There might be a fuse in the charging station.
A bulletin I found on Google searching for Milwaukee charging station fuse.
TO INFORM YOU
PRODUCT SUPPORT BULLETIN # 474
TO: AUTHORIZED portable electric tool SERVICE STATIONS DATE: January 2008factory SERVICE / SALES SUPPORT BRANCH
TOOL(S) \ PRODUCT(S) AFFECTED: 2601-20 18.0V Li-Ion Compact Driver/Drill
48-11-1815 18.0V 1.4Ahr Li-Ion Battery Pack, 48-59-1801 18.0V Charger
SUBJECT: Troubleshooting Guide 48-59-1801 18.0V Charger / 48-11-1815 18.0V Li-Ion Battery Pack
Symptom
Possible Cause(s)
Solution(s)
Battery Pack connected to Charger, RED or GREEN LED lights failure to turn “on”.
Line voltage too high or too low (or no power present)
Charger temperature too high >212oF (100oC)
Faulty Battery Pack – ‘blown’ FET
Faulty Charger
Remove Battery Pack. Unplug Charger and verify correct line voltage - 90VAC – 132VAC for 120VAC Charger
Allow Charger to cool 3-5 minutes before attempting charge. Power must be removed for a minimum of one minute then reapplied if this condition occurs.
Try known good Battery Pack on the questionable Charger, or try questionable Battery Pack on known good Charger. FET can fail when battery pack is repeatedly over-loaded - under extreme circumstances, the internal temperature of the battery becomes too high or subjected to water.
UNPLUG Charger - high voltage is present at the AC High Voltage Heat Sink - when AC line voltage is applied to the Charger circuit board. Check for ‘blown’ Charger DC low voltage ‘one-time’ output protection fuse F2 with Volt-Ohm Meter and/or ‘blown’ Charger AC line fuse - F1, if fuse F2 checks OK. NOTE: Before checking fuses F1 or F2 unplug the Charger from power source and let it sit for 3-4 minutes before disassembling – this allows circuit board capacitor to self discharge.
DC HEAT SINK SIDE
F2 FUSE
F1 FUSE
Use only a battery operated VOM to perform FUSE continuity test – it may be necessary to pierce / scrap the protective coating of PCB board on end of fuse to obtain valid continuity reading.
AC HIGH VOLTAGE HEAT SINK
48-59-1801 Charger has no serviceable replacement parts.