safe to use sealed batteries in coach?

rich85704 wrote:
In response to some: what's the difference between a sealed flooded battery and an AGM battery? Are sealed batteries not really sealed?

R

Books are written on the differences between the Flooded Wet cell and AGM batteries. When you read forums, there is lots of misinformation on both. I will offer a short version which may generate more questions.

Flooded Wet cell batteries are the most common found in cars, and much cheaper to build than AGM batteries. Flooded Wet cell batteries are made up of plates which are suspended in acid (liquid). The liquid must cover the plates. When the battery is charged, its normal charging results in some of the liquid turning to gas. Typically this gas is contained inside the battery and turned back to a liquid. The reason we have to add water periodically is because the gas has escaped from the battery. This gas can make you sick or kill you. In my opinion, a sealed Flooded Wet cell battery in theory at least allows less gas to escape.

AGM (Absorbent Glass Mat) is often confused with Gel batteries. This is from the following link Battery University:
The sulfuric acid is absorbed by a very fine fiberglass mat, making the battery spill-proof. This enables shipment without hazardous material restrictions. The plates can be made flat to resemble a standard flooded lead acid pack in a rectangular case; they can also be wound into a cylindrical cell.


I personally have had flooded wet cell batteries in RVs since the mid70s and everyone fail due to my lack of maintenance. The AGM requires no maintenance. AGMs tolerate cold much better than Flooded Wet cell with the added benefit I can use it inside the RV where I have better temp control. My friends and I have used Lifeline and Universal brand AGMs with no complaints. We no longer have to mess with adding water to our batteries and can leave them in storage disconnected for several months and they will be fully charged.

Wayne