries that give us the same capacity as 2 6volts. When one is depleted I swap in the other and can usually find a 120v place to charge the low one, either with my little charger or a nearby garage. The PUP systems stay in business and I have a few days to get around to the recharge.

[AustinBoston]

I don't see the value of using 2 6volt batteries. We always dry camp and often for a week or two at a time. I have 2 12 volt batteries that give us the same capacity as 2 6volts. When one is depleted I swap in the other and can usually find a 120v place to charge the low one, either with my little charger or a nearby garage. The PUP systems stay in business and I have a few days to get around to the recharge.

The primary difference is in the number of discharge/recharge cycles the batteries can withstand.  Even supposed "true deep cycle" 12V batteries end up with some starting-like compronises slipped in.  6 volt golf cart batteries don't.  The result is they can stand up to more frequent and deeper discharge/recharge cycles than nearly any 12V battery, even so-called "true deep cycle" batteries.  Whether or not the extra cost is justified depends on how often you dry camp.

Austin (two 12V batteries here)

[brisco]

You guys/girls would laugh at my set up.. Since I dry camp a lot, but only need the battery for the 2 stock overhead lights in my old coleman, I use one of those small lawn mower batteries. My trips are usually only about 2-3 nights and haven't had it go dead on me yet. I probably use the lights 1-2 hours each evening, so that's not much use. One advantage to this is the battery weighs maybe 5 lbs or so and is easy to move (I take it in during the winter and for charge). I guess I could also charge it up while mowing my yard! (I don't want the wife to find out about that one! . Later, brisco