Batteries

Considering that a LiFePO4 battery can last 10+ years, and can be drained below 50% without damaging it plus other advantages such as weight savings, the cost isn't as steep as you think. Yes, the battery costs more than the typical Pb-acid battery, but over the lifetime, you will likely need to replace the Pb-acid battery/batteries multiple times while you would still be using the LiFePO4 battery. LiFePO4 batteries also charge quicker. They don't need a float charge and the have a very slow self-discharge rate. 

The expenses other than the battery are the converter upgrade (if needed), and a DC to DC charger since your tow vehicle likely won't charge the battery as you are driving. This is because the newer "smart" alternator control circuits think the TV battery is charged and reduce the output to save gas. The trailer battery supplies what the TV needs so you arrive with the trailer battery partly discharged. I set up a separate charge circuit with a battery isolation solenoid for the TV that can feed a circuit connected to the DC to DC charger which then charges the LiFePO4 battery. The Grey Wolf came with solar, but it has a cheap PWM charge controller. I purchased a Renogy MPPT controller which will let me connect the TV power in addition to the solar panels. That means that I won't need the Renogy 20A DC to DC charger that I had been using in the RPod either. The last thing you would want would be useful even if you stayed with Pb-acid batteries. That is a way to monitor state of charge. The one I have mounts a shunt through which the negative terminal is connected. It drives a meter that shows voltage, amps in/out, and percentage of charge. It is much better than the "idiot" light gauge that was in the RPod. There is some wiring that will be needed, both for the TV and the trailer if you were to duplicate what I did. However, you may be able to skip the TV part and use the power from the 7-way if your TV cuts that power when the engine is off. You could disconnect the wire from the 7-way on the trailer end and connect up a wire to a DC to DC charger instead. You can't just connect the DC to DC charger into the trailer's existing wiring for supply because then it would be like trying to use the battery power to charge the battery. It just doesn't work.

I detailed the installation in my mods. I removed that equipment and the only things I will be using for the Grey Wolf are the 200 AH LiFePO4 battery and the monitor.

Anyway, I hope that is helpful.

Originally posted by Pod People So, good for you.  I think you have made a wise move going to the GC2's. the fact they they are not maintenance free is NOT a big deal. Just check the water levels and fill with distilled water occasionally.  I try to check once a month, but honestly in almost 2.5 years, I have added a small amount of water only once.  I have cleaned the terminals with baking soda and a stiff brush and check connections for tightness. Travel safe and often Vann

Yes, Yes, maintenance is key for battery longevity!  I do this as well, keep terminals clean with baking soda and check water levels; pretty easy.  Even during the winter here in northern Michigan both batteries had water levels checked and were given a 24 hour 2 amp trickle charge on Nov. 1 and 2 last year.  After that they were placed directly on a concrete floor in an unheated garage where they remain now.  Once/month their voltage level is checked with a multi meter.  As of yesterday the Interstate reads 12.61v and the Trojan is at 12.68v.  As we boondock often, voltage is checked daily, when battery reads 12.2v it is swapped for the other 'fully charged' battery.