CTEK Battery Chargers

[wayneskid]

Has anyone had experience with any of these chargers? See
CTEK Battery Chargers | The World's Smarter Battery Charger for the full line of models. I bought the Multi US 7002. I've been reading the documentation and haven't connected it yet. My Interstate will be in long term (indoor, heated) storage in Oregon this winter and I think I will use this one for the coach batteries and perhaps get the cheaper Multi US 3300 for the Sprinter battery. The FAQ page says you don't need to disconnect the battery when charging with these models but I'm wary. Any thoughts from the forum would be appreciated. For those that have their vehicles in long term storage during the off season, what do you do to keep the batteries up?
Thanks,
Wayne

[bryanl]

The manual says "The MULTI US 3300 is a primary switch mode battery charger with pulse maintenance" -- that 'pulse maintenance' is key here because it claims (1) the device is designed for battery maintenance and (2) uses a desulfation technique which will help reduce a typical source of battery aging. It also has a maintenance mode indicator which should be used to make sure that the battery and the charger can settle down for maintenance operation.

The website also claims that the device limits charging voltage to protect in-circuit devices. This is another key feature needed for RV use. I think the 7200 voltage is a bit high but the 3300 is well suited for RV needs.

The manuals look to be pretty good as well with good cautions and caveats and straightforward information.

The biggest downside I see is that they do not provide much charge current which puts them more into the 'battery maintenance' category than battery charger or RV power supply.