2003 ls 430; went to charge battery, now no power, fuse?

[Robert Grant]

put charger on battery ; tried to unlock rear door, discovered no power; no horn

[Lexus_DK]

Did you hook up the charger to the wrong terminals of the battery? Maybe you killed the battery or fried an ecu 

[Robert Grant]

problem fixed;battery was all the way down;replaced bad alternator - everything ok