Hi, thanks for the response. I have mains hookup with a 40amp charger to keep my batteries topped up. I have an inverter to power everything when I'm running on batteries. I think all I need is a way to put the max charge into the batteries (flooded lead acid).
Would I be better wiring the panels separately (with their own charge controller) or together in series ?
Each panel says on the back 8.6a @ 36v
No. You're far better off with them wired together, either in parallel or in series, with one controller. It would make zero sense to have three ten-amp controllers. You could also do parallel configuration without any issues. 36V panels are grid-type, but can be utilized for 12V with a proper controller.
150Ah, usable storage, is not very much - what size inverter do you have and what do you run on it? A typical 1000W inverter would zero-out your battery in just over an hour.
An mppt solar controller will take the 8.6A @ 36V and convert it to charging voltage, generally around 14.5V, so figure you could get max 300W or 20A at 15V. Generally it make sense to de-rate output estimate to about 80% for real-world usage. The factory specs are done at full direct sun with zero angle at 70*F. Your operating conditions are bound to be less ideal.
I doubt you could get 60A out of them, but a controller rated for 150V and 60A would leave you some headroom while providing maximum capacity of your system. Figure about 45A in ideal conditions.
If you're going to stick with FLA, consider 4 golf cart batteries - 2S2P - the big Trojans are pretty nice and have worked well for years. That would give you about 200Ah usable. 12V marine/RV/deep cycle are just so-so for durability, longevity tends to be not so good. But keeping them fully charged goes a long way for longevity.
Lifepo4 is like jet-fuel, but surely at a much higher cost and complexity.
