Solar Panels Brands - does it matter?

Any issue with charging an AGM slower will be on a sliding scale. A few amp low will not have the capacity fall off a cliff. The issue will be if you get 9.5 years out of them or 10 years.
JMHO. Contact Lifeline for best answers.

Just missed fitting the Fullriver DC335-6. Too bad, they would be awesome.

Thank you for the discussing the pros and cons of the 45 vs 60 amp controllers. I appreciate all the input and discussion. I am inclined to have flexibility to expand, so will go with the 60.

Thanks Almot for emphasizing the shading issue. I should be able to install at or better than the distances you mention.

The concern about negatively affecting the 6v Lifeline battery life is problematic and a surprise to me given how well recommended Lifeline is in these forums. In my situation, it is the highest amp hour AGM battery I could find that fits my 2 battery trays. I need to stay less than 11x8x14 for individual battery size. I was considering (2) 6v Fullriver 250 amp hours batteries, but that is 50 amp hours less.

If charging current for 300 AH is less than 60A, they warn that "... the cycle life of the battery may be negatively affected".

With 600W array in a bulk mode in absence of loads it will be 40A at the very best. So... what the manufacturer says...

Lifeline calls for .2C or 60 amps for 300 amp/hrs.
Your 35 to 50 amps should be fine.

IMO the real issue is don't trickle charge at 5 amps because you will hang up in absorption too long. Also lead-acid likes to be charged so a slow rate leaves the battery discharged too long.

Use the charging manual to set the voltage points.

Manual see page 19

steveexplorer wrote:
We measured the roof and I can easily fit (2) 24v 300 +/- watt panels up there for starters.

So based on what I learned here I will be starting with (2) 24v 300+/- panels (600+/- total watts) with MPPT 45 or 60 amp controller to (2) 300 ah Lifeline 6v batteries (total 300 ah) to 2000w inverter?? Probably need to include a battery meter as well.

1) Shading - as somebody (SMK?) mentioned, make sure the panel is at least 16"-18" from the A/C unit, especially aft of the A/C where it's steeper, and at least 10" from lower structures like vents. Panel may "fit" but it may shade. Not everybody does this, but wherever possible, try driving those deck screws in panel mounting brackets into rafters, not just into plywood. The first rafter from the A/C is - usually - 16" or 18".

2) MPPT 45 should suffice, though 60 will give more margin for when you run some devices at the same time with charging (too long to explain).

3) Not sure about 6V Lifeline. Good brand but I recall in their manual that for longer life you should charge it at certain minimal charging current, and this minimal current is much higher than with other batteries brands, in fact it is so high that RV solar can't provide that much. In other words, they are not made for RV solar. At least, this is so for their 12V models.

4) Either battery meter or an optional remote controller monitor (this would be cheaper). Remote temperature sensor and voltage sense wire you'd better get with this controller, whether it's optional or not (I think with Morningstar both are optional).

Morningstar TS-MPPT-45

Maximum (STC) PV Input = 600 watts @ 12 volts nominal
(when using Standard Test Condition ratings)
Your panels will rarely operate under these conditions.

Maximum (NOCT) PV Input = 800 watts @ 12 volts nominal
(when using Normal Operating Cell Temperature ratings)
Your panels will more likely operate under similar conditions to this rating.

So if one is not contemplating expansion of PV panels more than 600 watts a TS-MPPT-45 will work well.

Again, at nominal 12 volts (batteries or system) the maximum PV array input rating for the TS-MPPT-45 is 800 watts when using Normal Operating Cell Temperature ratings which is more like real world conditions than the standard test.

Perhaps a typo? The maximum array watts for the MPPT 45 is 600W, not 800W.

The MPPT 45 will handle 2x300W panels but it may derate depending upon the panel output. I agree with KJINTF that for 600W panels a larger controller would be less taxing on the electronics and allow for future expansion.

Eso

Sometimes the specifications are a bit difficult to understand
Good to see you figured it out

The RV industry is only a small fraction of Morningstar's business
Check out the newest line to their MPPT controllers a 600Vdc input MPPT controller YES full 600VDC not their standard 150Vdc but 600VDC - Telcom and residential markets have been looking for something like this for a long time.

The Battery does indeed power the controller and is typically connected first so that is can sense the battery operating voltage be it 12, 24, 36, or even 48Vdc. RV's use 12Vdc which is the least efficient operating voltage of them all the reason why many residential systems and most if not all Telcom systems use a 48VDC battery.

Sure two each 300watt Voc=24 volt panels will work great with a 45amp controller either in a parallel or a series configiration - only thing is that the system is maxed out from the beginning - for me that's a POOR system design. It's done many times and works for some folks however not something I would design or promote.

I have 560watts and can easily get in excess of 40amps from my 60amp controller to the loads - Quality panels, cool weather and direct sunlight you should easily see the full ratings of the panels. If not something is WRONG with your system. Now if you are in Arizona in the summer that's a different story.

http://www.morningstarcorp.com/en/support/library/MPPT-Primer2.pdf
See pages one and two. I stand corrected regarding Nominal Maximum Input Power Ratings as it relates to battery volts and not PV panel array volts. However, I also stand by my assertion that a TS-MPPT-45 will work well with two 300 watt, 24 volt panels. Again, at nominal 12 volts (batteries or system) the maximum PV array input rating for the TS-MPPT-45 is 800 watts when using Normal Operating Cell Temperature ratings which is more like real world conditions than the standard test. And in those real world conditions it is likely that one would never approach the Maximum Solar Open Circuit Voltage of 150 volts DC. I agree with scroller95969 that the Morningstar specifications are confusing.