Battery charger with negative disconnect

[challenger_affair]

How do you charge a battery while its in the vehicle, while using a negative battery disconnect? 

I have a Battery Tender Plus 1.25 Amp charger and since I don't drive the car daily I would just always leave it connected to the battery and its been great.  Recently I installed  a negative disconnect on the battery cable in order to keep from draining the charge and protect against corrosion of engine parts.  So now I would like to just connect the charger directly to the battery.  But the instructions indicate you aren't supposed to connect the NEG directly to the battery.  Has anyone successfully bent that rule?   

[tman]

I use the Tender all the time connected to both batt terminals.  In fact, when they give you the connectors that are permanently attached to the battery, they are attached to the terminals. 

[challenger_affair]

OK, good to know.  I noticed those connectors and figured it wouldn't be an issue since that's what they supply, but then I looked at the instructions and it said something different...  That'll teach me