How to Set LiFePO4 Battery Charging Voltages on a Boat

Equipment and information required

• Your pack's datasheet
• Access to every charging source's settings

How to Set LiFePO4 Battery Charging Voltages on a Boat: steps

1. 01

   Get the figures from the pack, not the internet

   Cell configurations and BMS cut-offs differ between brands. The datasheet for your pack is the authority, and a generic LiFePO4 preset is a starting point at best.

2. 02

   Set absorption voltage and time

   Absorption fills the last part of the bank. Too high stresses the cells and can trip the BMS on high-voltage cut-off; too low leaves the bank permanently short of full and the monitor unable to synchronise.

3. 03

   Turn float off, or set it to a storage voltage

   LiFePO4 does not need a float stage, and holding it near full is where it ages fastest. If the charger insists on a float value, set it to the storage figure the manufacturer gives.

4. 04

   Disable equalisation everywhere

   Equalisation is a flooded lead-acid maintenance cycle. On a lithium bank it can drive voltage past the pack's limit. Check for it on solar controllers especially, where it is often on by default.

5. 05

   Set the same figures on every source

   Mains charger, solar controller and DC-DC charger. Sources fighting each other at different voltages is a common cause of a bank that behaves differently depending on how it was charged.

6. 06

   Set the low-temperature cut-off

   Charging LiFePO4 below freezing damages it permanently. If your BMS or charger supports a low-temperature charge cut-off, enable it rather than relying on remembering.

7. 07

   Verify against the monitor

   Run a full charge and confirm current tapers to the tail figure and the monitor synchronises. That is the proof the settings are right on this boat.

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