AC DC Adaptor fail

[freddiemercurystwin]

Are you a member of the Dull Mens club by any chance?
I'm sure they would love you on there.

No this would be too dull for that.

 

[DiyNutJob]

I have a funny feeling that once gassing starts, it will not stop until whatever is causing it dissipates. The light gassing continues while the charge current is dropped drastically. A power draw from the battery could dissipate it. This points to a net-draw phase is beneficial to charging. I still haven't set up anything to produce a rest or draw phase yet.

Battery state
13.6v stand alone
13.81v connected to charger
Some gassing while connected to charger
7.13 m-Ohm internal resistance
59% wear life (based on 435EN 475CCA)
363 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (halved current from previous to reduce gassing)
100mA effective charge current
1.38w max effective charge power
2.7-3w mains draw
32.48v open circuit
97mA open circuit

 

[DiyNutJob]

Battery state
13.52v stand alone
13.67v connected to charger
Some gassing while connected to charger
6.99 m-Ohm internal resistance
61% wear life (based on 435EN 475CCA)
371 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (halved current from previous to reduce gassing)
49mA effective charge current
0.67w max effective charge power
1.8-2.1w mains draw
32.48v open circuit (estimated)
50mA open circuit (estimated)

 

[DiyNutJob]

It is now fully understood what are the consequences of gassing. Excessive gassing would be vented out resulting in a permanent loss of water which makes the battery less efficient (electrolyte chemistry being out of the optimum balance). The gasses retained within the battery air space would recombine into water and return to the electrolyte. Since electricity caused the water to go gaseous, it would be logical to deduce that the gasses recombined back into water would produce electricity. The rate of recombining would be slow, and the electricity produced would not have much capacity. The mythical "surface charge" is basically the electricity produced by the gases returning to the electrolyte. The "surface" referred to is in fact the electrolyte surface in contact with the air space. The surface charge produces a higher voltage reading for the battery that would dissipate over time. Any process that depends on the voltage reading would be thrown off track.

A phenomenon observed earlier in the thread, where the battery continued to be charged even when no charger is connected, is in fact the surface charge charging the battery.

Back to the battery: even at minimal charge current, there remain a tiny bit of gassing. This will dissipate eventually, the dropping voltage over the past few readings suggests the surface charge is being depleted. The surface charge acts as a second charger. In effect, the battery is getting more current than what is available at the moment from the physical charger.

Battery state
13.42v stand alone
13.53v connected to charger
Tiny bit of gassing while connected to charger
6.96 m-Ohm internal resistance
62% wear life (based on 435EN 475CCA)
373 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (halved current from previous to reduce gassing)
25mA effective charge current
0.34w max effective charge power
1.5w mains draw
32.45v open circuit
33mA open circuit

 

[DiyNutJob]

The cca peaked at 380 and gyrated below that in a 2 cca range for a few days. This meant that the present charger configuration could do no more for the battery. Increasing the current at the risk of increased gassing will work.

Battery state
13.59v stand alone
13.70v connected to charger
Tiny bit of gassing while connected to charger
6.84 m-Ohm internal resistance
64% wear life (based on 435EN 475CCA)
379 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (no change from previous)
30mA effective charge current
0.41w max effective charge power
1.5w mains draw
32.45v open circuit
36mA open circuit

I decided to simulate how the car charges the battery and see what happens. After around 3 hours, I stopped it to simulate parking up for the day

Battery state
13.84v stand alone
14.18v connected to charger
Good (though not extreme) amount of gassing while connected to charger
6.86 m-Ohm internal resistance
63% wear life (based on 435EN 475CCA)
378 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state
84mA effective charge current
1.19w effective charge power
2.73w mains draw
14.2v open circuit
1500mA open circuit

The simulation was done using 1.5A because some of my diagnostic wires were burning up at 3A. I hadn't planned for playing with high amperage. In the real world, the available amperage would be higher than 3A. But none of these matters because the amount of amps the battery could take was constrained by the feeding voltage. Had the battery been empty of charge, all the available amps would have been taken in by the battery.

The battery was gassing on the supposed non-gassing voltage of 14.2v that cars charge batteries at. This proves gassing is inevitable and a moderate amount is fine. I have been over cautious with my tolerance for gassing. Now I can handle a bit more. The gassing is expected to produce a surface charge that will continue to charge the battery. A sneak peek showed a cca of 383, breaking through the limit observed previously. The battery is currently unconnected in order to dissipate the surface charge.

 

[DiyNutJob]

Dissipating the surface charge also lost me the cca gained. Charging at 14.2v doesn't seem very useful. 380cca appears to be a practical limit of the battery's capacity. While installed in the car, the capacity probably wouldn't go higher because of the 14.2v constraint. But, I am attempting to push it higher while off the car because I know the theoretical capacity is higher, and it's good for desulfation.

