AGM Battery Question

The LifeLine technology was developed for aircraft. There is a lot more current draw while starting a turbine engine than there is for starting a diesel.

I have one for the chassis and two for the house that were installed in January of 2004.

So, I guess you could say that they are dual purpose but I wouldn't say that for any other brand.

I put a AGM in my Saturn a year ago. Sam's Club offered regular flooded cell and AGM. I went the extra $50. for the AGM and corrosion free. I enjoy the clean maintenance free part.

Not all marine deep cycles are dual purpose. They are engineered for totaly different purposes.
One is a "true" deep cycle engineered for trolling motor use and is used by most tournament or avid fishermen.
The marine deep cycle/starting battery is used not only as a starting battery, but power the electronics, ie. fish locators, lights, depth sounders, live well pumps etc.
The internal construction of a marine battery is quite different than a standard deep cycle and is not needed in an RV, plus they are more expensive.

flyfishing48 wrote:
Flooded batteries come deep cycle and cranking. The AGM batteries that Camping World has on sale are shown as "Dual Purpose". Aren't AGM batteries designed as deep cycle and cranking or they in fact dual purpose?
Not looking to buy a battery right now, just want to know.

What battery? Have a link?

AGM tends to have superior CCA even for a deep cycle so they are marketed as both even if primarily designed for deep cycle.

For this post there are three classes of battery

Flooded
Maintenance free exclusive of AGM
AGM (Sub set of Maintenance free)

The first and last can be easily found in DEEP CYCLE, Marine/Deep cycle, or starting batteries

The middle one is a bit hard to find in DEEP CYCLE, but in theory should be possible.. Just never saw one (Perhaps a trolling battery)

The Dual Purpose are Marine/Deep ..

Regular starting batteries are rated in both cranking amps and cold cranking amps, This is because they need to deliver a lot of energy very fast. But in terms of their total capacity, not all that much.. They like to be kept well fed.

Marine batteries they drop teh COLD cranking amps (Cold is less than freezing point of water) but are otherwise the same. Which is why I do not distinguish between those two

Marine/Deep cycle are mostly starting batteries, they behave like starting (Marine) batteries however they can be run down a little bit more than a true starting battery. I'm going to run a few numbers in a bit.

DEEP CYCLE, are designed for a slower (Relative to capacity) discharge but can go to 50 percent state of charge before serious damage happens.

Starting,, Normal amps less than 100, Normal time less than 30 seconds, perhaps times 5 just to be sure.

250 amp minutes = roughly 30 amp hours. Most starting batteries are at least 75 amp hours (or larger) and darn few engines need 2.5 minutes of cranking to start.

The 8.1L Vortec on my motor home would start with a 73 amp hour battery that had more than 50 percent cranking amps.... Think about this. Not a lot of juice

I have started as many as 5 cars off a 27 hour (1,000 amp peak) jump box without recharging, this gives you an idea of the amount of total energy a cranking battery is designed to deliver. That box had an AGM inside it.

Keep cranking batteries at least 75% charged for better life.

You do not want to use any dual purpose battery as a coach power supply. It is not designed for that purpose.
Yes they are dual purpose used mostly in boat applications.
There are deep cycle AGMs for thar purpose.

Check the Optima website and get some answers from the experts.

Optima batteries

I put a new flooded style engine battery in my Bass boat a couple months ago and it also was called "Dual Purpose"