Off Grid Chalange

[Bendesa1962]

Problem:
Off Grid Systeem:
Morningstar SureSine inverter 48 VDC 2500 Watt
Morningstar Tristar TS 45 Charge Controller
Battery bank 4S2P 8 x 12V 200Ah VRLA Gel batteries
4 x Longhi 550-Watt Solar Modules
System load:
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The system is located at Pulau Rote in Indonesia.
After it was installed in March of this year the client did ad a huge fridge/freezer to the system.
Specs of the fridge freezer:

• Fridge/freezer: Samsung RS61R5001M9
• Rated power: 270 W (220 V / 50 Hz)
• Normal running power: approx. 120–150 W
• Compressor startup surge: approx. 1000 / 1500 W (very brief)

The system runed fine for 5 months and then problems occur. During the night the Morningstar inverter does an automatic Low Voltage Disconnect which means the whole system went off. After a while, sometimes 30 minutes but mostly several hours in the night the system recovers but it’s possible that after a while during the night it switches off again due to a low voltage disconnect of the inverter.

When they disconnect the fridge freezer verything is smooth

I tell the client that this extra fridge was not in de design demands and they do understand that but they also ask how it is possible that it did run fine for 5 months. I think it has to do with SoC of the battery bank and the surge power of the fridge freezer. What do you guys think about the situation. And how could it be repaired?
Many thanks for participating
Kind regards

[organic farmer]

How frequently have they been performing an Equalize Charge?

We must assume that the individual batteries are going to be out of sync, we must pay strict attention to holding them in sync before we can expect them to hold a charge through the night.

[Bendesa1962]

Hi organig farmer, thanks for your reply.

I'm confused to be honest because I found this info on the web:

Equalize Charge and VRLA Gel Not recommended: A classical equalize charge (with increased voltage and gas formation) must not be applied to VRLA Gel batteries.

Reason: Gel batteries are sealed and equipped with a valve. They are designed to allow internal oxygen recombination.

During an equalize charge, excessive gas formation occurs → this cannot escape or be mixed as in flooded batteries.

Consequence: Pressure buildup, drying out of the gel, cracking of the separators, and permanent capacity loss.

Manufacturer guidelines: Virtually all manufacturers (e.g., Sonnenschein, Exide, Trojan) explicitly state that equalizing is prohibited for Gel and AGM batteries.

[organic farmer]

I am using Exide Lead-acid batteries and they need a monthly equalize charge.

When they are not equalized the symptoms sound just like the OP.

[SunEagle]

I am using Exide Lead-acid batteries and they need a monthly equalize charge.

When they are not equalized the symptoms sound just like the OP.

I agree. I also am not sure how those 8 batteries are wired. If they are in parallel at all then some are not getting an equal charge