Battery charger

[Bernie/MA]

How would you test a battery charger to see if it's working? Either it isn't or I have 2 bad batteries that won't take a charge.
 

[Ted in NE-OH]

Measure the battery voltage with and without the charger connected. The voltage should be higher with the charger connected.
 

[Uncle Ernie]

Crude way is to tap the leads together to see if they spark!
Put a voltmeter on the battery before and as it is charging and see if the voltage goes up. Same voltage both times? Bad charger. Higher voltage with the charger on? Bad battery.
 

[RayP(MI)]

Drop an ammeter in line with one of the leads, should show a current, depending on state of charge of the battery. Some current should flow even on a fully charged battery.
 

[El Toro]

Does your charger have an amp meter? Both of mine do and show the charging amps. Check the specific gravity of each cell using a hydrometer. A fully charged battery should read
in the 1.275 range or better. 1.100 indicates a dead cell. Hal
 

[teddy52food]

Add a good battery of the same voltage in parallel with the one you are trying to charge. Sometimes those new smart chargers won't work if the battery isn't just right.
 

[dave2]

positive clamp on left ear and negative on the right or tip of the tongue and turn 'er on..........