Question: if the wet cell battery shows 12.46 volts after trickle charging for 24 hours is there a way to boost it to 12.6 volts so that it is 100% charged? All cells appear to have the same specific gravity. Just wondering if because the battery is two years old it will never recharge to 100%.
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A small part of the problem is your concern
about .14 volts. It really isn't a big deal. My group 31 AGM batteries won't hold above 12.25 volts but they will hold that all winter. I can run for three hours with my alternator and that's where we stay.
about .14 volts. It really isn't a big deal. My group 31 AGM batteries won't hold above 12.25 volts but they will hold that all winter. I can run for three hours with my alternator and that's where we stay.
This might help
Level SpecGravity Voltage 100% 1.265 12.7 *75% 1.225 12.4 50% 1.190 12.2 25% 1.155 12.0 Discharged 1.120 11.9 *Sulfation of Batteries starts when specific gravity falls below 1.225 or voltage measures less than 12.4 (12v Battery) or 6.2 (6 volt battery). Sulfation hardens the battery plates reducing and eventually destroying the ability of the battery to generate Volts and Amps. See link for a more complete explanation
Level SpecGravity Voltage 100% 1.265 12.7 *75% 1.225 12.4 50% 1.190 12.2 25% 1.155 12.0 Discharged 1.120 11.9 *Sulfation of Batteries starts when specific gravity falls below 1.225 or voltage measures less than 12.4 (12v Battery) or 6.2 (6 volt battery). Sulfation hardens the battery plates reducing and eventually destroying the ability of the battery to generate Volts and Amps. See link for a more complete explanation
It also depends on where the voltage
if being measured. You will not get a true battery reading unless there is no current coming from the battery. Current draw automatically cause a slight (or not so slight if the draw is large) drop in voltage. If you are measuring the voltage at a buss and not at the terminal there is an additional drop for each connection both to and from the battery. 0.1 volts per connection is standard for planning purposes. If there is no current draw then it does not matter where you measure the voltage. I've seen a digital clock (0.02 amp draw) cause the voltage to drop 0.1 volts and most clocks are wired so you can't turn them off. I'd not worry about it.
if being measured. You will not get a true battery reading unless there is no current coming from the battery. Current draw automatically cause a slight (or not so slight if the draw is large) drop in voltage. If you are measuring the voltage at a buss and not at the terminal there is an additional drop for each connection both to and from the battery. 0.1 volts per connection is standard for planning purposes. If there is no current draw then it does not matter where you measure the voltage. I've seen a digital clock (0.02 amp draw) cause the voltage to drop 0.1 volts and most clocks are wired so you can't turn them off. I'd not worry about it.
A voltage of 12.46 indicates a charge of
approximately 84%. This probably comes as a result of sulfation. Some smart battery chargers come with a battery reconditioning cycle which by supplying a low level charge over a 24 hour period tends to break up sulfation. I found a rather inexpensive automotive smart Vector charger that has the reconditioning cycle. A treatment once every couple of months should optimize your batts. I do not think you will regain 100% charge on the two year old batteries but at least if you could perhaps get to 90% or 12.5V you may get a couple of more years of use out of them. Sulfation usually comes a result of multiple charge/discharge cycles and allowing a battery to sit in a partially discharged condition for some time. By giving up 15% of your batteries storage capacity you are in effect reducing the size of your banks. Wether you keep them batteries or not depends on your usage. Some sailors with deep banks would hardly notice a 10% loss while others with a single battery house bank cannot afford to give away any.
approximately 84%. This probably comes as a result of sulfation. Some smart battery chargers come with a battery reconditioning cycle which by supplying a low level charge over a 24 hour period tends to break up sulfation. I found a rather inexpensive automotive smart Vector charger that has the reconditioning cycle. A treatment once every couple of months should optimize your batts. I do not think you will regain 100% charge on the two year old batteries but at least if you could perhaps get to 90% or 12.5V you may get a couple of more years of use out of them. Sulfation usually comes a result of multiple charge/discharge cycles and allowing a battery to sit in a partially discharged condition for some time. By giving up 15% of your batteries storage capacity you are in effect reducing the size of your banks. Wether you keep them batteries or not depends on your usage. Some sailors with deep banks would hardly notice a 10% loss while others with a single battery house bank cannot afford to give away any.
