I’m having trouble charging a Battleborn LiFePO4 battery with my victron solar charge controller. I have a 160W panel connected to a Bluesolar mppt 75/15 and a 100Ah (more specs below) inside a van.
I’ve had no issues since installation in November 2023 until a month ago when the amps, read from the solar charge controller, slowly diminished to 0.1A (volts consistently between 14-21). A simple OFF/ON reset via the master battery switch in the van fixed the issue for about a month. Last week the amps started dropping again over a 5-day period and the battery dropped below 10V and shut off. The OFF/ON reset did not work the second time.
During this time period the vehicle was not driven or moved, so I don’t suspect any connections getting loose. The panels are clean and in a sunny location. I used a multimeter to check volts and amps at the panel (~21V, 5.5A) and then again at the end of the mc4 extension cables that feed the charge controller and got approximately the same readings of 21V/5.5A. The controller was still reading 0.1A (the photos show 0.0A but the value fluctuated between 0.0 and 0.1).
The battery was recharged using first a standard shore charger with the closest charge profile I could get to the recommended by Battleborn. The battery died again a few days later and I used DC to DC from a car battery to recharge up to ~13V, so I don’t think the battery has gone bad as it is barely 2 years old, still holds a charge and runs the 12V DC loads (lights, small fridge, fans). Nothing with a huge draw. The Battleborn rep I shared the details with had no reason to believe the battery was the source of the issue.
My suspicion is the solar charge controller is faulty — The 20A fuse isn’t broken, but I replaced the fuse just to double check. All wiring connections appear to be in good shape and no breakers enroute are flipped. The firmware has been updated when available, and the charge profile is the suggested LiFePO4 configuration (and did not change during the onset of the issue). I went through the Victron troubleshooting chapters and found no solutions.
Any thoughts or ideas are welcome - thanks in advance, Stephen.
The spec says isc is 9.9A isc. Did you short circuit the panel to check it like that?
Also there is a bit of conflicting information…
Is there a panel or more than one panel?
As a further note though there is barely enough voltage under load to charge 5v above gets the mppt started. So if the panel is weak it will have been struggling for a while.
For clarification there is only one 160W panel. I did short circuit the panel and got ~5.5A. I will check again tomorrow at peak sun. Panel specs say Isc is 9.14A, still this seems far away from 5.5A. Anyway I’d still expect to see 5.5A via the controller bluetooth, but I’m reading 0.1A (battery not fully charged).
I first checked voltage and amps at the panel by disconnecting the mc4 extensions and measuring the readings from the panel and wires that came attached to the panel. Then I reconnected the mc4 extensions and got similar readings at the end of the extensions where the wires connect to the mppt controller port (I disconnected the wires from the controller port to get the readings). So I don’t suspect a wire issue between panel and controller.
Regarding your last note, my understanding is that I’d need 12v+5V to get the mppt going and 12V+1V once it’s started to continue a charge. My reading of 18.30V should have been enough to start the mppt and consistent readings above the 12V+1V threshold should have been enough to provide somewhat of a charge, but I still get 0.1A at the controller even when the draw from the load is as low as -0.20A.
No, it requires 5V above battery voltage to get going, so if you have lithium which may well be at 13.3V at daybreak, you need 18.3V to get the MPPT going, so your panel really is on the cusp of working / not working. If you are northern hemisphere then winter will be reducing panel performance.
I live in Phoenix, AZ and had no issues charging the same loads last winter, but I’m still considering this as a possibility. I’ve added some recent screenshots of the controller readings at 1030am, will check again around 1-2pm.
Today, I again got a reading of ~5A at the terminals before the PV wires enter the solar charge controller but 0.1A from bluetooth. Battery isn’t full. Also the controller flashes all 3 lights 6-7 times every time I try to connect via bluetooth.
The first time the amps began dropping, I reset everything via the master ON/OFF battery switch. That fixed the issue for a month which lead me to believe the source is a computer somewhere inside the mppt…
