galladanb
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By that I mean, if 100% full equals 12.x???
12.5 = ???
12.4 = ???
Does that make sense?
12.5 = ???
12.4 = ???
Does that make sense?
Battery system voltages...
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jonyjoe303
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galladanb
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Does this same chart apply to two 6v's mated as a 12v pair?
SternWake
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Voltage only relates to state of charge exactly, on a rested battery, one which has not seen charging or loads applied for a long time.
Also batteries will have slightly differnet full charge resting voltages. My Northstar AGMN rests at 13.06v when fully charged, so saying that 12.73v is 100% chrged is totally wrong, on this battery.
Golf cart batteries generally rest at about 12.7v when fully chrged and healthy and at about 75f.
Voltage is a general guide.
Thinking that voltage can correspond directly to a % state of charge on a battery in use or one that has not rested for a long time is .....unwise.
With many observations of voltage held under known loads and startng at a full charge, then one can see 12.4 under a 3 amp load and make an educated guess as to state of charge, but driving for 5 minutes shutting off the engine and seing 12.8v does NOT mean the battery is fully charged. If Disconnected from all loads and charging sources for 24 hours, that 12.8v might drop to 12.3v.
Voltage does not accurately indicate state of charge on anything but a rested battery, and that specific battery's full chrarge resting voltage needs to be known, as full chrge voltage can vary widely from battery to battery. I;ve personally seen 12.62 to 13.16 as full chrge resting voltages on different batteries.
battery temperature also plays a big part.
Avoid thinking X voltage = X state of charge exactly It only works on a rested battery, otherwise it is a general estimate.
Also batteries will have slightly differnet full charge resting voltages. My Northstar AGMN rests at 13.06v when fully charged, so saying that 12.73v is 100% chrged is totally wrong, on this battery.
Golf cart batteries generally rest at about 12.7v when fully chrged and healthy and at about 75f.
Voltage is a general guide.
Thinking that voltage can correspond directly to a % state of charge on a battery in use or one that has not rested for a long time is .....unwise.
With many observations of voltage held under known loads and startng at a full charge, then one can see 12.4 under a 3 amp load and make an educated guess as to state of charge, but driving for 5 minutes shutting off the engine and seing 12.8v does NOT mean the battery is fully charged. If Disconnected from all loads and charging sources for 24 hours, that 12.8v might drop to 12.3v.
Voltage does not accurately indicate state of charge on anything but a rested battery, and that specific battery's full chrarge resting voltage needs to be known, as full chrge voltage can vary widely from battery to battery. I;ve personally seen 12.62 to 13.16 as full chrge resting voltages on different batteries.
battery temperature also plays a big part.
Avoid thinking X voltage = X state of charge exactly It only works on a rested battery, otherwise it is a general estimate.
galladanb
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Ok, that makes sense.
So, how will I know if and when they are fully up?
I want to find the fullest point so I can calibrate my meter? If I knew how to do that...
So, how will I know if and when they are fully up?
I want to find the fullest point so I can calibrate my meter? If I knew how to do that...
SternWake
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temperature compesated Hydrometer for flooded batteries.
AGM, when a 100AH AGM battery can only accept 0.5 amps or less at 14.4 to 14.7v then it can be considered fully charged. This does not work at 13.6v or anything less than absorption voltage.
AGM, when a 100AH AGM battery can only accept 0.5 amps or less at 14.4 to 14.7v then it can be considered fully charged. This does not work at 13.6v or anything less than absorption voltage.
State of Charge battery monitors.
Shunt-based like Trimetric or Victron BMV-702.
Or Merlin/Balmar SmartGauge.
Not perfect but more accurate than using voltages, more convenient than using a hydrometer or ammeter every charge cycle.
But too costly for many, and most consider that level of information unnecessary.
Shunt-based like Trimetric or Victron BMV-702.
Or Merlin/Balmar SmartGauge.
Not perfect but more accurate than using voltages, more convenient than using a hydrometer or ammeter every charge cycle.
But too costly for many, and most consider that level of information unnecessary.
galladanb
Well-known member
I bought this meter...
Bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt
-- Link: http://a.co/dgITRl0
It has me confused by a couple of things.
1.) The voltage changes often, so that mean it is reading the volts at the moment, no history, right?
2.) I thought it was reading the total amp hours used, but last night as I went to check it out during my overnight fridge test, it was reading 3.08ah,
then dropped back to zero, then it went to reading the fridge usage, but it was changing a lot... What am I missing?
