AGM battery quality vs cost. Do your research.

john61ct

Adventurer
AGM required? Northstar/X2Power, Odyssey, and Lifeline

I 100% disagree with the OP in a true deep and frequent cycling use case.

But you won't get the value return on the extra investment without properly caring for the bank, details not rocket science but also not commonly known.

If sealed units are not required then equivalently top notch FLA units will be cheaper and longer lasting, even better value.
 

67cj5

Man On a Mission
AGM required? Northstar/X2Power, Odyssey, and Lifeline

I 100% disagree with the OP in a true deep and frequent cycling use case.

But you won't get the value return on the extra investment without properly caring for the bank, details not rocket science but also not commonly known.

If sealed units are not required then equivalently top notch FLA units will be cheaper and longer lasting, even better value.
The only real advantage of AGM's is they are robust when it comes to high vibration environs and they can be used indoors and mounted at almost any angle apart from that they are way over weight compared to an FLA and the charge times when it comes to using a smart charger is a PIA, And they cost anything to +30% and more of an equal sized FLA, and an FLA retains a higher Voltage my AGM's have a cycle life of 340/350 @ 50% where as my Duel Purpose Deep Cycle batteries have a cycle life of 600 @ 70% Discharge, Mine are 5 years old and still have 13.4v+ after 24 hours from being taken off the Charger.

And a 115Ah AGM can only be safely discharged to 50% which equals 736Wh where as a 115Ah FLA @ 70% = 1030Wh of useable power. then multiply those figures by the cycle rate of the AGM would equal 257600wh where as the FLA can supply more than 618240wh which is more than 2.4 times the power of an equal sized AGM.
 
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Peter_n_Margaret

Adventurer
And a 115Ah AGM can only be safely discharged to 50%.......
Urban myth. :)
The Fullriver "DCcyclelife" file attached shows the life in cycles at various discharge levels.....
But of course, a 60% discharge delivers double the energy compared with a 30% discharge.
If you calculate life in total energy delivered there is no "cliff" at 50%, or anywhere else.
Cheers,
Peter
OKA196 motorhome.
 

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67cj5

Man On a Mission
Urban myth. :)
The Fullriver "DCcyclelife" file attached shows the life in cycles at various discharge levels.....
But of course, a 60% discharge delivers double the energy compared with a 30% discharge.
If you calculate life in total energy delivered there is no "cliff" at 50%, or anywhere else.
Cheers,
Peter
OKA196 motorhome.
That chart is ridiculous because it ignores the recommended Depth/cycle rate, I to could only discharge my FLA's to 30% and easily get 1500 to 2000 cycles out of them, Real world testing for my FLA's states 600 cycles discharging down to an SOC of 30% having used 70% of the Batteries Capacity. And for my Primium Grade AGM they quote 350 cycles at 50% SOC.

The Facts and Figures I quoted are real world figures relating to Batteries I actually Own not sales pitch figures collected from the Net.
 
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Peter_n_Margaret

Adventurer
That chart is ridiculous because it ignores the recommended Depth/cycle rate, I to could only discharge my FLA's to 30% and easily get 1500 to 2000 cycles out of them, Real world testing for my FLA's states 600 cycles discharging down to an SOC of 30% having used 70% of the Batteries Capacity. And for my Primium Grade AGM they quote 350 cycles at 50% SOC.

The Facts and Figures I quoted are real world figures relating to Batteries I actually Own not sales pitch figures collected from the Net.
I have been using AGMs for 17 years (including Fullriver for 14 years) and in my experience that chart is quite realistic and there is no detriment to using 100% of an AGMs capacity. The important thing is to ensure that they are recharged fully soon afterwards.
Cheers,
Peter
OKA196 motorhome
 

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