Originally Posted by farafield
I am thinking of getting a second Lifeline 24t battery. I have the factory installed 80w solar panel. If I hook up both batteries in series will they both get recharged by solar/shore power/tow vehicle? How do I attach solar cables to accomplish that? What I'd like to avoid is having to unhook one battery and hook up the second one when the first one is drawn down, i.e. both batteries hooked up all the time and getting recharged by either solar or shore power or tow vehicle.
You don't want them in series, but in parallel. I've got 300 watts and a simple pwm charger, charging 4 Lifelines. Works great and gives all the power I need. In fact I never have my batteries charged by anything else but solar.
What you want is battery cables of equal length to both batteries from the charge controller. Use at least a 6 gauge wire, but 4 is better. How old is your original battery? You want the batteries to be similar in age and identical in specifications. If they are mismatched then you will loose performance. Also pay particular attention to your connections. You want quality connectors that are crimped well. You can make your own or buy them in and just connect them.
What type of charger do you have? Factory stuff is usually junk. Replace the Atkinson with something of better quality. I'm running a cheap MorningStar, but there are many other chargers to choose from. The favorite on this forum seems to be Victron. Easily available on Amazon. Also, if you haven't done so yet hook up a battery monitor. I'm using a Trimetric but again most people on this forum use Victron. The battery monitor is a key tool in managing your battery usage and monitoring your solar performance. Well worth the investment.