Lawrence_craig
New Member
Hi all.
I have just installed my DIY LiFePO4 12v 4S battery. I have full Victron charge kit (and SmartShunt) with a JK BMS.
I just wanted to check the behaviour when the battery is fully charged.
When it is fully charged (via a Multiplus on 230V shore power supply), the JK BMS cuts the charging off due to Cell Voltage Over Voltage Protection (14.4V, 3.6v/cell). The battery then stops charging. It's worth noting I am currently seeing a Cell Voltage Diff of 0.05v when fully charged if that's important. What I then tend to see what happens is the battery will sit full for a few mins, the voltage will then drop to below the OVPR (14/3V, 3.5v/cell) and the Multiplus will then pump power back into the battery (>30a @ 14.2V) for a minute or so. However, in that time the battery charging was cut off, 30amp was definitely not drawn, the other loads should have also been supplied by the shorepower anyway (current load is only 100W). This seems strange to me.
Is this normal behaviour or should I be looking into something? I have a feeling I have the OVP set incorrectly vs my Victron charge settings.
Parameters for info:
JK BMS
OVP: 14.2
OVPR: 14.1
Victron:
Abs: 14.2
Float: 13.5
I have just installed my DIY LiFePO4 12v 4S battery. I have full Victron charge kit (and SmartShunt) with a JK BMS.
I just wanted to check the behaviour when the battery is fully charged.
When it is fully charged (via a Multiplus on 230V shore power supply), the JK BMS cuts the charging off due to Cell Voltage Over Voltage Protection (14.4V, 3.6v/cell). The battery then stops charging. It's worth noting I am currently seeing a Cell Voltage Diff of 0.05v when fully charged if that's important. What I then tend to see what happens is the battery will sit full for a few mins, the voltage will then drop to below the OVPR (14/3V, 3.5v/cell) and the Multiplus will then pump power back into the battery (>30a @ 14.2V) for a minute or so. However, in that time the battery charging was cut off, 30amp was definitely not drawn, the other loads should have also been supplied by the shorepower anyway (current load is only 100W). This seems strange to me.
Is this normal behaviour or should I be looking into something? I have a feeling I have the OVP set incorrectly vs my Victron charge settings.
Parameters for info:
JK BMS
OVP: 14.2
OVPR: 14.1
Victron:
Abs: 14.2
Float: 13.5
Last edited: