A Forum run by Enthusiasts of MidNite Solar

Charge Controllers and Clippers => The "Classic" charge controller => Topic started by: Laser-Boy on May 20, 2023, 10:32:14 AM

Title: Charge Controller Gone Awry
Post by: Laser-Boy on May 20, 2023, 10:32:14 AM
Not sure how this forum works. I have a question about the Classic 200. Been in use for 4 years. Today it went to battery over voltage and stopped charging my system. The controller says my battery voltage is 52.3 which is exactly twice the voltage of my battery system...I run (2) 12 volt batteries in series. I reset the system and it still shows the high voltage and won't charge the batteries. Any ideas folks?
Title: Re: Charge Controller Gone Awry
Post by: boB on May 20, 2023, 11:36:59 AM
Oh boy !   This is a new one for me, I think.

In the main status screen, press the STATUS button a few times (5 times ?)  where the screen shows the serial number and the model number and software revisions.  Just make sure the model number still shows Classic 200 and that the nominal battery voltage is 24V.  Everything on that screen most likely have not changed but we'll check just to make sure.

Is the displayed battery voltage almost exactly twice that of your 24 volt battery ?  What could happen is that a resistor has gone open or shorted on the top PCB inside the Classic. I kind of doubt this is the problem but it is possible.

Does the PV input voltage measure correctly ?   Are there any other values, such as temperatures that look wrong also ?

If worse came to worse and it always thinks the battery is double voltage, you 'could', in a pinch, adjust the Absorb and Float voltage to twice their desired set points so the Classic starts charging again.

The only thing I would worry about is that the Classic might start reading correctly again and that wouldn't be good, so I would watch the Classic kind of carefully while charging.

This might get you going until our support team can take care of your Classic in the usual way when something goes wrong since it is the weekend.

boB




Title: Re: Charge Controller Gone Awry
Post by: LilMT on May 20, 2023, 11:08:36 PM
I have had this happen on 250 once or twice.  Both times it happened during unique circumstances where I lost battery power for a brief period of time.

It fixed by rebooting the midnight being sure to power the classic first and then wait 15-20 seconds after power-up to engage the panels.

One of the times it did take two reboots.

Good luck.