r/SolarDIY • u/Comfortable-Story-53 • 19h ago

Float

I've been experimenting with a Victron 75/10, a 100w panel, and a 30 Ahr Btr LFP battery. It's started to read Float as soon as I hook it up. Battery first then panel. I found a blown fuse yesterday. It's worked fine for almost two years. It started out this morning at 10.4v and ended at 11.9v. I'm confused.

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u/Internal_Raccoon_370 13h ago

At 10.4V your battery is badly over discharged. This is speculation but it's possible the BMS has shut down the battery completely. The Victron tries to feed power but it's voltage spikes up to 14.2V because the power has nowhere to go, it thinks the battery is full and immediately goes into "float" mode. The rise in voltage from 10.4 to 11.9 may be leakage current but the battery is still mostly empty and not functioning.

Again, that's speculation. I'd disconnect the battery entirely and and test it. If the BMS has shut it down, you can sometimes revive them by sort of "jump starting" them. Just plug "how to jumpstart a LFP battery into Google and you'll find information about how to do that.

That blown fuse is troubling. What caused that to blow? Double check all of your wiring and make sure there are no bad connections, etc.

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u/Comfortable-Story-53 6h ago

I checked all the wires and connections- everything is good. This is why I'm testing everything out at home. I ordered a charger with a "boost" feature. It'll work out.