Don't waste your time or money
Battery desulfation has become a cult area. Dozens of circuit designs, home-built chargers/desulfators, many commercial
products with or without chargers, dozens of "testimonials", hearsay, etc.
One guy complained (bragged?) that his super-duper home-built de-sulfanator made his TV cut out :-)
However, to my knowledge there has been no scientifically rigorous testing which supports the many claims. There has been scientifically rigorous testing (by a U.S. nationally known testing laboratory) which found no benefit.
I was involved in the testing of 10 such devices by different manufacturers. Together with two expert colleagues, over a period of almost 2 years we tried to show the benefits of de-sulfators in testing according to a pretty good protocol we had designed. Result: virtually no benefit from any of the devices tested.
However, we did find that equalization
of flooded batteries (T-105s in the test) indeed DID result in capacity gains. In fact, just one episode of equalization showed more improvement that the sulfation treatments had shown in a year or more.
Additionally, I found with my own 10 T-105's (8 on the boat, 2 in my home ham shack) that floating them at 13.8VDC in 70F ambient temp and periodically kicking them up to 14.8VDC for 30 mins or so made a significant difference in both their capacity and their longevity.
Best advice IMHO:
- Use them (in new batteries, it takes many discharge-charge cycles before they reach full capacity).
- Don't routinely discharge them below 50% capacity (12.2VDC resting voltage).
- Charge them at 14.6-14.8VDC.
- Float them at 13.6-13.8VDC.
- Frequently, kick them up to 14.6-14.8VDC for an hour or so.
- Keep them watered.
- Keep them clean.
- Be careful not to introduce contaminants when checking or watering.
- A few times a year, equalize them at 15.5VDC for a few hours.
- You should get 6-9 years from good flooded deep-cycle batteries before their capacity falls to under 80% or so.
Note that claims like, "I got 12 years from my house batteries" very often mean little or nothing. That's because what's acceptable in one situation may not be in another, and most persons making those claims have no idea what the actual capacities of their batteries were in the months before failure.
Hey, your 6-year old car battery is "good" because it started your car this morning. But, it may not start your car tomorrow....or even this evening....because it's lost
capacity every day since you had it installed. How much? You can only know that by load testing with either the 20-hour fixed load method or by use of a sophisticated tester such as Maine
Sail referred to (which he and I have come to rely upon).