Getting a charge out of batteries

A neophyte swabbie has a lot to learn. Learning on the job comes with challenges, and a price tag, but it also comes with the joy of accomplishment.
Monday through Friday I accomplish what the work-world demands. Come 4:30 pm Friday, I hop into my vehicle, enter a river of bumper-to-bumper traffic squeezed into six lanes, and head to the other river, the serene San Joaquin. 
Saturday and Sunday I swim, bird watch, read, fix things, and swabbie.
A good life, that requires energy.

Energy, packaged

Until recently, I understood batteries be be packs of potential energy purchased from AAA roadside assistants, or tech and grocery stores. My biggest decision was buying one-time use or rechargeables.
Then I bought a houseboat. Oh, how woefully under-prepared I was.
I listened and nodded as the couple selling their boat advised about batteries, generators, inverters, chargers. Certainly, I recognized the three car-size batteries sitting neatly on the transom, just as I recognized the "classic" 85 HP Johnson Sea Horse outboard motor next to them. Together, those objects, I knew, made the boat move. But I focused on the romantic side of houseboating and much of their advice was over my head.

You've come a long way, baby

Two of three batteries on the transom were dead. Before replacing them, I applied myself to learning about batteries, intending to purchase the best value for money with least negative environmental impact.
That intention led me down a path I'm still travelling.
Who knew that batteries offered such variety, and that boat/marine and car batteries were different?
Boats/marine/RV batteries are deep cycle geared both to start engines and provide energy for on-board systems when on the water (away from marina slip).
Car batteries, aka "starting" or “cranking", provide enough power to start cars' engines.
Who knew that there are the four chemical types of batteries?
Well, Sailor for the Sea knew, and they offer this illustration of wet cell (flooded), gel cell, absorbed glass mat (AGM), all lead-acid, and lithium.  (Visit their website, too. It focuses on protecting the health of bodies of water.)

Good overview of batteries from Sailors for the Sea. 

I've come a long way and, yes, I still have a long way to go. But I've taken my first steps.
I learned enough to purchase a new deep cycle battery and recycle the two that no longer work. While I haven't yet purchased a battery charger - I'm still reviewing my options - I regularly start the 85 HP 2-stroke outboard to keep it tuned. For, one of these days - after I pass the boating safety course - I intend to take my houseboat out on the river. Mine is, after all, a riverine romance.