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
swamp said
05:05 PM Jul 24, 2018
Hi
sounds like it was going into a recon / desulphation mode . glad u worked it out .
T1 Terry said
03:19 PM Jul 26, 2018
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
Baz421 said
04:45 PM Jul 26, 2018
T1 Terry wrote:
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.
T1 Terry said
05:07 PM Jul 26, 2018
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
Tony Bev said
05:10 PM Jul 27, 2018
Thanks for the following information T1 Terry
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
Jaahn said
07:39 PM Jul 27, 2018
Tony Bev wrote:
Thanks for the following information T1 Terry
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
Tony Bev said
01:22 AM Jul 28, 2018
Jaahn Thanks for that info
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
Hi all
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
sounds like it was going into a recon / desulphation mode . glad u worked it out .
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.
T1 Terry
Thanks for the following information T1 Terry
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
Jaahn
Thanks for that info
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