The discharge current on the charger in the previous link goes up to 5 amps. That's over double the high limit for battery charging. I posted in another thread that 1.5 amps is the recommended charging rate, so as not to burn out the panels, i wrote down the wrong number, it's 1.8 amps. There is actually a formula that depends on the battery's total amperage and how tall it is (stratification) This is for new battery. After much research it was found that automatic chargers which let the battery draw what it can, sometimes starting at 10 amps, shortens the life of the battery. 2 amps is what is become the commercial standard, but if you look at the better charging systems, they are at 1.8 amps. There is an equation for charging based on battery size and ambient temperature. It's on the 2nd link below.
Don't take my word on it, research it. I found this stuff out around 3 years ago, and have noticed that all the batteries I have since purchased, even when I let run dead, charge to full capacity, and seem to hold on to the CCA (Cold Cranking Amps) much better. I notice this starting the vehicles in 10 degree and single degree digits. I stick to two amps for charging my batteries. My Motorhome has a built in charger on the inverter, so I just keep the Motorhome plugged in. The battery is 8 years old now, and works great. Proper charging reduces sulfide, the killer of all batteries.
It does take longer with the lower amps, but battery life is vastly improved. I don't charge anything at 10 amps anymore, unless it's so dead I can get a charging start, then I blast it with 10 amps for a few minutes to establish polarity. I have noticed that some of my automatic battery chargers will show 90% charge when set to auto, but when set to 2 amps, it then reads 75% charged, and this is within the same unit. So companies are selling chargers that have different battery states at different levels of amperage. To me, that's really poor engineering. IMHO.
Interesting articles: Battery Charging Tutorial | ChargingChargers.com
Complete Guide On How To Charge A Lead Acid Battery - Power Sonic
(if you apply Ohm's Law to this, on some instances, you come up with some pretty low amperage charging)