3.) I thought if I pulled the power to it, it would reset back to all zero's and start fresh, but it did not... Again, what am I missing here?
4.) I have no idea what the power and energy numbers are or how to make use of them... Ideas, PLEASE???
Sometimes I feel so stupid....
And I feel using the hydrometer every time i want a status check on battery level is quite absurd, and not very convenient.
Not to mention way to messy....
Bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt
-- Link: http://a.co/dgITRl0
It has me confused by a couple of things.
1.) The voltage changes often, so that mean it is reading the volts at the moment, no history, right?
2.) I thought it was reading the total amp hours used, but last night as I went to check it out during my overnight fridge test, it was reading 3.08ah,
then dropped back to zero, then it went to reading the fridge usage, but it was changing a lot... What am I missing?
3.) I thought if I pulled the power to it, it would reset back to all zero's and start fresh, but it did not... Again, what am I missing here?
4.) I have no idea what the power and energy numbers are or how to make use of them... Ideas, PLEASE???
Sometimes I feel so stupid....
And I feel using the hydrometer every time i want a status check on battery level is quite absurd, and not very convenient.
Not to mention way to messy....
If State of Charge is what you're after, see above, SmartGauge is simplest and most accurate, other than the hydrometer.
If a record of total AH in and/or out is what you want, then the shunt-based monitors.
The DMM shows real-time, instantaneous snapshots of amp rates and voltage levels.
If a record of total AH in and/or out is what you want, then the shunt-based monitors.
The DMM shows real-time, instantaneous snapshots of amp rates and voltage levels.
Bob wrote a very good article last July that helps you get "good enough accuracy".
http://www.cheaprvliving.com/blog/monitor-batteries-voltage/
I also use a down and dirty method to calculate battery SOC. I add .40 to the voltage readout to get the percentage SOC. So 12.60 + .40 would be 100%. 12.10 + .40 would be 50%. Not perfect, but close enough for me.
http://www.cheaprvliving.com/blog/monitor-batteries-voltage/
I also use a down and dirty method to calculate battery SOC. I add .40 to the voltage readout to get the percentage SOC. So 12.60 + .40 would be 100%. 12.10 + .40 would be 50%. Not perfect, but close enough for me.
For the more obsessive approach, search for "monitor", three articles on this page
http://www.pbase.com/mainecruising/boat_projects
http://www.pbase.com/mainecruising/boat_projects
galladanb
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Now that I have the solar system installed, up, running, and making juice...
I am again confused...
The system came set up by default, I think for gel batteries.
I changed it to flooded, and settings As seen here in the meters manual...
So... Are these acceptable values for my SAMs club 6v Duracell GC 2's?
I've seen where the equalization would be different,
And which value is absorb?
What are the disconnect, reconnect, and discharge values mean that they are showing???
Should I change any of these settings, and if so, which ones and to what value?
Or can they be changed?
I didn't make any changes other than date and time, and to flooded...
SUCH FUN!!!
I am again confused...
The system came set up by default, I think for gel batteries.
I changed it to flooded, and settings As seen here in the meters manual...
So... Are these acceptable values for my SAMs club 6v Duracell GC 2's?
I've seen where the equalization would be different,
And which value is absorb?
What are the disconnect, reconnect, and discharge values mean that they are showing???
Should I change any of these settings, and if so, which ones and to what value?
Or can they be changed?
I didn't make any changes other than date and time, and to flooded...
SUCH FUN!!!
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user 37446
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markf57 said:
According to those charts you often see on the net' (FLA values), 12.7 is 100% SOC for a rested FLA. your method seems to indicate 12.6, so I'm confused. (That's uhh, normal)
Thanks for Bob's link, I've read it and it makes sense. I would go in between the 2 extremes, when you dont have any more roof area or $$ for more panels, you still need to know the SOC, so that's where the advice of writing the voltages down at night and early am are good, as long as you are not drawing off the batteries like a 12v fridg or some phantom load like an inverter left on. Hopefully a couple times a week test like that plus being aware of solar gain conditions (i.e., rains all week, better get to an ac charger) will be ok.
Charge profile for Duracell GC2s, as per the actual mfg East Penn: charge profile: BULK: 7.425V, ABSORB: 7.275V, FLOAT: 6.75V, EQUALIZE: 7.875V
Doubled when 2S for 12V, adjusted for temps other than 78°
Equalize manually on a schedule
Doubled when 2S for 12V, adjusted for temps other than 78°
Equalize manually on a schedule
also found:
Sam's East Penn made Duracell GC2 is a Deka GC-10 with a Duracell Sticker. The Sam's EGC2 is a Deka GC-15 with a Duracell Sticker.
