Need help with a charging question

[NoobieRV]

I wonder about the difference in voltage at the battery vs at the output of the controller. When you say 12.8, is this the display? If so, put a meter on the actual output. Maybe the display says 12.8 but the sensing voltage is 12.5

Hi Pedro Dog
I have checked and every state the battery is in (charging, not charging) the Batt V on the controller matches the actual V at the battery terminal

 

[NoobieRV]

I note this in the manual:

View attachment 178160

Read literally, it would mean the battery state is only valid while charging. Or, it's a bad chinese translation. There's no other detail to be found, so one either ignores it or does a deep dive to discern if this is strictly a static voltage equals some capacity indicator, there's some smarts like it's based on what point of the charge cycle it's on, it's actually counting Ah, or "other".

Looking further, I see this:

View attachment 178161

Reading through, these are setpoints to initiate charging or operation events. But I wonder if they are also used as thresholds of interpreted state of charge. Don't know.

The way I would approach it is to see if the controller has the proper charge cycle voltages and times for the battery topology I have, then ignore the state of charge. Because a solar controller isn't monitoring loads they tend to make for crappy battery monitors. If one wants to know actual state of charge an Ah counting meter is a better option, and let the solar controller manage the solar end of it. Compared to some, this one appears to have the adjustability and features I would want, so I would run it and see how it does.

Mark B.
Albuquerque, NM

Thank you, this is very helpful and it does seem that the controller icon is only useful when in the charging state, it seems to be full when the controller cuts the charging to the battery and shows in increments toward that 13.8 mark, this is how I would know if the battery is fully charged while charging

 

[NoobieRV]

If you want to get a reliable soc on your batteries install a quality battery monitor and dont go by the charge controller. I would create a custom charge pattern to match the specs from the battery. It isnt likely you will notice any problems but the default setup could be taking substantial time off the life of the batteries and costing a lot of money by having to replace batteries more often. Battery monitors are a lot less expensive than batteries

It is true that I could get a battery monitor, for now I am waiting for a switch board with usb's to be sent and on that is a display showing battery voltage, so that might serve as a good quick check for the time being
I will try to familiarise myself with what the settings should be and I may try to make a custom setting and see if that changes anything.

 

[NoobieRV]

Thank you all for your wise words and for helping me through this dilemma, looks like I have got the answers I came for and appreciate your time in answering
Hope you have a nice day and happy camping!