AGM vs Flooded Bulk Times
PT keeps asking whether AGMs will spend more time in Bulk at the same charging rate. I found a good example where that can be measured, using ah64id's test with his PD4655 on his pair of Lifeline...
Forum Discussion
I think you all also forget that internal construction of the battery and plate thickness will affect the "take" rate of amps at 14.4v for surplus telecom AGM or 14.8V for vented golf cart type batteries.
No matter what I do, with my 150 amp 12v Deka surplus telecom AGM battery that is acid rich and designed for a 10 year telecom cell site lifetime in emergency use, it does not seem to be able to take more that 20 amps at 14.4v setting from my MegaWatt 30 amp model, complete with amp hour readings and total amp hours taken on board. It's a far cry slower that my Trojan T-1275 that was also 150 amp hours. But it's plates are much, much thicker, and it delivers much less amperage surge than my T-1275 ever did. It just doesn't, by design, generate a lot of surge dishcharge capacity. And it doesn't have a lot of surge charge capacity either. Now lots of thinner plates in AGM will recharge much faster, more square inches of lead plate inside for chemistry to allow for quicker discharge and recharge rates. Know what you are buying before you plunk down for a surplus AGM, they all are not created equally. I bought a 10 year life surplus AGM battery with plates thick as the dickens, that doesn't put out a tremendous amount of surge amps. But it will last a long, long time, and it will last a lot of cycles, with those big, thick heavy lead plates in it. I zap charge it with a generator and a full 20 amps every 5 days, and solar panel does the rest at 8 to 9 amps /hour daily, when boondocking. It always goes home with me at the end of the trip and gets charged up fully, until it, being a 150amp hr battery, will take .75 amp hour charge rate at 14.4v. It does just fine in storage, very, very little loss of charge from month to month. Also of note, it does not active my magnetic brakes on the trailer very well, so I run another battery out back while driving, a flooded lead acid group 24, that will work my electric brakes.
No matter what I do, with my 150 amp 12v Deka surplus telecom AGM battery that is acid rich and designed for a 10 year telecom cell site lifetime in emergency use, it does not seem to be able to take more that 20 amps at 14.4v setting from my MegaWatt 30 amp model, complete with amp hour readings and total amp hours taken on board. It's a far cry slower that my Trojan T-1275 that was also 150 amp hours. But it's plates are much, much thicker, and it delivers much less amperage surge than my T-1275 ever did. It just doesn't, by design, generate a lot of surge dishcharge capacity. And it doesn't have a lot of surge charge capacity either. Now lots of thinner plates in AGM will recharge much faster, more square inches of lead plate inside for chemistry to allow for quicker discharge and recharge rates. Know what you are buying before you plunk down for a surplus AGM, they all are not created equally. I bought a 10 year life surplus AGM battery with plates thick as the dickens, that doesn't put out a tremendous amount of surge amps. But it will last a long, long time, and it will last a lot of cycles, with those big, thick heavy lead plates in it. I zap charge it with a generator and a full 20 amps every 5 days, and solar panel does the rest at 8 to 9 amps /hour daily, when boondocking. It always goes home with me at the end of the trip and gets charged up fully, until it, being a 150amp hr battery, will take .75 amp hour charge rate at 14.4v. It does just fine in storage, very, very little loss of charge from month to month. Also of note, it does not active my magnetic brakes on the trailer very well, so I run another battery out back while driving, a flooded lead acid group 24, that will work my electric brakes.
