I have a 2018 Flying Cloud with a WFCO 9855 converter. According to their website, it uses 13.2 V float, 13.6 V absorption, and 14.4 V bulk charging voltages. I just replaced the dealer killed SRM-24 batteries with some 6 V golf carts from Costco as a temporary fix on my way to lithium. I also added a Victron BMV-712.
Weíre now at our first campsite going on the new batteries. Over the course of around 24 hours we used 96 Ah of our 210 Ah total. The BMV seemed to track all that fine. At that point we hooked up our 2000 W generator to the shore power connection to charge. Unfortunately the converter doesnít seem to go into bulk and only around 10 A /120 W ever flows into the batteries. I donít remember the exact voltage. It was thirteen point something. Anything going on in the trailer reduces that 10 A. After about 5 hours, around 50 Ah had gone back into the batteries, but suddenly the BMV said 100%.
So all that gets me to the question on the BMV settings. It uses the charged voltage (default is 13.2), tail current (default 4%), and charged detection time (default 3 minutes) to decide when the batteries are full. 4% of my 210 Ah batteries is 8.4 A for the tail current it is using. I can see how we could have easily been down to that while making dinner since every 12 V thing you use was reducing the batteryís share of the ~10 A the converter was producing. Should I set tail current lower? If 8 A is flowing into the battery, that doesnít seem very full.
Victron says to set the charged voltage 0.3 V below the float voltage, which would be 12.9 V. I donít quite get how a value below the float voltage is ever going to happen as long as the converter is on though. On another thread on here someone else said to set it above float not below. What are other people using for this number? Are my settings fine and the converter is the problem, do my BMV values just need adjusting, or what is going on?
Any thoughts are appreciated.