We had it out camping four nights last week and I noted that by mid afternoon each day (~2PM) the controller was in float mode but the battery was less than full charge (93% end of the first day, 87%, then 84% by the third day. The values displayed by the Victron Connect app seemed to indicate normal charging.
Using the LiFePO battery preset on the controller.
My belief is that at 2pm on a sunny afternoon, the controller should still be charging the battery if the battery is at less than 100% ??
Any ideas what’s going on here?
Does the controller need a smartshunt/battery monitor to determine the battery charge level?
How far away is the charge controller from the battery and what gauge cable? The controller doesn’t know what the voltage is at the battery only what it reads at its own terminals. If there is significant voltage drop it could be going into float too early like you are describing. Are you using the bluetooth connection to the smart battery to get the state of charge? The voltage at the battery may be very different than that at the MPPT terminals. If you are using your factory wiring this scenario is highly likely.
If this is the case you have a few options. Upgrade the cable size and/or get the controller as close to the battery as possible or install a Victron Smart Battery Sense on the battery and set up a Victron Smart Network in the MPPT then connect the Smart Battery Sense to the network. It will then share the actual battery voltage with the MPPT.
I personally would take out the controller, butt connect the wires together and relocate the controller as close to the battery as possible.
I trust that the controller is consistent when going into float. i.e. it’s charging to the default 14.2 V for LFP before going to float.
How are you reading SoC from the battery? Is there an app which uses Bluetooth? Can you see/change the BMS settings? Usually there are settings which tell it when to reset the SoC to 100%, which needs to happen on a regular basis to have a reasonably accurate SoC. It sounds like that’s not happening, so the battery’s SoC is getting out of sync with reality.
The battery is an Eco-Worthy and it has built-in bluetooth and an app that displays state of charge, voltage and current. There doesn’t seem to be any changeable settings for the BMS. I also bought a smart charger which brings the battery to 100% (as reported by the bluetooth app)
As for the location of the controller, indeed, I merely replaced the factory controller in the same location, which is in the kitchen. Wires to and from are 10awg but still probably a good distance from the battery. I think the idea to re-locate the controller closer to the battery has merit.
What I really need to do is put a meter on the controller output and the battery terminals to see what is happening and make some notes. Will do that next time I have the trailer out.
I would definitely get the controller close to the battery. There’s no telling how many twists and turns that cable takes. It’s best practice to have the controller as close to the battery as possible regardless of the problems you are experiencing.