Battery Voltage vs. State of Charge was (ET) ryobi

["Travis Creswell" <ozsolar ipa net>]

If I may politely add something to this chart that I'm sure most are 
already
aware of.  But in case someone new is reading I wanted to add some 
clarity. 
As Dave mentioned, it's open circuit voltage.  Perhaps a clearer way to say
it would be "resting".  Resting typically means no charging or discharging
for at least 3 hours and is even more accurate if you wait until overnight
to compare your battery's voltage to this chart.

I mention this because I have several off grid solar customers who will 
shut
their systems down if the voltage gets under 12.4 regardless of what loads
are on.  I seriously doubt their batteries have ever been under 85% SOC and
nothing I do will convince them differently.  I've installed an amp hour
meter and they even made sure they knew how to use a hydrometer   They'll
spend the night in the dark before they will let the battery get under 12.4
volts.

Travis Creswell
Joplin, MO

----------

>
>If your 12V battery was measuring 2.2V it is dead beyond death. You can 
>get
>a charge on it but it will only be a surface charge. It will die in matter
>of seconds. It is my understanding that if your battery is below the 0%
>state of charge then it will more than likely be unrecoverable.
>
>If I miss read what you were stating my apologies
>
>Here is a open circuit measurement chart to go by that I found.
>
>SG        Volt         SOC
>1.265    12.66       100%
>1.225    12.45       75%
>1.190    12.24       50%
>1.155    12.06       25%
>1.120    11.89       0%
>
>SG is Specific Gravity
>SOC is State Of Charge