question

This is realy most unfortunate. The Victron battery warranty is for two years, but I am sure the installer will have your best interest at heart and do their best to ascertain as to why this has happened. I personally will always do problem solving first as if it is a problem with the system, you may just end up in the same situation regardless of the batteries used. Many things jump to mind such as were the batteries regularly balanced? How were the batteries charged meaning via inverter or MPPT? Were there any warning signs such are longer charging times etc before it went wrong? What is the settings used? To many to list, but I sincerely hope you find the answer.

@AndyWilliams

It is not fun when a system lets you down on expectations. Sorry to hear that.

A few more details on the system would be needed here. Is it off grid or ESS? Were you cycling them or keeping them in float service? Which batteries did you actually have? Gel, agm or Vlra? What temperatures have they been installed in?

From what I understand the victron batteries lifespan is measured by their float service. I could be corrected don this, as I have never seen one or used one.

https://www.victronenergy.com/upload/documents/Datasheet-GEL-and-AGM-Batteries-EN.pdf

To be dead honest, I do not like any lead based batteries for the very reason you are experiencing and never recommend them to users, not when there are so many better alternatives on the market these days.

The other thing is were there battery balancers in the system, you always get unbalanced charges in a 48v bank built from 4 12v batteries - Usually the cause of a death in the bank, followed by total collapse.

Has the system been charged according to specifications? Not been allowed to remain in a discharged state? If they were being discharged how far down were they discharged?

I would return all the batteries for them to dispose or diagnose or whatever, not hold my breath, and look for a decent 48V lithium battery bank for the system. Did that on our Victron system and never looked back.

Hi, I had such kind of issue with Rolls Battery, and we tracked down the problem, which was doble. Wrong charging settings on the mppt not allowing the battery bank to fully recharge, and not enough power available during the afternoon in order to perform a full absorption / float cycle. The bulk was fine. I had to add 2 rows of solar panels, with another orientation, and it was fixed. Of course, the batteries were severely impacted but I can still use them for a 10A consumption during 12-14h.

I'll suggest doing some maths with your system, and check if the batteries are really getting the "float" condition.

Michel