Raul, you can tell a lot by loading the battery with hydraulic relief and checking the voltage drop at each cell. I'll bet you'll find at least two or more of the cells drop below 2 volts which will severely deplete your battery charge in short time. That's a quick way to check a battery in the field but the proper way to test a battery is at the battery repair shop using a discharge load bank along with very specific criteria for testing. In my opinion poor connections are not very likely. Good luck