Doubling battery bank question

[Grenadiers]

I have two brand new Lifeline GPL-4DL 12v batteries wired in series for 24v. They are 210ah a piece, so 210ah total in series. I'd like to add two more batteries totaling 420ah. We have 320 watts of solar power, with generator/shorepower backup utilizing an Iota DLS-27-40/IQ4. I connect the Iota directly to the batteries via a short run of 4ga wire connected to welding clamps. Just attach and plug in when needed. So, the question is, regardless of winter/summer sun, would 320 watts of solar panels be enough to charge the batteries? We run about 50ah each night for CPAP, and fridge, adding in an iphone plugged in, ipad for awhile, LED lights nominal. When we have the Truma Combi E, furnace/hot water heater running, you can add 3.9-7.8a and 1.1-5.6a. Anyway, our trip to Baja in January I had to run the very loud generator once in awhile. So, without too much over my head details, on any given day, would 320 watts of solar be sufficient? I'm also thinking of adding an ACR unit between the two 4d starter batteries and the Lifelines. Thanks, Dave

 

[dwh]

Input vs. Output

If the input (solar) and the output (loads) doesn't change, then doubling the size of the battery bank only doubles the time between generator runs - it doesn't change the net negative of input vs. output.

 

[dwh]

In other words, if you put 40ah in during the day and draw 50ah out at night...the bigger bank will last twice as long, but will still end up needing to be charged with the Iota.

 

[Grenadiers]

That's what I thought with the current solar panel setup. However, would it make much of a positive difference if I added more solar power? Less generator activity perhaps? I have room for two more panels on top. I don't know which type of panels on top, they are a dark blue, most likely the poly version. Can you mix and match with the mono?

 

[Joe917]

You are probably better off spending the money on more solar. Your existing bank is big enough to handle your current loads. More solar will bring it up to full charge faster and more often, extending battery life.

 

[Grenadiers]

Bought two 160 watt solar panels today. And two more Lifeline batteries. Thanks for all the help. Results once installed will follow!

 

[dwh]

Will your charge controller handle double the solar?