Solar voltage help...

My old controller got messed up when I was swapping wires around and did something wrong not sure what, but-- after that it would still charge the batts when all hooked up but the voltage went up higher than the high set point.

That controller manual says if the voltage went way high (16-20v) it was from an "open FET" and if voltage was way low (2-5v) it was from a "shorted FET"

An open FET fault will overcharge the battery. Either way, the controller is toast if it's defective FET

OregonTRX4 wrote:
input to the controller and output to the batteries measure about the same at 21.xxV at the controller. So is it most likely the controller is bad?

Yes. Sounds like the controller is running in 'pass thru' mode, which no controller should ever do.

OregonTRX4 wrote:
It isnt built in just attached to the frame behind the pannels i can attach any other controller I imagine.

Do it.

Almot wrote:
If it starts from 13.9 with controller connected to battery, and goes to 16, then this built-in controller is either bad or is not wired properly by the manufacturer, or is stuck in Equalize mode (if it has such a mode). In either case this is bad for battery.

I never liked those kits with unknown controllers.

I posted the controller. It isnt built in just attached to the frame behind the pannels i can attach any other controller I imagine.

If it starts from 13.9 with controller connected to battery, and goes to 16, then this built-in controller is either bad or is not wired properly by the manufacturer, or is stuck in Equalize mode (if it has such a mode). In either case this is bad for battery.

I never liked those kits with unknown controllers. For this one they don't even provide any specs other than "a built-in controller with 5m alligator clips". Welcome to era of China.

Tom_M wrote:

OregonTRX4 wrote:
Measured at batteries. It is disconnected.

What is "It"? Was the voltage measured at the battery when everything was connected? It would be impossible for the battery to measure 16.55 if it is disconnected and very unlikely even when connected unless the battery is bad.

With everything connected it starts at 13.93 and ramps up to to 16.xx before I disconnect the solar from the batteries. Batteries measure 12.6 shortly after panels are removed. It is doing this on multiple batteries. The input to the controller and output to the batteries measure about the same at 21.xxV at the controller. So is it most likely the controller is bad? I tried connecting batteries to controller then controller to solar and it made no difference. This is what I have http://www.solarblvd.com/Solar-Panels-&-Systems-12-Volt-Solar-Panels/c1_269/p2754/W-Solar-160-Watt-Foldable-12-Volt-Solar-Panel/product_info.html

Tom_M wrote:
It would be impossible for the battery to measure 16.55 if it is disconnected and very unlikely even when connected unless the battery is bad.

Yes. If everything is disconnected from battery, it can't measure 16.55V, so the meter is faulty then. It is possible for battery to measure 16.55 when controller that is either faulty or is in Equalize mode is connected to it (and the panel is connected to controller, naturally).

Btw, what battery or a set of batteries we are talking about? A pair of 12V in series ;) ?

OregonTRX4 wrote:
Measured at batteries. It is disconnected.

What is "It"? Was the voltage measured at the battery when everything was connected? It would be impossible for the battery to measure 16.55 if it is disconnected and very unlikely even when connected unless the battery is bad.

Did you connect to the battery first, then connect solar panel?
Seems like it might have been tricked into 24v mode.

Tom_M wrote:
If it is the voltage measured at the battery, it's too high. If it's the voltage going into the controller from the solar panel it may be normal.

:) Exactly.
Where did they measure this voltage - on the battery or on the controller input?

If on the battery, then the meter is faulty, or the controller is faulty. Disconnect battery immediately.