Lithium battery chargers - not kicking out enough volts

[Joe Shmoe]

Hi,

I have two lithium 36v batteries and two charges, made especially for said 36v batteries.

Both batteries are good and one of the Chargers is able to bring them both up to a charge of 41.9v..... Makes sense as it says 42v on the back of the charger. I measured the output of the first charger by sticking a multimeter on the pins of the output connector, and it measured 41.9v. All good so far.

The other charger seems to have a problem as it wasn't charging the batteries fully and testing the output at the pins of the connector that goes into the battery, it only measures 26.7v???

Any ideas why this would be and can I fix it somehow?

 

[Myfordman]

Most are switch mode power supplies nowadays and the most common fault with these is failure of the high voltage reservoir capacitor.
Fit a replacement with as low an ESR as you can find that will fit.