I’m re-installing my 5th-wheel solar components after a catastrophic failure, frying nearly every electronic device in my 5th wheel. I can’t figure out what would have caused it. One of my two MPPT controllers died, along with all my slide-out controllers, leveling-jacks, fridge, access point, thermostat, LEDs, and lord knows what else I will find as I rebuild. It did manage to blow all the fuses that had a device connected. My 2 EG4-LL batteries appear to be fine.
I’m afraid to connect my 12v RV panel to the system, thinking this could happen again. Should I connect a DC/DC power supply between the systems or go all out and add another completely isolated battery?
The only think I can think of is a violent surge caused by my MPPT controller failure or the battery BMS shutting off while charging. Victron support hasn’t returned my email so I thought I would reach out here. The reason I stayed with 12v was to power these sensitive devices. It’s cost me thousands and I don’t want to get bit again.
That is possible. Especially if the voltage is set to more than 3.43 V per cell and 250 V MPPs are used. And if there is no inverter with its capacitors to dampen the voltage spikes.
Inverter was powered off and survived. I have Victron everything except my 12v batteries. Everything is fused but that only protected against amps and didn’t blow except at the RV distribution panel once the electronics failed. Burned out all my slide motors and fried harnesses so the controller must have failed open also.
It was connected. I was able to use the remote switch to turn it on while on battery only. I bought a new Multi-Plus II to replace the Triplite RV3012OEM anyhow but it did seem to test OK. I didn’t try to put a load on it. Other components like the Victron smart shunt which I haven’t tested yet come to think of it. I had dual MPPT 100/50 with 6x100w panels on each one.
Yes, if the batteries are connected to the Cerbo via the CAN bus, they can control the charging process (provided that the charger is connected to the Victron system or can be controlled by it). The Victron devices should also all be connected to the Cerbo and operate as part of the network.
This prevents overcharging and therefore an emergency shutdown, which could otherwise cause an overvoltage (the battery is disconnected by the BMS, causing the sources to run unloaded, which can make their output voltage rise until they are switched off), as the solar controllers in particular may, when switched off, output up to the module voltage Uoc at their output. Naturally, the shutdown process takes a short amount of time (due to software and hardware latency).
When fully charged, the battery will be able to reduce the charging current in good time via the BMS, thereby slowly approaching the upper limit while simultaneously balancing the cells via the balancers. By the way, this is another possible reason why your battery disconnected:
Cell debalancing due to asymmetry between the cells (OVP, UVP) and immediate emergency shutdown ergo
