How to boost charge AGM batteries in storage?
The manual for my Lifeline 100 Amp Hour Deep Cycle AGM 12 volt batteries says this:
"While in storage, batteries should be boost charged every 90 days or when open circuit voltage drops to 12.5 volts for a 12 volt battery. Boost charge batteries using a constant voltage charger set to 14.4 to 15.0 volts for a 12 volt battery. The boost charge should be applied until the charging current falls below 0.5 percent of the battery's 20 hour rated capacity (0.5 amps for a 100 Ah battery)."
I don't understand this at all. What is a boost charge? What is a constant voltage charger? How do I measure when the charging current falls below 0.5 percent?
So I tried calling the battery technical support, but it didn't help. He said several things. He said a cheap battery charger from Walmart might not be able to get up to the required 14.4 to 15.0 volts. He recommended a specific charger and said there is a boost charge button. He said just press that button and it will do what is needed.
But then I looked up the recommended charger and there is no boost charge button. Rather, it is one of these fully automatic battery chargers with no buttons at all. Also when I got to the 5th review on Amazon saying that this charger overcharged and boiled their AGM batteries I decided to believe it and stay away from this specific charger.
So where do I get a charger with "constant voltage boost charge" capability? Well, he also said that boost charge is just the first stage of a 3 stage charger. So does that mean I can just get any 3 stage charger and it will boost charge the batteries, then harmlessly let it go into the other 2 stages? That actually there isn't any special charger needed?
Also, that the manual says the boost charge should be applied until the charging current falls below 0.5 percent. He said that only high end chargers will say the charging current. Including the specific charger he recommended doesn't have this feature, so he said don't worry about that. I suppose because a smart charger knows when to cut off.
I am still completely lost about what I need to do. Do I need a special charger or will any charger that supports AGM batteries do what is needed? Most battery chargers are completely automatic, so will it automatically do what I need? Maybe the battery manual quote above is only confusing words (saying to use a constant voltage charger set to specific volts) where actually any battery charger will do what is needed?
If someone could even recommend a specific charger, maybe something available on Amazon, that would be greatly appreciated. There are so many battery chargers around it is hard to pick a specific one. My needs are minimal, only to boost charge the batteries while in storage once every 90 days at most, so a low end charger should be enough... if it has the features that are required (and does not have a reputation for boiling AGM batteries).
I am completely lost and hoping someone can help. Thanks!
"While in storage, batteries should be boost charged every 90 days or when open circuit voltage drops to 12.5 volts for a 12 volt battery. Boost charge batteries using a constant voltage charger set to 14.4 to 15.0 volts for a 12 volt battery. The boost charge should be applied until the charging current falls below 0.5 percent of the battery's 20 hour rated capacity (0.5 amps for a 100 Ah battery)."
I don't understand this at all. What is a boost charge? What is a constant voltage charger? How do I measure when the charging current falls below 0.5 percent?
So I tried calling the battery technical support, but it didn't help. He said several things. He said a cheap battery charger from Walmart might not be able to get up to the required 14.4 to 15.0 volts. He recommended a specific charger and said there is a boost charge button. He said just press that button and it will do what is needed.
But then I looked up the recommended charger and there is no boost charge button. Rather, it is one of these fully automatic battery chargers with no buttons at all. Also when I got to the 5th review on Amazon saying that this charger overcharged and boiled their AGM batteries I decided to believe it and stay away from this specific charger.
So where do I get a charger with "constant voltage boost charge" capability? Well, he also said that boost charge is just the first stage of a 3 stage charger. So does that mean I can just get any 3 stage charger and it will boost charge the batteries, then harmlessly let it go into the other 2 stages? That actually there isn't any special charger needed?
Also, that the manual says the boost charge should be applied until the charging current falls below 0.5 percent. He said that only high end chargers will say the charging current. Including the specific charger he recommended doesn't have this feature, so he said don't worry about that. I suppose because a smart charger knows when to cut off.
I am still completely lost about what I need to do. Do I need a special charger or will any charger that supports AGM batteries do what is needed? Most battery chargers are completely automatic, so will it automatically do what I need? Maybe the battery manual quote above is only confusing words (saying to use a constant voltage charger set to specific volts) where actually any battery charger will do what is needed?
If someone could even recommend a specific charger, maybe something available on Amazon, that would be greatly appreciated. There are so many battery chargers around it is hard to pick a specific one. My needs are minimal, only to boost charge the batteries while in storage once every 90 days at most, so a low end charger should be enough... if it has the features that are required (and does not have a reputation for boiling AGM batteries).
I am completely lost and hoping someone can help. Thanks!
