The CTEK 3300 has a battery desulphation feature, compact and water resistant.
Dave
Don't bet on the "desulphation" feature on any charger, especially on the ones we can afford.
Once a battery is sulphated, depending on the degree of sulphation, its pretty well done. The trick is to keep it fully charged and it won't sulphate. That means a good battery maintainer matched to the battery type in the off season and a good charging system on the vehicle.
We tested a $1500 fancy smancy charger that is claimed to desulphate batteries...yeah, right. Its a good paper weight.