New dual 6v's. Need some advice plz
So I just picked up two Interstate GC2 6v's from Costco for $94 ea. The sticker states 210Ah@ 20hrs. I dont plan on using them for about another month so I will just store them inside so they dont f...
Forum Discussion
pianotuna wrote:
You need to know what the battery maker says is the fully charged resting voltage. And that number is *only* correct at 25C (77 f).
As someone else said--a hydrometer is a far better way to measure state of charge.
If we assume that 12.72 is fully charged, then 12.65 is 99.4% of full. Unfortunately that last 0.6% means that the jar may well sulphate.
I'm not sure I'd say 12.65 is 0.6% from full. discharged a flood cell battery is around 11V, not 0.00V so dead to full charge is about 1.7V, and 0.07V is about 5%. so 12.65 V is around 95% SOC. the graph from 10% SOC to near 100% SOC is pretty linear with battery voltage.
and as you correctly point out just because fully charged voltage is XX.X 12.8 or whatever does NOT mean that charging a battery with a 12.8V charger will fully charge it. It Won't and will eventually lead to sulfation. Flooded cell batteries need a period of time with a voltage around 14.6V to fully charge and avoid sulfation. They need to stay at that 14.6ish volts until the charge current drops below a certain % of battery AH capacity. then they can drop down to a float voltage.
