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markaos asked

Bluetooth app showing more than one 100 20 MPPT

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Im having multiple problems with this installation.

330w monocrystaline panel

100/20 mppt

12/250 inverter

2x Bluetooth dongles

3x 12v 110ah carbon gel batteries.

To power 39w diaphragm air pump & 45w pond pump.


Bluetooth is showing 2 MPPT's There's only one in installation with a 12/250 inverter.

PV Voltage reads 12.39 at terminals but reads 36v when disconnected from mppt & directly to multimeter.

Batteries read 12.57 from MPPT battery terminal.


I understand batteries won't charge unless pv Voltage is more than batteries but I can't understand the drop once connected to MPPT.


Please help


Thanks in advance.


MPPT Controllers
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9 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

You connected a Bluetooth dongle to a Smart MPPT that already have a Bluetooth module build-in. Because of that you see it twice.

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markaos avatar image markaos commented ·
Im sure there are 100/20 with built in Bluetooth & 100/20 that require a dongle.

I will measure tomorrow in full sun.

The cable run from panel to MPPT Is exactly 5 meters.

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markaos avatar image markaos markaos commented ·
I didn't get there in time for full sun but to my surprise the system was working with only the diaphragm air pump connected.
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markaos avatar image markaos commented ·

I've now obtained inverting remote cable to go between MPPT & 12/250 Inverter with inverter powered directly from batteries. I need to come back tonight to double check the remote cable functions and switches inverter off at 12.62v. Fist time in float for a while.screenshot-20220719-152625.jpgImage Caption

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markaos avatar image
markaos answered ·

Hello Kev.

I am worrying that the panel I bought is not as good quality as I thought. ja solar jam60s17-325/mr.

Ive got three of these batteries;

https://www.ebay.co.uk/itm/175340322753?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=u8yf6H81TPi&sssrc=2349624&ssuid=vB-17T8HRuS&widget_ver=artemis&media=COP


In answer to your question, It no longer showed two MPPT'S in the device list.



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kevgermany avatar image kevgermany ♦♦ commented ·
Solar output is very variable, depending on weather. I see your peak power hit 274W, not that bad. This will not only depend on the amount of light, but also the load and ability of the batteries to take charge. Battery voltage isn't getting to where it should be, this will lead to damage and short battery life. It would be worth doing some digging to find out why.

Assuming you run the two pumps all day, total power used is about 2kWh. You're generating nowhere near that on the good days.


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Mike Dorsett avatar image
Mike Dorsett answered ·

For the PV voltage, disconnect the module from the MPPT controller. You have measured the open circuit voltage at 36V, now short the two wires from the module together (DO NOT DO this with it connected to the MPPT) and measure the short circuit current. If this is low, then you have a high resistance point in your PV wiring which needs correcting. Once you have done this, you should have charging - be sure to edit the MPPT settings for the battery voltages.

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markaos avatar image
markaos answered ·

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markaos answered ·

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markaos answered ·

Im based in Southend on sea which is South east England.

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kevgermany avatar image
kevgermany answered ·

Looking at your numbers, the diaphragm pump on its own is pulling more than the panel is generating.

You might be undersized on panels, unless you're expecting the multiplus to supplement.

Did you check the double Bluetooth as suggested by @Matthias Lange - DE , Smart Solar MPPT has the built in Bluetooth, Blue Solar does not.

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markaos avatar image
markaos answered ·

Yes you're totally right It was an oversight of mine, I need another panel.

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markaos avatar image
markaos answered ·

Thank you for your comments. I visited again last night at 0100 in the morning and diaphragm pump was still running so batteries are charging but all that time is in BULK.(see attachment)Screenshot_20220717-002429.jpgscreenshot-20220717-002238.jpg

Couple more questions;

Has anyone any success in supplementing PV power using a wind turbine & 2nd MPPT.

& will a BMS or other device boost the effectiveness of charging.

I ask because Im limited to space for additional solar panels - I have a telegraph pole mounted vertically with a unistrut top collar and gate pin hinges down to solar panel unistrut frame that kicks out from telegraph pole with two unistrut braces of 1500mm to give panel 45⁰ angle.


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