[MAWilsonPE]

I installed two SmartShunts, one near the front pair of batteries and one near the new rear pair of batteries in order to measure the amps flowing from each pair during a discharge and charge cycle. I am shocked at how much the front pair draws and charges first leaving the rear pair way behind in the cycle. As many as 3x the amps flowed from (or to) the front pair vs. the rear.

For my first test I ran one A/C unit for 3 hours until the front pair of batteries discharged to 50% taking readings every 10 minutes. The rear pair discharged only to a level of 80%. I had the solar turned off so the test would be as simple as possible.

I then plugged in to shore power, still with the solar off and charged the batteries at a rate of about 120 amps (DC). Again, the front pair took most of the charge although both sets reached 95-97% pretty much at the same time. Once the front pair hit 97% the amps went preferentially to the rear. Once the system went into absorb charging, the flow was about the same to both. This is because absorb charging is done at only a few amps and the losses to the back are minimal. See the numbers below.

In summary, a worthwhile test. I cannot tolerate any more weight in the front of my unit so I am now in the process of moving the front pair of batteries to the rear where I will close couple them with the new pair. I will run another set of 4/0 cables to the front to minimize the losses. Not an ideal set up due the long run between the batteries and the inverter but this will eliminate this imbalance issue and give me full use of the amp-hr capacity of all four batteries.

Best Regards, Mike