Help Setting Charging Amperage on Trace 4024 inverter

I don't know the equipment... But frequently the charging current is defined as Amps of AC current limit...

Say you want a maximum of 75 Amps of 24 VDC current... That would be roughly (assuming 120 VAC unit):

• 75 Amps * 29.0 volts charging * 1/0.85 AC charger efficiency * 1/120 VAC nominal = 21.3 Amps @ 120 VAC max input charging current draw

So, you set the Max AC input or Max AC charging current to ~20 Amps maximum--The screens sometimes are not very clear on what some of the settings acutally are (XX Amp limit at 120 VAC max input or 24 VDC to battery, etc.).

If you do not have one, I highly suggest you get an AC/DC Current Clamp DMM. You can measure the battery voltage and battery charging current and see what the heck is happening. Is the unit falting on excessive charging current, is the battery bus voltage too high (over ~29.0 volts for normal absorb charging Flooded cell lead acid battery bank), or even too low. What is the charging current when it faults? etc..

A couple of links to look at:

https://www.amazon.com/gp/product/B019CY4FB4/ (mid priced meter)
https://www.amazon.com/gp/product/B0772FYF5M (lower cost meter)

Note, there are AC only Current Clamp DMMs too (that also measure DC voltage, but cannot measure DC current). You have to read the details about the meter to makes sure it is an AC+DC current clamp meter, and not an AC only current clamp meter. Either type of meters are very good to have... But for our DC battery bus/solar power/etc..., having a DC capably clamp meter is very nice to have, and very safe to use (just clamp on one wire to measure current--No cutting wires and putting in a current shunt to measure current for testing/understanding your system).

The fact that your system is not charging stability seems to be a functional problem, and possibly not just a charging current limit setting. Doing a bit of diagnostics and seeing what the DC bus voltage and current is when it is charging and faulting.

Do you know "the batteries are good"? For older battery banks, they do eventually sulfate and lose capacity... A sulfated battery may seem to charge very rapidly, drop into float, then fall back to a lower voltage (or if there are some DC loads cycling) that knocks the charger back into bulk/absorb.

-Bill