Help Midnite Solar Classic 150 Experts - Resting not float

If you have GEL batteries... Check the battery manual, but typically GEL batteries should charged at 14.20 volts maximum (typical for GEL type).

You may need to talk with your Midnite supplier (or call/talk with Midnite directly) about debugging your controller (7x36 Vmp panels in series) for your 200 vmax controller.

-Bill

You may have missed my post a few back... Your solar array has too many solar panels in series...

7x is high enough to cause the controller to go into "hypervolt" (shut down when Varray > 200 volts) and damage when Vpanel >~248 volts.

Your array should have no more than 4 (or possibly 5) panels in series... There is the Midnite sizing tool to confirm the correct size array.

http://www.midnitesolar.com/sizingTool/index.php

It is possible that your solar array is not properly connected (you have a "broken" connection or other miss-wiring somewhere)...

In any case, you need to rewire the array for 4 panels in series maximum (perhaps 5, depending on your local cold weather conditions).

Do not "fix" your 7x series string--If you are lucky and there is an open connection, you probably saved your charge controller from expensive damage.

-Bill

Check the polarity of your solar panels... Mixing + and - does occasionally happen.

Another suggestion use Red and Black electrical tape to mark the polarity on your cables.

-Bill

3x series panels will work for testing... Basically, you have to work with the limits of the controller... For example

• 3s x 1p = 3 panels
• 4x x 1p = 4 panels
• 5x x 1p = 5 panels (if OK for your low temperature)
• 3s x 2p = 6 panels
• 4x x 2p = 8 panels
• 5x x 2p = 10 panels
• 3s x 3p = 9 panels
• 4s x 3p = 12 panels
• 5s x 3p = 15 panels
• 4s x 5p = 20 panels (roughly the maximum "useful" size of array)
• etc.

You may have other limitations... Check the manual for your GEL batteries.. .In the USA, we typically see a maximum of 5% rate of charge. Other brands may allow higher charging current.

So, for example, if you have 4x 12 volt @ 200 AH GEL batteries in series with a maximum of 5% rate of charge:

• 200 AH * 56.8 charging voltage * 1/0.77 panel+controller derating * 0.05 rate of charge = 738 Watt "useful" maximum array

If you had flooded cell or AGM batteries, you could support a higher charging current. Say Flooded cell @ 400 AH @ 48 volt battery bank and 10% rate of charge:

• 400 AH * 59.0 volts charging * 1/0.77 panel_controller derating * 0.10 rate of charge = 3,065 Watt array "nominal" for FLA battery bank

We are kind of doing things "backwards" here... You have an existing system that needs to be debugged.

But once you get it running, then I would suggest that we review your energy needs (peak Watts, Watt*Hours per day, location of system for hours of sun, etc.) and make sure you have a "balanced" system design.

You have chosen some very nice and capable components (like the Midnite controller and a good sized solar array)--But have a relatively small battery bank (and possibly limited by GEL battery capabilities). It seems that should be reviewed.

-Bill