tplife wrote:
+2 for AGMS as the way to go. They last longer, take A LOT more abuse, can be mounted inside living areas, upside down or sideways, can be discharged lower without damage, etc. The advantages are too numerous to list. :B
Battery Info
I have been 100% AGM since Jan 2009. See my profile for my current configuration. In Jan 2010, I switched the van to AGM for starting service.
For me, I wanted to install inside living spaces and not worry about H gas and acid mist as a regular event during use. AGMs fit that situation.
Do they last longer? I don't know.
Abuse wise, I believe AGMs are better on discharge abuse but worse on charging abuse. Charging abuse is when you use higher volts than recommended. AGMs can be charged by your alternator or any regular automotive charger(not the deep cycle setting). A temperature compensating charger is recommended.
Wets are opposite, with the bigger difference being weaker on discharge due to rapid volt drops especially during higher draws. Higher draws means inverter use, not the 5A draw as with your furnace fan. Volt drops means that your inverter shuts down sooner. Inverters are becomming more common in RVs.
I have never seen an AGM mfgr recommend upside down orientation for installation, however, there is no problem during use as with flying. Side or end is fine. The orientation advantage will mean more choices when fitting a battery into an available space.
On cost, we all know wets are cheaper to buy. After 5yrs the monthly purchase cost is ~$1 for wets and ~2$ for AGMs, based on 100AH. You will soon forget the cost. If you can maintain a wet for less than $1/mo, then they are right for you. Keep in mind that I don't need:
1. a special charger with a deep-cycle, equalizing, and conditioning selection;
2. a hydrometer, a gallon of distilled water, safety glasses, wool pants,
3. a sealed box with holes drilled into my van and TT to let the gasses escape.
4. None of the time associated with the above.
I have discharged my Deka many times down to 11.8V as measured in the AM. That battery tested at 12.8V recently after a 24hr rest.
HTH;
John