My system is 1.5 years old and I was able to reach 14.7V at the absorption stage a few months ago. I unhooked each battery and tested the voltage and found they were all sitting around 13.27V meaning there is no imbalance and this likely isn't an issue of a bad battery. Highest voltage achieved is 13.7V. System details: -Victron Energy MultiPlus 3000 Watt 12 Volt Inverter & 120 Amp Battery Charger -Victron Lynx Distributor -Victron BMV 712 -Victron MPPT 100 | 50 -4 x 100Ah 12V LiFePO4 -500 Watts solar