relay or isolator

Well you know how long/much you will use. Allah knows I've asked... The last I recall was my reply about the battery(s) lasting 20 minutes at most.... But you have my previous replies about sizing and auto-connecting the isolator whenever the alternator is charging. I might hear back at the first recharge - or whenever the batteries fail - whichever comes first .

So, how are the batteries going? And the system? As I just updated in rfhvhtoo's charging agm battery, I'm curious to see if the batteries lasted. And obviously, if they only need recharging once a month, why bother with them at all? (Noting that I still have no info regarding this "100AH per 1kW output" rule. An idiot? Or a battery salesperson?) Bigger batteries better than a bigger alternator? Choice! (Except as noted of course. )

This is what I did, added 200 Amp relay and a 3-position rocker switch with a led lights to match the factory look. and see at night. 1st Position. Joins both batteries for starting, and then releases the seconded battery. Your vehicle ( Relay) then switches back to the primary battery after start. 2nd Position. (Middle) starts on main battery, and stays on main battery. (2nd battery remains separate at all times. 3rd Position. Both batteries are joined in parallel. Vehicle starts and runs with both batteries. Good if your main battery dies, just throw the switch and jump start you’re self without getting out of the vehicle. Works good for winches and plows or anything that needs extra power. Just remember to switch it back to position 1 or 2 after you turn off the engine. This simple switch can be picking up a good electronic store (not radio shack) for about 12 bucks. Wiring is simple, but comes with no instructions. You can refer to some web sites or better yet. Look here at the12 volt for wiring it up. The Pac Relay is fine. It’s really a White Rogers relay; Stinger is also the same relay. Buy one on any auction for $ $30 bucks or less, Pac is kind of expensive.