Rogue MPPT, 490W and charging mysteries
Now that we were finally all in one place - me, Rogue 3048 and my rig - it was time to have some fun. 1)Battery: old starter, tested beyond dead, plates above the water. No wonder, 8 months in Mex...
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Almot wrote:
3) Testing AGM 100 AH. Like I said, it spend more than 8 hours in Abs. Next day battery Voc=13.05. Surprise #3: V on load = 12.45. This is 83%. What the heck? It was 75% before 2 days of charging. Alright, let the real SOC test commence. V load dropped from 12.45 to 12.0 (=50% SOC under load) after 4.75 hours. This is 38 AH. So it was 76% full after it has been charged to 1.5A min.
So, it was 75% SOC before charging, 83% right after many-many hours of Absorption on 490w system, and load test revealed that it was not even 83%, but ~76%.
Also, the battery needs to have been resting for several hours at least (a day is best) before its voltage will give you anywhere near an accurate SOC estimation (hard to do with voltage anyway). In other words, load the battery, then let it rest for a suitable length of time, and measure its voltage again.
