Not getting the battery storage I should.

[reflash]

Hi, I'm a first timer here. Best with me as I'm doing this on an old phone.

I have 2 x SLIGC115 batteries being charged by 3 x 100W 12V panels through a TrakMax MPPT 40A CC.

Here's the options on the CC:

0. EQ1. 13.2. 15
1. EQ2. 13.2. 15.5
2. L A 2. 13.3. 15
3. N S. 13.6. 14.3
4. GC2. 13.7. 14.4
5. GC1. 13.5. 14.1
6. PcCa. 13.2. 14.3
7. L A 1. 13.4. 14.6
8. NiCad1 14. 16
9. NiCad2 14.5. 16

L A = deep cycle lead acid
GC = gel cell
PcCa = lead calcium
N S = not specified

I'm currently using #7

The problem is that once the sun sets, I can only draw about 1/2 AH before the battery voltage falls off a cliff. Any suggestions?

[reflash]

One thing I forgot to mention, the first number in each entry is the float voltage, and the second is the bulk EQ.

Would it harm my batteries if I used a higher voltage setting like 8 or 9?