This says theses batteries can be both charging and deep cycle for both applications. They are expensive but if they work they will be well worth it.

http://westcoastbatteriesinc.com/nor...ies/nsb27f.htm

It says they will last longer BUT how much is longer??? Many others make the same claims just as Optima does. I replaced all mine with blue tops one year and they did not last any longer than a $100 battery from Walmart. However they will charge faster and hold it longer but at near triple the price, they aren't worth it!!

The web page says they are good for 400 cycles and they say they will last three times longer. I am just reading what they say. I found them on another site and was amazed with their claim they could use starting batteries for their deep cycle batteries and vice versus.

I had the same experience as Bulletman 99

Just as I said Optima makes the same claim but my experience with them was not good. I spent nearly $900 on those 3 Optima Blue-Top batteries and would have been better off spending $300+- on standard marine batteries. Now the new lithium batteries are different animals altogether. I have a friend that swears by them. Quick charging (requires a special charger) much lighter in weight but WOW check out the prices for those things. I can replace several sets of standard marine batteries at the cost of 1 of the lithiums!

I know some guys that are running lithiumPros and one is on 8yrs and the other is 6yrs, the only time it is worth the cost of running them is running 3 or more graphs and to cut weight.