Author Topic: East Penn AGM Battery DOD  (Read 170 times)

svencool

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East Penn AGM Battery DOD
« on: July 13, 2017, 07:24:52 PM »
I have 4 of these 12v batteries wired in series for 24v. Where can I find a chart showing DOD values for a 24v system at lets say 80%? I've tried to find it on the manf web site with no luck.
Mike

ClassicCrazy

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Re: East Penn AGM Battery DOD
« Reply #1 on: July 13, 2017, 10:09:12 PM »
I have 4 of these 12v batteries wired in series for 24v. Where can I find a chart showing DOD values for a 24v system at lets say 80%? I've tried to find it on the manf web site with no luck.
Mike

Not sure what you mean 80% DOD ?
This shows all the specs for East Penn Deka batteries.
http://www.eastpennmanufacturing.com/wp-content/uploads/Renewable-Energy-Charging-Parameters-1913.pdf

Larry
system one
Classic 150 , 20 Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

svencool

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Re: East Penn AGM Battery DOD
« Reply #2 on: July 14, 2017, 04:19:31 AM »
DOD = Depth of Discharge was just asking on AGM's what would the resting battery voltage be lets say your batteries were topped off and if you pulled 20% out of your 24v battery bank? What would or should they read?

Mike

ClassicCrazy

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Re: East Penn AGM Battery DOD
« Reply #3 on: July 14, 2017, 01:03:28 PM »
DOD = Depth of Discharge was just asking on AGM's what would the resting battery voltage be lets say your batteries were topped off and if you pulled 20% out of your 24v battery bank? What would or should they read?

Mike

You can't  tell the battery state of charge by looking at the voltage . That is why you need something like the Whizbang to count what goes in and out of the battery to calculate the SOC. 

Larry
system one
Classic 150 , 20 Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

svencool

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Re: East Penn AGM Battery DOD
« Reply #4 on: July 14, 2017, 05:55:16 PM »
I have a Whizbang and a Trimetric meter but I like to validate those meters as they are just a guess..... Thanks

Mike

ClassicCrazy

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Re: East Penn AGM Battery DOD
« Reply #5 on: July 14, 2017, 08:55:07 PM »
I have a Whizbang and a Trimetric meter but I like to validate those meters as they are just a guess..... Thanks

Mike

The Whizbang and Trimetric will always be a better guess than trying to figure it out from voltage. There isn't a way to do that. When I first started in solar there were some curves for flooded lead acid  and depending on what the load or charge amps were you could take a guess but the graph was not linear and of course everything was temperature dependent. I have never seen anything for resting voltages. AGM's there is no way to verify like you can with flooded by taking specific gravity. And from what I have seen on some AGM they can show a good resting voltage when they are dead for capacity.

Larry
system one
Classic 150 , 20 Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

svencool

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Re: East Penn AGM Battery DOD
« Reply #6 on: July 14, 2017, 09:24:34 PM »
Well I've noticed that if they read lets say 24.6v while in use. After disconnecting the load they go up to 24.9 or so afterwards. I have a 200ah battery bank at 24v. If watching the whizbang it usually ends up being around 188ah or so. So if I used 20% it should read 160ah right? As I'm trying to get the most milage out of my batteries :)

Mike
« Last Edit: July 14, 2017, 09:26:47 PM by svencool »

ClassicCrazy

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Re: East Penn AGM Battery DOD
« Reply #7 on: July 14, 2017, 10:49:59 PM »
The Classic / Whizbang compensates battery capacity based on temperature of the battery pack too.
To get the most life out of batteries you keep them cool , try to only discharge no more than 20% of capacity, and make sure that any parallel batteries wiring is balanced so the loads and charge are the same across all of them.

At least that is what I have gathered from all available info .

Yeah your calculations sound right .

Larry 
system one
Classic 150 , 20 Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

svencool

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Re: East Penn AGM Battery DOD
« Reply #8 on: July 14, 2017, 11:00:17 PM »
Thanks Larry! and Yes 2 sets of batteries in series only to be connected in Parallel via a buss bar. I've measured each line and made sure I would get them as close as possible to the same length and resistance level....

Mike

Highflyer

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Re: East Penn AGM Battery DOD
« Reply #9 on: September 16, 2017, 07:37:23 PM »
How about a hydrometer to check Specific Gravity of the cells?  Wouldn't that give you a very good state of charge?
Brian

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