In Reply to: 12 volt electrical Question? posted by steveVa on December 07, 2017 at 14:03:27:
To answer some of your questions: Yes there are 12 volt LED light bulbs that screw into regular sockets, I have seen them at Camping World, so any RV shop should be able to get them.
If one battery has a bad cell when hooked up in parallel OR series the charger will continue trying to bring it up to set voltage, that will cook the good battery and ruin it. If one battery in a set goes bad, replace both; never use an old battery with a new one.
Surprised that the battery isolator didn't work, don't know about that.
You mention "high amp battery's", if that is cold cranking amps then you have the wrong battery for your application. That is a starting battery designed to produce high amps for a short period of time, batteries marked RV/MARINE/DEEP CYCLE are actually a combination style with thicker plates, but not true deep cycle. A true deep cycle battery has thick plates to produce energy over a long period of time, such as "6 volt golf cart batteries". Just bought two of these today for our motor home; $87 a piece at Costco. These batteries have a 210 amp rating at a standard 20 hour load.
One of our neighbors up in the hills has an array of solar panels with ten of these 6 volt golf cart batteries hooked in a series/parallel configuration feeding his large inverter.
Well this is probably more than you wanted to know, but I hope some of it helps you.