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123dyonisos asked

Smart Solar MPPT 150/85 MC4 charging 12V, 24V, 36V but not 48V

Hi everyone!

I've got a 16S 48V LiFePo4 system with a Smart Solar MPPT 150/85 MC4. ~80V OCV with 4 ~300W panels.

Been having issues with the MPPT charging intermittently. I switched BMS a few times thinking that was the issue.

Now the MPPT is not charging more than 0-10W/0-0.1A while in Bulk. I've connected the MPPT directly to the battery pack (without BMS) for troubleshooting to eliminate any other issues.

The MPPT charges perfectly when:

- connected to another 12V battery

- connected to any 4 connected cells of the 16S LiFePo4 assembly (set to 12V)

- connected to any 8 connected cells of the 16S LiFePo4 assembly (set to 24V)

(only charging for very short time and same time to avoid imbalance ofc)


As soon as I connect it to all cells at 48V it stops working.


I've checked battery continuity, individual cell voltages, cell connector bars. PV strip continuty is perfect, been charging a Bluetti unit at 750W without issues.

I've scoured this forum and tried everything remotely applicable.

The MPPT is configured with standard LiFePo4 settings. Charger is on, jumper connected and ofc it charges at <48V.


Is it possible that only the MPPT 48V charging circuit broke? Am I missing something?

Thanks!

MPPT Controllerssmart solar charging behaviour48v battery
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klim8skeptic avatar image klim8skeptic ♦ commented ·
What is the model # and serial # ??
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123dyonisos avatar image 123dyonisos klim8skeptic ♦ commented ·

PN: SCC115085512

SN: HQ20297DPDP

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klim8skeptic avatar image klim8skeptic ♦ commented ·

SCC115085512 - SmartSolar MPPT 150/85-MC4 VE.Can (12/24)

This is a 12/24 volt (battery) model mppt. Not suitable for 48v battery systems.

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123dyonisos avatar image 123dyonisos klim8skeptic ♦ commented ·

The data sheet says 48V is fine.

1665582494926.png


I can set it to 48V and have charged at 48V before, it was just never reliable.

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1665582494926.png (4.2 KiB)
1 Answer
klim8skeptic avatar image
klim8skeptic answered ·

12 / 24 volt mppt's


SCC115085512 - SmartSolar MPPT 150/85-MC4 VE.Can (12/24)

This is a 12/24 volt (battery) model mppt. Not suitable for 48v battery systems.

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123dyonisos avatar image 123dyonisos commented ·
Thanks! That is indeed very difficult to figure out.
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Related Resources

MPPT Product Page

MPPT Error codes

MPPT 150/60 up to 250/70 Manual

Additional resources still need to be added for this topic