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I have 4, 6v deep cycle, 200 ah batteries in series/parallel. Since they are 6v each, I realize that I have a total of 400 ah collectively. That means that I have 200 usable ah before needing to recharge.
When configuring the Vicktron 712 Battery Monitor, would I use the 400ah setting?
I am just making sure that I should not be using 800ah as my setting since they are 6v batteries connected in Series.
Thanks!
It’s the Capacity spec @ 20h you want to input when setting up the 712 and not Reserve Capacity, so make sure the 200ah is the Capacity spec and not the Reserve Capacity Spec.
Capacities/Amps remain the same when wired in series with Voltage doubling, and the opposite when wired parallel, so then you have 2x6V@200 series=200 @ 12V plus another 2x6V@200 in series=200 @ 12V. The two banks in parallel then combine for a total of 400 @ 12V.
The advice in the 1st line is incorrect.
Reserve capacity is a time rating, indicating how long a battery can power a constant 25A load for. A load of 25A is used for this test/metric, regardless of the battery size, which may be quite high for smaller batteries. The reserve capacity time rating is not entered into a BMV.
With regards to the BMV, you need to enter the batteries energy capacity at the constant 20h discharge rate. The constant discharge current (over the 20 hours) will vary depending on the particular battery capacity. The battery capacity is calculated from the constant current x 20h to provide the total battery capacity rating (in Ah). This is the most common metric provided with batteries designed for cyclic use.
If you have 4x 6v 200Ah batteries wired in series/parallel configuration, the final battery bank will be 12v 400Ah. The BMV simply treats the battery bank as one large single battery.
Accordingly you should enter 400Ah into the BMV setup, regardless of the fact that you will not discharge the batteries to below 50% SOC.
You can then set the 'discharge floor' on the BMV to 50% and the 'time to go' calculation will consider this discharge level in that calculation.
