Just a hint to others about a problem we had recently. Batteries were either not charging fully on solar or not giving up full power (aH) ,,, ie "something" was wrong.
The 11 year old solar controller started to charge batteries about 2 amps ABOVE THE VARIABLE LOAD rather than say 7-10amps above the load which was typical, ie it "tracked" the load current but about 2 amps above it.
In short cooked one of 4 batteries, so replaced all batteries without knowing we actually had a serious fault.
Reconnected everything and controller was showing 17 volts charge voltage,,, checked at batteries 16.2v. Disconnected quickly.
New solar controller,,, all good.
Hope this helps others if they see the same problem.
Cheers Baz
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Why is it so? Professor Julius Sumner Miller, a profound influence on my life, who explained science to us on TV in the 60's.
Hi Baz, is it possible you disconnected the batteries from the controller before you disconnected the solar input cables? The symptoms of uncontrolled charging suggest the Mosfet in the controller was punched through and this is generally cause by a spike over and above the tolerance level of that particular mosfet, the result is a dead controller.
T1 Terry
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Hi Baz, is it possible you disconnected the batteries from the controller before you disconnected the solar input cables? The symptoms of uncontrolled charging suggest the Mosfet in the controller was punched through and this is generally cause by a spike over and above the tolerance level of that particular mosfet, the result is a dead controller.
T1 Terry
Have disconnected 4 times before, no problems. Controller wasn't dead,,,, everything else working just charging too high a voltage. Yep open circuited panels before job.
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Why is it so? Professor Julius Sumner Miller, a profound influence on my life, who explained science to us on TV in the 60's.
Thanks Baz, if the battery reached 16.2v the solar was charging directly to the batteries with no interference from the controller. If the solar was disconnected first and reconnected last each time then that eliminates that as the cause of the mosfet being punched through resulting in the controller no longer controlling. Have had the same thing happen with 100 amp solid state relays, same principle but just a much larger capacity mosfet, it is always a serious current spike that punches them through and generally cause by a short to ground either side of the relay causing a huge current spike or the solar still being connected but the battery not connected when a large capacity inverter was connected, the inrush current to the capacitors is huge and is seen as very close to a momentary short circuit and causes a similar effect.
T1 Terry
__________________
You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links
If the solar was disconnected first and reconnected last each time then that eliminates that as the cause of the mosfet being punched through resulting in the controller no longer controlling.
I interpreted the above info as being, If I disconnect the battery from the solar controller, while the solar panel was still connected, there is a good chance of the solar controller/regulator being damaged.
This was something I, (and I assume others), were not aware of, so thanks for that
If the solar was disconnected first and reconnected last each time then that eliminates that as the cause of the mosfet being punched through resulting in the controller no longer controlling.
I interpreted the above info as being, If I disconnect the battery from the solar controller, while the solar panel was still connected, there is a good chance of the solar controller/regulator being damaged.
This was something I, (and I assume others), were not aware of, so thanks for that
Hi
Yes that is correct as Terry points out. I guess it is not common for people to read the manual but they always give this procedure for connecting and disconnecting the regulator/controller. Better quality regs may not be damaged as easily by incorrect connections but they still warn about how to do it correctly.
What is important is when you just need to do a 'quick' job on the wiring. I have fallen for that and disconnected the battery wire but have got away with it after a reboot in the correct manner.
-- Edited by Jaahn on Friday 27th of July 2018 07:39:52 PM
I have a CTEK D250S Duel, DC DC Charger, what Ctek call a professional battery management unit It takes both solar panel, and engine battery/alternator power, and regulates it before sending it to the house/leisure batteries
I have just read the PDF manual, and unless I have missed it, or if it is written in electrical speak It does not seem to mention that we should disconnect the solar panel, before we disconnect the battery
But I will now remember the advice, of both yourself, and T1 Terry
