Need Better SOC Chart

pabloesguapo

I replaced the battery bank yesterday.  It was sooooo time. I bought 16 batteries from Costco, Interstate GC2, 6v, 210Ah @20h.  It's a 48v system, so 2 strings of 8 batts, 410Ah.  Budget was a HUGE issue.  Price, out the door: $1570.83.

I can't find decent SOC info on this make/model.  Interstate Customer service is no help.  I found the attached chart online, which gives charging parameters, and way too basic for my taste, SOC for GC2-XHD, - HD and - RD, but not the straight GC2.

I'm wondering if the charge parameters and SOC are the same, or at least similar for the GC2. Is there a chart like this for the GC2 somewhere? 

I'd like to have more detailed SOC information than the published 100%, 75%, 50%.  I'd like to see 10%, or even 5% increments.  Is there a way to extrapolate?  (Is the equation linear or logarithmic?) 

mike95490

No chart attached !
 Voltage is all I have.   But Specific Gravity is the gold standard test. (at a specific temperature)

BB.

Here is a nice article that talks about how a generic lead acid battery state of charge vs voltage vs current charge looks:

http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf

-Bill

pabloesguapo

Sorry.  Here's the chart I found

wellbuilt

I use mikes chart it is very close to my findings .
  The charge voltages are way to high in your chart for absorb and float im not sure about the EQ but it seams to high all so. 

  I use sams club battery’s made by penn  , my absorb is set for 59 v with 3 hours of  absorb . 

  Float 54 v eq 61.5 
 my battery’s like to be charged , they use a gallon of water every 2/3 months  at night after charging they sit @ 75o in the am they are back down to 70o 

pabloesguapo

Thanks.  Those numbers look more normal to me.  I figured what I had was a little high. 

mike_s

FYI, Interstate doesn't manufacture batteries. They relabel/distribute them. The Interstate GC2s they had at my local Costco last year looked like they were made by JCI. The case matched a Varta 300 208 000. That probably doesn't help, because JCI isn't good at publishing tech info, either.

Johann

mike95490 said:

No chart attached !
 Voltage is all I have.   But Specific Gravity is the gold standard test. (at a specific temperature)

This is the chart that I use  every time I need to use one.