So SwaintaN, to answer your question about your battery, it is probably hissing or making some kind of boiling noise because it is venting. Although you didn't mention what kind of battery you have now specifically, I presume it is some kind of maintenance-free battery. When batteries vent while on a battery charger, it is usually because they are overcharged. Once that electrolyte leaves the battery, there is no replacing it. That doesn't necessarily mean the battery is bad, but it does mean the lifespan of the battery has probably decreased to some degree.
If your battery charger is not properly-regulated, it will keep delivering current to the battery even after it is fully-charged. Since you mentioned jump-starting your Ex, I should also caution you that jumper cables are the electrical equivalent of a one-gallon gas can. They can get you started and to your next destination, but you should really fully-charge any battery that needs a jump with a battery charger as soon as possible, just like your next stop after putting one gallon of gas in your empty gas tank would likely be a gas station.
I read through the whole thread, but didn't see any mention of your typical driving habits. If you are jump-starting your truck and only driving for about 10-15 minutes or less, your charging system probably doesn't have a chance to fully-charge your battery. Most alternators are designed to maintain voltage, not recharge deeply-discharged batteries. Asking that task, even of a high-output alternator, can lead to a cycle of dead batteries and jump-starts, until either the battery or alternator fails.
It looks like it has been at least two months since you started this thread and from what you've posted, it sounds like you've been dealing with these issues even longer. At some point, it may be worth evaluating what your time is worth to you and if you might not be better off spending a few bucks to have someone else sort these problems out for you.
Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
www.fb.com/optimabatteries