AC DC Adaptor fail

Battery state
12.75v stand alone
12.86v connected to charger
10.21 m-Ohm internal resistance
46% wear life (based on 340EN 374CCA)
254 CCA
Spec: Lion 063 40Ah EN 340CCA, very old

Charger state (no adjustments from previous)
25mA effective charge current
1.5w mains draw
32v open circuit
32mA open circuit
 
Battery state
12.87v stand alone
13v connected to charger
9.79 m-Ohm internal resistance
50% wear life (based on 340EN 374CCA)
264 CCA
Spec: Lion 063 40Ah EN 340CCA, very old

Charger state (no adjustments from previous)
24mA effective charge current
0.312w max effective charge power - 24mA * 13v = 0.312w
1.5w mains draw
32.5v open circuit
33mA open circuit

The CCA gain slowed and then bounced off the top of around 266. The existing charger configuration has reached the limit of what it can do. Next up is bumping the charge current to 35mA effective. It's apparent that having high voltage alone is not enough for charging a battery fully. I think the charging wattage also matters. It is also apparent that it is not the charging voltage that causes gassing. Up to now, there has been no gassing from the high charger voltage.
 
My initial expectation of 275cca has been achieved. I won't be able to find out if the battery can do better because I need the battery to go do an MOT. After I will leave it in the car to run down by the winter. With such low capacity, it will not survive the winter.

Battery state
13.16v stand alone
13.36v connected to charger
9.42 m-Ohm internal resistance
54% wear life (based on 340EN 374CCA)
275 CCA
Spec: Lion 063 40Ah EN 340CCA, very old

Charger state (charge current adjusted up from previous)
37mA effective charge current
0.494w max effective charge power
1.8w mains draw
32.54v open circuit
42mA open circuit
 
jesus mate- you are tilting at windmills at this point. Respect for checking the stats, but do think anyone else cares a jot?
 
Happy news for the regular followers of this thread, such as opps. The cca has broken through the minimum I was expecting, and now stands at 278. The sky could be the limit. Of course, I am deliriously overoptimistic. Who would have thought battery charging can be such a fun mystery?
 
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The battery was doing rather well. But, I had to take it off charge to go do an MOT. Passed as expected. A new baseline has been established for the battery using the final reading. The battery has greater capacity than that.

Battery state
13.34v stand alone
13.5v connected to charger
8.89 m-Ohm internal resistance
61% wear life (based on 340EN 374CCA)
292 CCA
Spec: Lion 063 40Ah EN 340CCA, very old

Charger state (no change from previous)
36mA effective charge current
0.486w max effective charge power
1.5 - 1.8w mains draw
32.48v open circuit
40mA open circuit
 
The battery swapped out from the car is the 075 that appeared previously in the thread. Lost of sun solar meant that it cannot sustain itself in an infrequently driven car and starts with hesitation. This goes on charge using the same charger configuration I have been using.

Battery state
12.09v stand alone
11.85 m-Ohm internal resistance
21% wear life (based on 435EN 475CCA)
218 CCA
Spec: Powerline 075 435EN, very old
 
Battery state
12.51v stand alone
12.6v connected to charger
10.14 m-Ohm internal resistance
29% wear life (based on 435EN 475CCA)
256 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (no change from previous)
36mA effective charge current
0.45w max effective charge power
1.5 - 1.8w mains draw
32.47v open circuit
40mA open circuit
 
Are you a member of the Dull Mens club by any chance?
I'm sure they would love you on there.
 
Battery state
12.66v stand alone
12.76v connected to charger
No gassing while connected to charger
9.05 m-Ohm internal resistance
36% wear life (based on 435EN 475CCA)
286 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (no change from previous)
37mA effective charge current
0.47w max effective charge power
1.5 - 1.8w mains draw
32.5v open circuit
42mA open circuit

This is too dull even for me. Low current charging is very likely OK for a permanent connection so long as there is no gassing. After this reading, I have dialed up the charge current to 200mA. This did not produce any immediate gassing. I have just formed a new theory, that the charge voltage and current can be as high as you want so long as there is no gassing. I expect gassing to occur closer to battery charge full. At that point, the charge current can be dialed back down for a permanent charging connection, which might be useful for reclaiming lost capacity.

Charging lead acid is not dull at all. It is very, very exciting, with new knowledge frontiers to be broken into.
 
As predicted by my brand new theory, there is no gassing from 5x increase in the charging current. After this reading, I am increasing the current another 2x to 400mA effective. Again, I am expecting no gassing at tomorrow's reading. The battery capacity is known to be at 400cca. I expect gassing to begin closer to that. The cca should reach 350'ish tomorrow.

Battery state
12.85v stand alone
13.07v connected to charger
No gassing while connected to charger
8.42 m-Ohm internal resistance
42% wear life (based on 435EN 475CCA)
307 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (5x increased current from previous)
196mA effective charge current
2.56w max effective charge power
4.5w mains draw
32.48v open circuit
199mA open circuit
 
Turns out there is a limit to how much charging current can be used. This limit is likely to be dependant on the charge state of the battery. At 400mA, some gassing is produced. Gassing negatively impacts charging. Therefore it is undesirable. After this reading, I have dialled back the charging current to 200mA to remove gassing. I will dial further back as necessary. Gassing can be detected by the sound of hydrogen bubbles bursting in the electrolyte. More bursts, worst the gassing. Gassing indicates the battery is unable to accept all of the supplied energy into the plates. The excess in the energy feed then forms the hydrogen bubbles through electrolysis.

Battery state
13.25v stand alone
13.65v connected to charger
Some gassing while connected to charger
7.71 m-Ohm internal resistance
50% wear life (based on 435EN 475CCA)
336 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (2x increased current from previous)
391mA effective charge current
5.34w max effective charge power
7.9-8.2w mains draw
32.45v open circuit
401mA open circuit
 
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Battery state
13.53v stand alone
13.81v connected to charger
Some gassing while connected to charger
7.31 m-Ohm internal resistance
56% wear life (based on 435EN 475CCA)
354 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (halved current from previous to reduce gassing)
198mA effective charge current
2.73w max effective charge power
4.5-4.8w mains draw
32.43v open circuit
200mA open circuit
 
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