Very expensive batteries
Very expensive batteries, degraded cells and no real warranty solution
I purchased two Meritsun LFP200-48 10kWh batteries for more than PHP 340,000.
After only a few years, both batteries developed serious cell imbalance problems.
I spent a huge amount of time troubleshooting these batteries, providing BMS logs, historical measurements and technical data to Meritsun.
Eventually, Meritsun’s own technical analysis stated:
“Severe cell imbalance / capacity degradation in specific cells”
and:
“This indicates a weak/degraded cell.”
I followed their instructions and even updated both BMS units from firmware 2.03 to the 2.09 firmware supplied directly by Meritsun.
The degraded-cell problem remains.
I then asked Meritsun to provide the necessary replacement cells under warranty.
Their solution?
Pay $30 for each replacement cell.
I even offered to find and pay for a qualified technician myself in the Philippines. I only asked Meritsun to supply the defective replacement cells under the warranty.
After paying more than PHP 340,000 for batteries sold as long-life products using Grade A cells, this is absolutely not the level of after-sales support I expected.
My biggest warning to potential buyers is therefore simple:
Before buying a Meritsun battery, do not only ask about capacity, Grade A cells, cycle life or warranty duration. Ask exactly what happens when a cell actually becomes defective.
Ask who will repair the battery in your country.
Ask who pays for defective replacement cells.
Ask whether there is an authorized technician.
Ask what happens if your original reseller disappears.
A long warranty sounds excellent when buying a battery. What matters is what happens when you actually need to use it.
I have kept the purchase documents, BMS logs, thousands of historical measurements and my conversations with Meritsun, including their own technical diagnosis.
This review describes my personal documented experience with two Meritsun batteries.
At this stage, based on my experience, I would not buy Meritsun batteries again and I cannot recommend them.
If Meritsun eventually provides a proper warranty solution, I will update this review and report that fairly.
Until then, potential customers should understand the after-sales experience I have had before spending this kind of money.