Hi guys

Does anyone have some information about the charging efficiency of the top 20% of a SLA battery?

I am working on a solar project, from the information I get, it's a good idea to work with the top 20% of the capacity of a SLA battery.

And now I am working on how much energy do I need to top that 20% up.

Thanks guys!

edit:

when I said top 20%, I mean from 80% of state of charge to near 100% state of charge.

 

The top 20% would be from 20% of the amp-hour battery rating.

 

Sir, I believe you have misinterpreted the question. The "rule of thumb" that I last heard was that it takes 150% input to recharge a lead acid battery. That might be wrong, but 10 amp hours in to replace 10 amp hours out seems impossible because it represents 100% efficiency. The fact that a battery gets warm when you charge it belies that.

May I suggest http://batteryuniversity.com/

and see if that site has a useful figure?

 

Hi #12,

I have been to the batteryuniversity.com, I don't find the information I need.

 

This page says the loss is 5%.
http://evbatterymonitoring.com/WebHelp/Section_3.htm

This page says the loss is 15% to 25%
http://wiki.xtronics.com/index.php/Sealed_Lead_Acid_Battery_Applications

This page says the loss is 26%
http://www.futurepundit.com/archives/006554.html

This page says the loss is 40% in the top 20% of the charging and that is exactly a fit for your question.
http://www.solar-facts.com/batteries/battery-charging.php

 

Hi #12,

Thanks a lot, that's very helpful!!

This page says the loss is 5%.
http://evbatterymonitoring.com/WebHelp/Section_3.htm

This page says the loss is 15% to 25%
http://wiki.xtronics.com/index.php/Sealed_Lead_Acid_Battery_Applications

This page says the loss is 26%
http://www.futurepundit.com/archives/006554.html

This page says the loss is 40% in the top 20% of the charging and that is exactly a fit for your question.
http://www.solar-facts.com/batteries/battery-charging.php

 

That's what the "Thanks" button is for.