What is the AGM Wall?
Mex described the "wall" one way, and LY describes it another way. LY quote: "My TPPL agm responds so well to the high amp recharge from a well depleted state that when I notice performance loss...
Forum Discussion
I consider a regular full charge to be when amps taper to 0.5% of capacity at Vabs, which is 0.45 amps on my 90Ah rated battery
Since I have to lower voltage manually, well I have left it overnight at 14.7v, more than once, unintentionally.
When the battery was new, eventually at 14.7v, the amps would taper to somewhere less than 0.05.
NOw at 800 Deep cycles and approaching 5 years of age, if I forget and leave it overnight at 14.7v, amps will taper to 0.2ish
When I do a bunch of PSOC cycling and the battery is showing lesser voltages during the same AH removed I might see amps toggling between 0.4 and 0.3, I'll let it go a while longer, seeing if I can get 0.2.
When I return 10 to 15 minutes later, if the amps are 0.4 I quit Vabs, if it is solid 0.3 I will see if it toggles between 0.3 and 0.2. in another 15 to 20 minutes.
If it stops tapering or if amps start rising I quit Vabs.
Right now I consider 0.2a to be my Northstar AGM's wall. This is a TPPL AGM, thin plate pure lead, Like Odyssey AGM.
I have no Idea what your UPG AGM batteries wall will be or whether you should be seeking to find it with that brand.
If I want to hit the wall but it stops tapering at 0.3, and I have been doing lots of low and slow solar recharges to full, or perhaps not to full(0.45a), or obviouslyt no where near full, then I will intentionally drain well below 50% and hammer it with no less than 40 amps but hopefully 65.
When I hammer it with high amps from well belwo 50%, it then takes less time for amps to taper to 0.45, compared to if I had done a ~35 amp recharge from say 60% state of charge.
My battery will gain significant temperature with 65 amps into a 90AH battery.
I adjust voltage downward manually accordingly.
High amp recharges on this battery usually lower the amperage wall if I choose to see if i can hit it, or if I forget and leave it up high overnight.
Some might say I am overcharging. I do not do this every time, no more than 2x a month and not recently as it has been a warm summer.
If you choose to hold Vabs to see just how low the amps can taper to, it is another data point to compare to a later data point, but you want to know if it is still tapering and stop Vabs when it starts rising, preferably before. I've rarely seen amps begin rising and only within the last say 60 deep cycles when I've tried to see if the wall is still 0.2 and hopefully less.
I'd be happier if my Wall were back in the 0.05amp or less range, It is now somewhere between 0.2a and 0.3a, and 'full' is 0.45a.
Your battery will be different.
Since I have to lower voltage manually, well I have left it overnight at 14.7v, more than once, unintentionally.
When the battery was new, eventually at 14.7v, the amps would taper to somewhere less than 0.05.
NOw at 800 Deep cycles and approaching 5 years of age, if I forget and leave it overnight at 14.7v, amps will taper to 0.2ish
When I do a bunch of PSOC cycling and the battery is showing lesser voltages during the same AH removed I might see amps toggling between 0.4 and 0.3, I'll let it go a while longer, seeing if I can get 0.2.
When I return 10 to 15 minutes later, if the amps are 0.4 I quit Vabs, if it is solid 0.3 I will see if it toggles between 0.3 and 0.2. in another 15 to 20 minutes.
If it stops tapering or if amps start rising I quit Vabs.
Right now I consider 0.2a to be my Northstar AGM's wall. This is a TPPL AGM, thin plate pure lead, Like Odyssey AGM.
I have no Idea what your UPG AGM batteries wall will be or whether you should be seeking to find it with that brand.
If I want to hit the wall but it stops tapering at 0.3, and I have been doing lots of low and slow solar recharges to full, or perhaps not to full(0.45a), or obviouslyt no where near full, then I will intentionally drain well below 50% and hammer it with no less than 40 amps but hopefully 65.
When I hammer it with high amps from well belwo 50%, it then takes less time for amps to taper to 0.45, compared to if I had done a ~35 amp recharge from say 60% state of charge.
My battery will gain significant temperature with 65 amps into a 90AH battery.
I adjust voltage downward manually accordingly.
High amp recharges on this battery usually lower the amperage wall if I choose to see if i can hit it, or if I forget and leave it up high overnight.
Some might say I am overcharging. I do not do this every time, no more than 2x a month and not recently as it has been a warm summer.
If you choose to hold Vabs to see just how low the amps can taper to, it is another data point to compare to a later data point, but you want to know if it is still tapering and stop Vabs when it starts rising, preferably before. I've rarely seen amps begin rising and only within the last say 60 deep cycles when I've tried to see if the wall is still 0.2 and hopefully less.
I'd be happier if my Wall were back in the 0.05amp or less range, It is now somewhere between 0.2a and 0.3a, and 'full' is 0.45a.
Your battery will be different.
