Victron Lithium Batteries, no cell rebalancing

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martinhh1 asked Oct 19, '22

Victron Lithium Batteries, no cell rebalancing

Our boat, built 2017, has 2 Victron battery boxes, each with 4x90Ah Lifepo4 batteries installed (in total 8x90Ah batteries). Color Control shows 166 total charge cycles. The system worked fine for 5 years. The batteries predate the Smart batteries - meaning no Bluetooth connection.

All batteries in one box deteriorated in the past weeks or months and two batteries failed entirely with low voltage and don’t take a charge anymore. One battery seems okay but triggers a high voltage alarm. All the problematic batteries are in one box. The other box works fine.

What could be the reason?

Lithium Battery

2 |3000

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Answer 1 · 2022-10-20T05:05:39Z

Paul B answered · Oct 20, 2022 at 05:05 AM

Very hard to give a firm reason

more than likely the batteries have been 100% flattened. at some point . if this has happened then it badly damages the batteries and they will fail very quickly

Its important that a external BMS relays are installed so that the battery is turned off before they are fully flat.

ie any cell goes under 2v then the battery is usually badly damaged.

this is just a guess as to the likely cause

2

2 |3000

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martinhh1 commented · Oct 20, 2022 at 01:42 PM

5 years ago, during installation, the installer in France let it happen that the batteries went down to 9.11V, which are 2.27 Volts average per cell. Wondering if this could be the cause 5 years later?

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Stefanie (Victron Energy Staff) ♦♦ martinhh1 commented · Oct 20, 2022 at 03:51 PM

Absolutely. If the voltage of a LiFePo4 cell falls below 2.5V, permanent damage can be assumed, although they can often be brought back to life. But with very reduced performance and significantly less capacity and service life.

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