The cells of all 4 batteries that I bought are within 5mv of each other across all 16 cells (they came from the same truck) and only have 25 discharges on them.
So if I do setup for CC/CV. I have a huge range of settings and am not sure the right ones. The manual for interface/monitor is linked above but I've copied the relevant sections here with my comments/questions in
RED
This is in an RV motorhome, I do NOT have solar and I am mostly plugged into 110V. I will occasionally be off-grid while driving from A to B and some boondocking. I have a 10KW Generator for boondocking to charge the batteries and enable AC. I do have some concerns about the 12V DC load emptying my batteries to a harmful level so I am considering buying the MIUSA-BMSLV if that will allow for balancing and low voltage cutoff.
Set Battery Type (CC/CV) – The CC/CV selection provides a Constant Current/Constant Voltage (CC/CV) charging method with an adjustable charge voltage and a setting that limits output current—if needed. It consolidates all the battery charge settings that are required for a 2-stage charging cycle (i.e., Constant Current and Constant Voltage). Note: CC/CV settings only display if CC/CV has been selected from the 03 Battery Type menu. Info: If CC/CV has been selected from the 03C Battery Type menu, the following menus are no longer accessible and display “CC/CV Controlled” when selected: 01D Max Charge Amps, 03D Absorb Done, 03F Max Charge Time, 03G Final Charge Stage, 03H EQ Reminder Days. This is to prevent charging conflicts that could occur while in the CC/CV profile.
CAUTION: Whenever the CC/CV battery type is selected, some settings—within the menus that are no longer accessible—are internally linked to the CC/CV settings and can be automatically changed. Because settings can be automatically changed once CC/CV has been selected, if a different battery type is selected all charge settings must be reviewed to ensure they are correct for the new battery type selection.
Set Max Charge Amps – Sets the maximum charge amperage allowed to charge the batteries during the CC/CV charge cycles. The range of settings are provided to limit the charge current to the battery bank, which helps prevent battery overheating caused by charging at too high a charge rate.
Default: 200 ADC
Range: 20 - 990 ADC
Is this the total amps of the battery bank? Or is it the maximum amps applied during the CC phase? It looks from the chart below that it is the max amps during the CC phase.
Set CV Charge Volts – Sets the voltage level at which the charger will hold the batteries during the Constant Voltage cycle.
Default: 13.8 VDC (12v), 27.6 VDC (24v), 55.2 VDC (48v)
Range: OFF, 12.0-16.0 VDC (12v), 24.0-32.0 VDC (24v), 48.0-64.0 VDC (48v)
Info: If the BMK (Battery Monitor Kit) is connected, the DC amps value determined by the BMK (under METER: 05D DC Amps-BMK) will be used by the CC/CV’s Max Charge Amps setting instead of the inverter’s DC calculated current (shown under METER: 01B DC Amps)—as it is more accurate (+/- .1 ADC).
I could set this as high as 14.6V which is what the battery says its maximum input voltage is according to the battery front. Here is where I'm concerned about making a mistake. Suggestions are much appreciated. I did buy the BMK, but have not installed it yet. I think this will be an ideal solution, however I would like to understand and implement this system without the BMK.
Figure 3-10, CV Charge Done Time/Amps Stages (INV/CHG)
Set CV Charge Done – These selections determine when the second stage of charging (Constant Voltage) is finished. If using the CV Chg Done Time or CV Chg Done Amps selections, once the Constant Voltage charge cycle is finished, it transitions to a Silent charge stage. After entering the Silent charge mode, the charger automatically stops charging, but is still actively monitoring the battery voltage. The charger will remain “Silent” until the battery voltage drops to the Set Recharge Volts setting, at which time the charger will start another Constant Current/Constant Voltage charge cycle (see Figure 3-10).
Default: CV Charge Done Time
Range: Time, Amps, Hold CV Chg VDC
This setting is confusing, wouldn't there be a better trigger than time or amount? I don't understand how this works, but intuitively to me, it seems like during the CV phase that the voltage would drop to a point where you would know its full. There is also an option for HOLD CV CHG VDC where a constant voltage is held on the battery at all times that I have 110V (plugged in or running the generator). I dont have solar YET. This specific setting is not copied into here. If discharging the battery to a certain threshold is ideal rather than keeping it topped off then that is probably not an ideal setting.
Set CV Chg Done Time – The CV Chg Done Time selection is used when a specific time is selected to be the best solution for determining when the batteries are fully charged and the Constant Voltage stage needs to end. This setting determines how long the charger will hold the battery voltage at the CV Charge Volts setting—based on a set time period. When using time, the battery bank size will typically determine the length of the CV Chg Done Time setting. The larger the battery bank, the longer the time needed to ensure a full charge to the batteries. If the setting is from 0.1 to 25.5 hrs, the charger transitions to the Silent charge mode after the battery voltage has been at the charge voltage setting for the selected time. Refer to Table 3-2 to assist you in selecting the CV Chg Done Time setting based on the AHr capacity of your battery bank. Note: After choosing Set CV Chg Done Time, the Set Max CC/CV Time and Set Recharge Volts settings must be determined (see next page).
Default: 2.0 Hrs
Range: 0.1-25.5 Hrs
Set CV Chg Done Amps – The CV Chg Done Amps setting is used when the DC amperage supplied to the batteries (also known as “return amps”) determines when the batteries are fully charged and the Constant Voltage stage needs to end. This setting determines how long the charger will hold the battery voltage at the CV Charge Volts setting—based on a minimum current setting (i.e., return amps). During the Constant Voltage charge mode, as the battery charges, the current from the charger slowly decreases. When this current decreases below the CV Chg Done Amps setting, the charger transitions to the Silent charge stage. Most battery manufacturers use a specific formula to determine the return amps that indicate a full charge for their particular type of battery. The formula used by most manufacturers to absorb the batteries is C/20, where C=Battery Bank’s Total Amp Hours. Basically, they take approximately 5% of the total battery bank size and consider the battery totally charged when the charger’s return amps drops to this level.
Seems less than ideal, but maybe better than the TIME method? I have NO clue though, so help is greatly appreciated.