LI-ION Cell Charger HELP!

[XMA]

okay so I've got this Li-ion charger and the weird thing I don't understand is, that the charger shows that the battery voltage is at 4.19v, but when I go and measure the cell with my multimeter it shows 4.26v? what is happening here? my guess is that the charger is showing the voltage under a load or something. while the multimeter is showing it on idle without load resulting in a higher voltage. or my cheap Chinese multimeter is trash.

also for some reason, it's taking forever to reach 4.20v.

[soubitos]

okay so I've got this Li-ion charger and the weird thing I don't understand is, that the charger shows that the battery voltage is at 4.19v, but when I go and measure the cell with my multimeter it shows 4.26v? what is happening here? my guess is that the charger is showing the voltage under a load or something. while the multimeter is showing it on idle without load resulting in a higher voltage. or my cheap Chinese multimeter is trash.

also for some reason, it's taking forever to reach 4.20v.

Which charger are we talking about?
What multimeter are you using and is it at all reliable/tested against known voltage or reference multimeter?
Taking forever to terminate charging sounds more like aged cells to me or low quality cells.
Of course it all depends on the charger too, charge current and other factors

[XMA]

Charger is a VONTAR ZL220C
Multimeter is a A830L

These cells are from laptop batteries, so its probably because of its age.

[KL27x]

the charger shows that the battery voltage is at 4.19v, but when I go and measure the cell with my multimeter it shows 4.26v? what is happening here?

This is just calibration error unless proven otherwise. And why would you think otherwise?

also for some reason, it's taking forever to reach 4.20v.

It might be due to age that they will no longer hold a float voltage of 4.20. But how long is long? When the battery is at 4.19V, there's only a hundredth of a volt trickling an itsy charge current into the battery. The last 1% takes really long. Most chargers will just cut off when the charge current drops to an arbitrary trickle and turn on the green light, "bing." You don't need a green light to tell you when it's done charging. You have a voltage display. When it's high enough for you, it's done charging.