Question about a lead acid charger to be used on li-ion

[brone]

Hello,

Being super cheap I don't want to purchase another charger. I have this "Wate" charger that states it's for 24V lead acid batteries 15A.
I want to bump up the voltage to 42V5A for my liion pack ( already tried turning the adjustment pot to 42V and meter shows it can reach it ).

The question is about the cut-off pot (cut-off voltage?) adjustment - I know lithium chargers bumps down the amps when it's near full, how do I test and know that the adjustment is correct?

 

[brone]

This is the image i found on their website, so Im guessing this charger is unusable for liion since the voltage drops off near full? (image on the right is for lead acid charger)

 

[Steve4]

A charger designed for lead acid batteries has a float charge mode, which is not suitable for Li-ion batteries, as they do not need to be maintained after a full charge. This can lead to overcharging and damage to the Li-ion cells.
You can try adjusting the potentiometer to set the correct voltage (42V for a 10S Li-ion battery), but controlling the current drop as it approaches full charge, as in the left graph, is a critical factor that the charger should automatically perform. If you can set the device to accurately reduce the current when it reaches 42V and complete the charge, then it is usable. However, without precise adjustment and testing, this can be risky. use a multimeter to measure the current and voltage during the charging process. The current should begin to decrease when it reaches 42V. If the charger continues to supply constant current after reaching 42V, it may cause overcharging and damage to the battery. If you are not sure of the exact setting of the charger, it is better not to use it, the battery may overheat or explode.

 

[brone]

A charger designed for lead acid batteries has a float charge mode, which is not suitable for Li-ion batteries, as they do not need to be maintained after a full charge. This can lead to overcharging and damage to the Li-ion cells.
You can try adjusting the potentiometer to set the correct voltage (42V for a 10S Li-ion battery), but controlling the current drop as it approaches full charge, as in the left graph, is a critical factor that the charger should automatically perform. If you can set the device to accurately reduce the current when it reaches 42V and complete the charge, then it is usable. However, without precise adjustment and testing, this can be risky. use a multimeter to measure the current and voltage during the charging process. The current should begin to decrease when it reaches 42V. If the charger continues to supply constant current after reaching 42V, it may cause overcharging and damage to the battery. If you are not sure of the exact setting of the charger, it is better not to use it, the battery may overheat or explode.

Thanks for the input. I don't really need the 3rd phase of the charging anyway cause I dont charge the batteries fully so I may just turn the 3rd screw to the lowest so the charger can shut down whenever it reaches the 3rd phase

 

[rafalg]

if the voltage is set to 42v then you should be ok, as long as the current is not above your battery limits. Measure it when charging.
If it's 15A and your battery can only be charged with 5A max, then no good. I dont know your charger model, but for me it looks like it should have a current adjustment knob, not voltage adjustment.