MPPT operation

[MrNatural22]

Good morning all, can someone explain what might be occurring
in the morning on my 4215bn
CC readings. 3-100w 12v panels in series. 12v LiFePo. Sun is shining on the panels at 8am. PV input voltage on the MT50 meter reads only 14.8v at this time.
If I disconnect then reconnect the panels the voltage jumps up to 61.4v and remains. Don’t understand is this normal operation?
If I do nothing, the voltage does eventually rise as the sun gets higher.
Is this a normal function?
Anyone else notice the same thing on theirs?
Can someone explain what is happening?

 

[gnubie]

Without checking the spec sheet for that controller it could well be that the unit is staying in non-MPPT mode until it sees high enough panel voltage to justify switching to MPPT mode to optimise power into the battery under lower light conditions. If you leave it alone and watch the voltage rise up as the sun gets higher, does the voltage increase significantly if you disconnect / reconnect the panels and wait a minute for the controller to settle down again? If it doesn't don't worry about it, likely everything is working fine. If it does jump up significantly the controller might be getting stuck on a knee in the current / voltage curve thinking it has hit MPPT but hasn't. A firmware update may be needed.

I have heard of epever charge controllers getting stuck on a less than optimal position but haven't had enough experience with them myself to know if that's a valid concern or not. I did test an epever for a remote project but didn't see that problem myself.

 

[MrNatural22]

Without checking the spec sheet for that controller it could well be that the unit is staying in non-MPPT mode until it sees high enough panel voltage to justify switching to MPPT mode to optimise power into the battery under lower light conditions. If you leave it alone and watch the voltage rise up as the sun gets higher, does the voltage increase significantly if you disconnect / reconnect the panels and wait a minute for the controller to settle down again? If it doesn't don't worry about it, likely everything is working fine. If it does jump up significantly the controller might be getting stuck on a knee in the current / voltage curve thinking it has hit MPPT but hasn't. A firmware update may be needed.

I have heard of epever charge controllers getting stuck on a less than optimal position but haven't had enough experience with them myself to know if that's a valid concern or not. I did test an epever for a remote project but didn't see that problem myself.

Thanks gnubie, It does rise up to 57v-62v as the sun gets higher on its own if I leave it alone. And it is producing a charge at that initial low voltage of about .7a from the panel and 1.5a out from the MPPT from that 14.8v Which also rises as voltage rises. I was just playing with it and did the unconnected/reconnect of the panels. Other wise it does a fine job of quickly recharging the LiFePo back up. I'm trying to gain an understanding of the MPPT operation. Learning alot of new knowedge on this forum.
As for a firmware update would I have to have the EPever program on my computer? I do have the PC software communications cable but after trying to download the very cofusing software I gave up. I do remember Will Prowse stating it was for advanced users, which I admit, I am not and complicated computer downloads only boggle my brain. Is there a different way or method to update the software of a EPever 4215BN CC?

 

[gnubie]

I'd like to answer that question but I'm a linux boy so I don't really live in the Windows world. I have downloaded the Windows program and read the PDF that comes with it, and that is a bit messy and it doesn't mention how to update the firmware. I think you are best to leave it alone since the controller does appear to be working OK.

My main experience with controllers is with Victrons. The Victron program itself is bundled with the latest firmware. Update the program and you get the new firmware too and it's then a few simple clicks to update the firmware in the controller itself.

 

[MrNatural22]

Like the wise adages we all know as lessons learned "If it ain't broke leave it the hell alone" or "Curiosity killed the charge controller"
OK I may have embellished a tad bit on those-- LOL ???