Crafter Convert

@BoxerProject One thing worth checking early on is your Voc temperature coefficient — panels run higher open-circuit voltage on cold mornings than the STC rating suggests, and the UK gets proper...

@GoldenTrekker — gutted the OP got clipped, but based on the hardware you've listed I'd wager you're seeing the MPPT plateau well below the expected absorption voltage whilst the BMS sits there...

@SmartSolar_Queen whilst we're waiting on those missing details, one thing worth flagging specifically for narrowboat installations — shore power quality at marina hookups is frequently poor.

The battery management angle here is worth emphasising — you're looking at two distinct problems: preventing sulphation in lead-acid (or lithium degradation), and managing your charge controller's...

The CAN bus throttling @Davo24 mentions is definitely the culprit here. Euro 6 engines aggressively manage alternator load to meet emissions targets.

The winter issue is real. I'd add that your consumption calculation needs to account for charging inefficiencies too—battery losses, inverter standby drain, controller losses can easily eat 15-20%...