Please be aware that Charlie is so full of bovine dung on a lot of this article that it is barely laughable to anyone who knows what they are talking about. One needs to consider the point that Charlie is perhaps the last external regulator maker on the planet claiming "faster charging", as their primary marketing push. He can only do this at voltages of 14.8V and above, often above 15.0V+, otherwise his claims are pure BS because 14.4V is 14.4V is 14.4V all day long to the battery. You can't do 14.8V+ with GEL and AGM batteries so he bashes them as being useless because it gets in the way of his fast charge (at super high voltages) claims.....Sorry to drag this battery discussion out. I was getting confused with these "Dual Purpose" Marine/Starting batteries.
A friend told me that there only two types, starting and deep cycle. That dual purpose, or DeepCycle/Starting batteries are marketing propaganda.
Wanting to understand, I did a lot of online research and made some phone calls to manufacturers. So, as Maine Sail said, the only battery to care about is the true Deep-Cycle. Anything else is not rated to cycle.
I found this on Sterline-Power's site and it is pretty much verbatim what my electrician friend told me... Take it FWIW...
The brutal truth about marine leisure batteries
http://sterling-power.eu/support-faq-2.htm
There is no such thing as a marine battery.
SNIP """"""""""""""""
Conclusion
The best battery to use for fast charging using advanced charging systems
For general leisure use: use low cost Lead Acid which can be topped up with water. So called leisure batteries
For long term cruising then use 6 volt traction
Avoid Gel / AGM for 3 reasons
very expensive
their fast charger rate causes them to gas
poor cycling numbers.
His claims on GEL cycle numbers are also entirely bogus and this can be easily verified by actual nationally funded fully independent laboratories such as Sandia National Labs.....
Beyond that next time you are at Annapolis or Newport or any other boat show where Ocean Planet Energy / Bruce Schwab Energy Systems is, stop into the booth and ask Bruce what bank of batteries he circumnavigated the globe with TWICE.... Yes the same bank of GEL batteries survived two solo around the world Vendee Globe challenges, same batteries around the world TWO TIMES. The life of batteries aboard a round-the-world race boat is NOT an easy life and Bruce quite regularly took them to 80-90% DOD.. But yeah GEL's suck.... Utter rubbish.
While much of that article is spot on, that article was most likely written to back up other unrealistic claims made by Charlie.... I have no qualms calling Charlie out on this because I have done it person to person and I am a Sterling dealer. I sell a lot of Charlie's stuff and have zero issues calling him out when he creatively markets... I don't purposely molest/twist the truth/reality to my customers but Charlie sometimes does.
He's all about marketing, no matter how creatively he does it...... Brilliant guy, makes some excellent products but is a marketing maven above all else.
Please read carefully and you'll see that his fast charging claims are not directly geared towards "traction batteries" but rather towards cheap thin plate refillable flooded batteries akin to our US starting or dual purpose batteries.. Why? Because he knows damn well what happens when you try to charge thick plate deep cycle flooded "traction" batteries quickly as do all the actual battery manufacturers..
What should the key take-away be?
2V or 6V or 12V (12V - apparently he is unaware these exist) "traction" (eg: golf cart / fork truck / sweeper scrubber) batteries are a great deep cycle battery