tl;dr: Would a ‘non-isolated’ Victron DC/DC charger along with a lead-acid starter battery protect my lithium iron phosphate battery BMS from voltage spikes from my RV’s generator? My lithium battery has been shutting itself off randomly and reading 0 volts, and I think it’s because the generator voltage may be spiking higher than the lithium iron phosphate battery BMS’s voltage limit
Hi!
I’m trying to decide between an ‘isolated’ or ‘non-isolated’ DC/DC charger for my RV setup. I’m considering the Victron Energy Orion-Tr Smart DC to DC Charger (Bluetooth) - 12/12-Volt 30 amp 360-Watt - Battery Charger for Dual Battery Systems - Non-Isolated (or Isolated).
I recently purchased a ECO-WORTHY 12V 280Ah battery for my RV. I’m having a problem where my battery shuts itself off and reads 0V once every 24 to 72 hours. I think it’s possibly because the generator is spiking its voltage too high for the battery, but I’m not sure, because every time it shuts off, my battery monitor also shuts off. Maybe the BMS of the battery is detecting too high voltage and protecting itself? That’s my theory right now.
The battery compartment has 4 red leads (including one red lead for a Victron battery monitor), and 1 black lead to my battery (only 1 large gauge red lead and 1 large gauge black lead). The battery is used to start the generator for the RV, and also runs the DC systems in the RV. I think that the fact there is only 1 black lead, means that everything is being grounded to the RV chassis, right?
I asked the battery manufacturer about the battery/BMS shutting off, and they suggested that I buy their DC/DC charger, and use a lead acid battery as the ‘starter’ battery, and my lithium iron battery to run the DC systems in the RV. I think that would be wired like: Big red lead and big black lead connected to the starter battery. DC/DC charger connected to starter battery and lithium iron phosphate battery. Negative terminal of lithium battery connected to chassis, as well as the ‘black’ terminal(s) of the DC/DC charger connected to the chassis. All remaining small red leads to go to the lithium battery.
As far as I can tell, since my RV uses the chassis as a common ground, that means I should use a non-isolated DC/DC charger, right? But if I use a non-isolated DC/DC charger, will it still do its job of protecting the lithium battery from voltage spikes from my RV’s generator?