Trickle Charging won't work
What you need is an equalization charge. All the cells are not equal in charge or state of the plates. Also the electrolyte needs a good shake up as over time it tends to layer with different specific gravities. And no heeling your boat wont' fix that. A higher amp and or volt charge every couple of months boils the electrolyte a little to mix things up and equalizes the voltage in each cell. I have 24 deep cycle batteries in various banks for a number of solar power systems in my blacksmith shop/home/print shop/pottery shop/ boat(system is also used for camping). We equalize at least twice a year, sometimes more if we have had consistently low charging from low light levels. Trickle charging alone cannot maintain a battery over the long haul, nor cannot it bring a battery upto a true full charge, especially not from a fully discharged state. You need more amps and perhaps more voltage. One of my charge controllers for the solar stuff does this automatically, the other banks have to be manually charged with a separate charger, 20 amps minimum. 14.7 volts will push more juice.
What you need is an equalization charge. All the cells are not equal in charge or state of the plates. Also the electrolyte needs a good shake up as over time it tends to layer with different specific gravities. And no heeling your boat wont' fix that. A higher amp and or volt charge every couple of months boils the electrolyte a little to mix things up and equalizes the voltage in each cell. I have 24 deep cycle batteries in various banks for a number of solar power systems in my blacksmith shop/home/print shop/pottery shop/ boat(system is also used for camping). We equalize at least twice a year, sometimes more if we have had consistently low charging from low light levels. Trickle charging alone cannot maintain a battery over the long haul, nor cannot it bring a battery upto a true full charge, especially not from a fully discharged state. You need more amps and perhaps more voltage. One of my charge controllers for the solar stuff does this automatically, the other banks have to be manually charged with a separate charger, 20 amps minimum. 14.7 volts will push more juice.
Bob, are you trying to fire-up the masses?
You sure left out a lot of stuff. Like how big of a battery and how much was it charged when you started and what was the trickle charger putting out. There's other considerations too but most of all you seem to be thinking that a trickle charger is a real battery charger. A trickle charger is only for maintaining a CHARGE in a fully CHARGED battery. Yours isn't. And because it's a TRICKLE charger, by definition, 24 hours won't do it. Yep, the masses are fired-up.
You sure left out a lot of stuff. Like how big of a battery and how much was it charged when you started and what was the trickle charger putting out. There's other considerations too but most of all you seem to be thinking that a trickle charger is a real battery charger. A trickle charger is only for maintaining a CHARGE in a fully CHARGED battery. Yours isn't. And because it's a TRICKLE charger, by definition, 24 hours won't do it. Yep, the masses are fired-up.
the question's intent was how to increase the
The batteries in question are group 24, wet cell, Sears Marine Deep Cycle, about 2 years old. They managed to be drawn down over the summer from the refrigeration and not seeing shore power for the onboard charger all summer. So will equalization bring them back and is battery charger able to accomplish this task? The batteries are off the boat and at home in the basement.
The batteries in question are group 24, wet cell, Sears Marine Deep Cycle, about 2 years old. They managed to be drawn down over the summer from the refrigeration and not seeing shore power for the onboard charger all summer. So will equalization bring them back and is battery charger able to accomplish this task? The batteries are off the boat and at home in the basement.
What's the Rush??
Leave the trickle charger on for a couple of days. See if the battery improves. If trickle means 1-2 amps do the math. A flat dead 110 AH should take over 4 days with a 1 amp charger and that assumes 100% efficency.
Leave the trickle charger on for a couple of days. See if the battery improves. If trickle means 1-2 amps do the math. A flat dead 110 AH should take over 4 days with a 1 amp charger and that assumes 100% efficency.
I'd agree that a trickle charger is not the proper
I'd have to agree that a trickle charger is not the proper charger to achieve the max. life or charge on a battery bank. You need a charger that can output the proper charge and condition your batteries. Something like a Statpower/Xantrex True Charger 20/40 will do the job. A good charger can even extend the life of cheap batteries.
I'd have to agree that a trickle charger is not the proper charger to achieve the max. life or charge on a battery bank. You need a charger that can output the proper charge and condition your batteries. Something like a Statpower/Xantrex True Charger 20/40 will do the job. A good charger can even extend the life of cheap batteries.
Battery testing
Now that the boat is on the hard for winter and the batteries are several yyears old, I would like to test them WITHOUT removing them. Baateries, humans and ladders don't mix very well. Other than taking the batteries out and to a Batteries Plus type store for testing, does anyone have a recommendation to test the battery condition?
Now that the boat is on the hard for winter and the batteries are several yyears old, I would like to test them WITHOUT removing them. Baateries, humans and ladders don't mix very well. Other than taking the batteries out and to a Batteries Plus type store for testing, does anyone have a recommendation to test the battery condition?
Good battery hydrometer and voltmeter
A good hydrometer to measure specific gravity and good voltmeter to check voltage. Test an hour or so after charging. See above posts for good sg and voltage reccomendations.
A good hydrometer to measure specific gravity and good voltmeter to check voltage. Test an hour or so after charging. See above posts for good sg and voltage reccomendations.
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