[suicideneil]

Your loader? You mean charger?

It sounds like if the voltage is too high you have it set for 2s when you plug in the 3s pack?

Do you have it set for lipo, and not li-ion/ life etc?

Use a voltmeter to read the cell voltages/ whole pack voltage.

Normally low-voltage is the issue with chargers, but thats easily fixed ( if its fixable, that is )...