The recommendations from East Penn, for that battery, in a cycling / off-grid application are. (Note: floats are higher in off-grid than typical golf cart use).
At 12V:
Max Charge Current = 30% or less of Ah capacity (20 hour)
Absorption Voltage = 14.4V - 14.7V
Absorption End Point = Current change over 1 hour period of less than 0.1A
Max Absorption Time = 12 Hours
Float Voltage = 13.8V - 14.1V
Float End Time = No Limit
Equalization = 15.0V to 15.3V
Equalization End Point = Current change over 1 hour period of less than 0.1A
Max Equalization Time = 12 Hours
Temp Compensation = -.018V for every degree °C rise above 25C
Sam's East Penn made Duracell GC2 is a Deka GC-10 with a Duracell Sticker. The Sam's EGC2 is a Deka GC-15 with a Duracell Sticker.
The recommendations from East Penn, for that battery, in a cycling / off-grid application are. (Note: floats are higher in off-grid than typical golf cart use).
At 12V:
Max Charge Current = 30% or less of Ah capacity (20 hour)
Absorption Voltage = 14.4V - 14.7V
Absorption End Point = Current change over 1 hour period of less than 0.1A
Max Absorption Time = 12 Hours
Float Voltage = 13.8V - 14.1V
Float End Time = No Limit
Equalization = 15.0V to 15.3V
Equalization End Point = Current change over 1 hour period of less than 0.1A
Max Equalization Time = 12 Hours
Temp Compensation = -.018V for every degree °C rise above 25C
Optimistic Paranoid
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This world isn said:
A normal lead acid flooded cell, at full charge, will read 2.1xxx with the x's being additional numbers. 6 of them together in a "12 volt" battery will either be 12.6 or 12.7 volts depending on whether you round up or round down.
galladanb
Well-known member
My batteries are the EGC2's, btw....
I'm sorry, but did ANY of the replies above answer ANY of my questions?
And what is my combined amp hour capacity?
Such confusion...
I'm sorry, but did ANY of the replies above answer ANY of my questions?
And what is my combined amp hour capacity?
Such confusion...
galladanb said:
Yes, seems to me lots of relevant info, here's a repeat/summary.
Voltage is not how you calibrate an SoC meter.
If FLA, use a hydrometer.
Or, charge per mfg specs until amps decline to X% of AH capacity, e.g. .015C, 1.5A per 100AH.
That is full. Tell your coulomb-counting monitor that is full.
Or get a SmartGauge, which is more accurate and doesn't require frequent recalibration.
If this doesn't help, ask specific clarifying Q's, or maybe you need to clarify what you're looking for.
Now I'm confused. Are you asking how to read a label and add the numbers up?galladanb said:
That is incredibly cheap. Did it come with good instructions? Likely no one in the supply chain who speaks English is reachable.galladanb said:
> The voltage changes often, so that mean it is reading the volts at the moment, no history, right?
Volts are a realtime data point. Some much more expensive monitors display or let you download historical data.
> I thought it was reading the total amp hours used, but last night as I went to check it out during my overnight fridge test, it was reading 3.08ah, then dropped back to zero, then it went to reading the fridge usage, but it was changing a lot...
Amps are also realtime flow rate, see above as with voltage.
Amp Hours are quantity over time. The meter must track AH, but maybe it only uses the data internally to estimate % SoC.
> I thought if I pulled the power to it, it would reset back to all zero's and start fresh, but it did not.
They state that as a feature. Maybe there is a reset function?
> I have no idea what the power and energy numbers are or how to make use of them... Ideas, PLEASE???
You would benefit by googling for tutorials, or reading books that give 101-level DC electrics education.
> And I feel using the hydrometer every time i want a status check on battery level is quite absurd, and not very convenient. Not too mention way to messy
Different strokes, many love the low cost and accuracy. Or use the Ammeter method while charging as outlined above.
With a good AH-counting SoC monitor you only need to calibrate periodically.
With a SmartGauge never.
Reference EGC2 battery by Duracell. New they are 6 volts, 230 amp hour at 20 hour rate. Two connected in series is 12 volts, 230 amp hour. Two sets of series then connected in parallel is 460 amp hour at 12 volts. Set your solar charge controller to 14.7 or 14.8 bulk charging rate, which ever your unit allows.
