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Alison Ely asked

Charge controller not functioning properly

We have a Victron Solar Blue 100/30 charge controller. Four pv panels provide between 30 and 38 volts (depending on time of day according to the electrian). The charge controller LEDs have stopped functioning and not sending excess power to float. We have dismantled the system to stop the batteries over charging. We are very remote and totally off grid. The installer (via phone) is claiming that there is not enough volts coming from the panels which is why there is a problem. We think the charge controller is damaged/broken. Advice please...

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Alexandra avatar image Alexandra ♦ commented ·

I think we would need a few more details before it can be said definitively what has happened. What is the system voltage 12 or 24V; if it is a 48V system then the mppt will not charge as the panel voltage is lower than system.

Also what panels are they and how are they connected? 2 in series and 2 in parallel?

https://www.victronenergy.com/upload/software/VE-MPPT-Calc-3_4.xlsm the Victron calculator sheet may clear up whether there is a configuration problem with the setup. You will probably need to input the second sheet with your panel details such as Voc and Imp.

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Alison Ely avatar image Alison Ely Alexandra ♦ commented ·

It's a 24v system. No idea the panel size but believe them to be 100w arranged (apparently) in series and in parallel. I do not really understand how it can be a problem with the panels as it has been working fine for over a year.

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Alexandra avatar image Alexandra ♦ Alison Ely commented ·

So panel voltage will be enough to wake the controller when there is enough light on a 24v system. As you know it was working. We just need to work out what changed.

If there are no lights on the system then it probably is dead. It should at least have a bulk led light flashing if it is in standby mode. If there is some life you can try update the firmware. If it does not accept the update then there is a serious issue and may need to be replaced.

Has there been lightning in the area? Even an indirect hit can affect them if the strike is close enough and the array grounded?

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Alison Ely avatar image Alison Ely commented ·

Thanks for that information. There's been no lightening but the problem occurred on a very hot day (35C in the shade) so I don't know whether that had anything to do with it? It is gratifying to know that it is nothing to do with low voltage coming from the panels. I'm afraid we have been very badly treated by a number of installers and it seems this installer is no better and, knowing we are pretty ignorant about solar, is coming up with spurious reasons why his device failed.

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klim8skeptic avatar image klim8skeptic ♦ Alison Ely commented ·

Given the mppt is a bluesolar unit, and there are no led indication, the first step would be to check the pv array.

Possibly a fuse or circuit breaker has failed in the heat.

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Alison Ely avatar image Alison Ely klim8skeptic ♦ commented ·

Do you mean that it is unlikely to be the charge controller? Why? The voltage at the time the electrician measured it was 30 from the panels and 30 from the controller and he thought this was within the correct range. The problem is that the controller is not regulating the voltage so the batteries could potentially cover charge. I don't have any understanding, apart from the very basic, of how solar power works and to me it should be straightforward. If the charge controller has been working and regulating the voltage and then suddenly it doesn't, then surely the problem lies with the charge controller if the voltage from the panels is within the correct range?

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ejrossouw avatar image ejrossouw Alison Ely commented ·

Hi @solarafrica. The challenge is that without VRM or a connection to the mppt, it is difficult to know what is going on inside it, reset it or otherwise. Also, only a LEDs may have failed, but the controller could actually be fine although two LEDs failing is highly unlikely. INFO - A charge controller requires a higher startup voltage of bat V +5, but then only +1 to keep going It however did work before so is unlikely the problem. Under the circumstances, I'd think the installer should hook up to the device and properly assess it's state as would be required for an RMA. All being said, if a key indicator light on a unit that has no other means of displaying status failed, a warranty claim is totally justified. It is an integral component for its correct operation.

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Alison Ely avatar image Alison Ely ejrossouw commented ·

Not sure I understand you.... VRM and mppt? However if there is 30v coming from the panels (and this is early evening - 38v during the day) then this is more than the battery voltage +5. Also there are 3 LEDs on the charge controller - none of which are working. The electrician comes again at midday tomorrow to do more tests. So if any of you have any ideas what else he can do, all suggestions gratefully received. Thanks for all the comments.

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klim8skeptic avatar image klim8skeptic ♦ Alison Ely commented ·

Mppt = charge controller.

The early "hardware revision 1" charge controllers were powered from the PV array. No leds on would indicate no solar pv voltage.

The later "hardware revision 1.5 (and above)" controllers could be powered from either the pv, or the battery.

Check your mppt sticker to work out which version you have.


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ejrossouw avatar image ejrossouw klim8skeptic ♦ commented ·

@klim8skeptic Good info and to know as I typically never install anything that is not programmable or remotely accessible. Even my completely off-grid installation is GSM connected ;) That however being said, I appreciate Victron has its roots in robust marine solutions where it could be a luxury.

@Solarafrica I personally think you have already proven there is enough power from the panels. After confirming the info @klim mentioned, I still suspect all an electrician can prove is that there is enough power going in and it is also going out. He can also verify the batteries are in a healthy state. The Victron equipment has to be looked at by someone with the charge controller knowledge and how to set it up if it has the option. I'd be worried if not as even the most basic PWM charge controllers require some configuring to differentiate between battery types. For the time and money invested in fault finding so far, it could probable already have been replaced. I wish you success, but do think the reseller/installer should own up to his responsibility, especially if he installs a highly reputable brand such as Victron.

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Alison Ely avatar image Alison Ely ejrossouw commented ·

Thank you all for the information. As you can see I am a complete novice (picking up knowledge each time something goes wrong with the system! ). We have a very basic system being very remote and living on the seashore. Everything you have said points to the fact that the installer is trying to backtrack (after all he installed both the charge controller and batteries so should know that they needed to be compatible). I hope, as you say, that he will replace the controller and we can get back to normal service again. Are there any forums as helpful as this one where I can get general advice about non-Victron solar power products??

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ejrossouw answered ·

@Solarafrica I'd check with a voltmeter to see what is coming in from the panels. Some hard fact finding is key to understanding this. Could be even be a panel overheating and failing. Can you measure the voltage from the panels as well as the output on the mppt to the battery to see what is actually going on maybe?

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Alison Ely avatar image Alison Ely commented ·

Please see my reply above to klim8skeptic.Hopefully I've answered your question.

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ejrossouw avatar image ejrossouw Alison Ely commented ·

I just responded :)

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