2nd Battery Install

You'll want to make sure your original battery is still fairly new if you'll parallel a 2nd battery with it.  You should start with two batteries that were made at the same time, same brand, etc.  The best thing you can do is to get two 6 volt batteries and wire them in series, which gets around a few issues you can run into with paralleled batteries.  

Originally posted by gpod Also, once connected, will a trickle charger charge both when only connected to one?  What about charging it from the car or regular power line... any implications with this? Thanks!

They're spot on with the batteries. Two identical deep-cycle batteries will make dry camping much, much easier for you. The very best are Trojan T105 golf cart batteries, which are 6 volt. They're a bit pricey at around $140 each, but their longevity is the best out there.

On the charging, however, I want to warn you about trickle chargers. Never ever use a straight up 'trickle charger' on any battery. Here's why. A trickle charger dumps a small, constant current into your batteries no matter what. This creates multiple problems. First, a trickle charger will take a very, very long time to recharge a mostly discharged battery, and it will never be able to bring a completely discharged battery back up (due to its inability to 'burn off' the sulfation buildup on the lead plates inside).

Second, if the trickle charger is indeed giving your batteries enough amperage to keep them fully charged (which it might not), it's probably giving them too much. Too much charge results in boiling off needed water from your batteries, and unless you check and replace the water levels very regularly, this will shorten the life of your batteries. Too little charge will ultimately result in complete sulfation of the batteries (meaning that they will be dead forever).

Now the problems with slightly over/under charging your batteries might not be noticeable for some time. Generally, the batteries will just slowly give out, albeit much faster than they should. Eighty percent of deep cycle batteries are dead forever within three years of purchase. Properly maintained, they can go for 8-10 years.

That's why you need a smart charger that will sense what state the batteries are in and adjust the amperage flowing into them up or down appropriately. Schumacher smart chargers available at Walmart and the web do a good job of this. Put your batteries on such a charger and leave them connected to it (multiples are fine if connected in parallel) 24/7. A better option for maintaining your charged batteries, though, is a battery maintainer. I've used the BatteryMINDer #1500 very successfully for maintaining my batteries. One of its best features is that it adjusts the voltage depending on the ambient temperature, which makes a definite difference. No 'dumb' trickle charger will do that. It's a slight investment at about $49, but if it doubles (or triples) the lifespan of even one battery, it's well worth it.

If you're at home, you should leave the batteries connected to a smart charger all the time. If you're out camping, just connect the Pod to shore power and the built-in smart charger will take over. You can also charge your batteries with a smart charger (not a maintainer in this instance) connected to an inverter connected to your running vehicle (sounds more complicated than it really is) to get them up to around 80-85% charge (sufficient while on a trip) in a few hours at most. Or you can use solar panels (others and myself have posted about this in this forum), but they're slower and dependent on sunshine.

Sorry for the long post! I just want you to have the best info out there. Take care.

Originally posted by gpod When I connect the "smart charger"...... or would I connect the + terminal to one and the (-) terminal to the other?

That is correct assuming you have two 12V batteries in parallel.

Originally posted by techntrek Also true for two 6 volt batteries in series.

Doug,

How funny. I had written the same thing in my original post, but then realized there is a way to hook plus to one batt and neg to the other and really be in trouble, so I deleted it. I'm basically a cautious chicken

will, does the battery minder work for ytwo 6 volt batteries in series.  we are about to change over.