Battery state
13.06v stand alone
6.82 m-Ohm internal resistance
64% wear life (based on 435EN 475CCA)
380 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

With the battery rested, high voltage charging was resumed at 50mA reflecting my increased tolerance for gassing. The cca gained was tiny but I should have a bigger gain on the next reading. Contrasting with charging at 14.2V, the internal resistance was lower while being charged, which was a good sign for more cca gains.

Battery state
13.73v stand alone
13.9v connected to charger
Some gassing while connected to charger
6.81 m-Ohm internal resistance
64% wear life (based on 435EN 475CCA)
381 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state
46mA effective charge current
0.64w max effective charge power
1.8 - 2.1w mains draw
32.46v open circuit
54mA open circuit

 

[DiyNutJob]

High voltage charging peaked at 382cca and 6.8mOhm, then nose dived. With my being less concerned with the gassing at the present level, I will follow this dive and see what happens. The charger will be allowed to keep pushing. The battery theory video posted previously observed intermittent voltage dips during charging. I am not getting that but I think it is related to what I am seeing with the CCA dip. My voltage continue to rise or steady.

Battery state
13.78v stand alone
14.19v connected to charger
Some gassing while connected to charger
6.97 m-Ohm internal resistance
61% wear life (based on 435EN 475CCA)
372 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (trimmed current upward to maintain 50mA effective)
50mA effective charge current
0.71w max effective charge power
1.8 - 2.1w mains draw
32.46v open circuit
58mA open circuit

Quote Quote
Report

 

[DiyNutJob]

The dive continues.

Battery state
13.82v stand alone
14.28v connected to charger
Some gassing while connected to charger
7.1 m-Ohm internal resistance
59% wear life (based on 435EN 475CCA)
365 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (no adjustment from previous)
50mA effective charge current
0.71w max effective charge power
1.8 - 2.1w mains draw
32.47v open circuit
57mA open circuit

 

[DiyNutJob]

I could be going down a bottomless pit. The CCA drop doesn't seem to bottom out. The gassing seems cumulative and becoming more than I like. So, I am halving the charging current to 25mA after this reading to reduce gassing. But, I am continuing with the dive.

Battery state
13.9v stand alone
14.47v connected to charger
Excessive gassing while connected to charger
7.34 m-Ohm internal resistance
59% wear life (based on 435EN 475CCA)
353 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (no adjustment from previous)
50mA effective charge current
0.72w max effective charge power
1.8 - 2.1w mains draw
32.53v open circuit
56mA open circuit

Quote Quote

 

[DiyNutJob]

The CCA recovered strongly by a mere change of 25mA charging current! The gassing is a bit on the low side now, giving me room to trim the current up again. But, I am leaving it as is to see what happens next. I expect the CCA to recover some more.

Observation: excessive gassing appears to be caused by the connected voltage being higher than 14.2v

Battery state
13.73v stand alone
13.9v connected to charger
Light gassing while connected to charger
7.04 m-Ohm internal resistance
60% wear life (based on 435EN 475CCA)
368 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (halved current to reduce gassing)
24mA effective charge current
0.33w max effective charge power
1.2 - 1.5w mains draw
31.45v open circuit
30mA open circuit

 

[DiyNutJob]

The CCA did not recover more as hoped. It resumed dropping as expected, caused by the charging. The CCA dipped the most when the connected voltage was higher than 14.2v. The 25mA charging wasn't strong enough to push the connected voltage beyond 14.2v by very much. Eventually, the voltage just bounced up and down around that number. This tells me 25mA is a safe current for unattended permanent trickle charging because it couldn't do much harm.

I decided to pull the plug because the charging just caused the CCA to bounce up and down around 360 and not go anywhere for better or for worse. The final reading is:

Battery state
13.85v stand alone
14.18v connected to charger
Some gassing that seemed neither too much nor too little while connected to charger
7.19 m-Ohm internal resistance
58% wear life (based on 435EN 475CCA)
361 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

Charger state (no adjustment from previous)
24mA effective charge current
0.34w max effective charge power
1.5 - 1.8w mains draw
32.51v open circuit
34mA open circuit


After resting the battery for 3 days, the anticipated CCA recovery was underwhelming.

Battery state
12.98v stand alone
7.03 m-Ohm internal resistance
60% wear life (based on 435EN 475CCA)
369 CCA
Spec: Powerline 075 435EN 45Ah(C20), very old

This session of charging didn't gain anything for the battery. In fact, it lost 10 cca from what was initially achieved. I don't believe the loss is permanent (to be verified). The session did gain knowledge about the 14.2v barrier that will be put to use immediately.

 

[DiyNutJob]

The tiny little battery that helped me pass the MOT is now struggling hard to start the car after a month in the cold. So, I am swapping it out for the next charging session.

Battery state
10.1v stand alone
14.16 m-Ohm internal resistance
24% wear life (based on 340EN 374CCA)
183 CCA
Spec: Lion 063 40Ah EN 340CCA, very old

I believe excessive gassing is caused by the connected voltage being higher than 14.2V. Until the battery reaches that state, I believe both the charging current and voltage can be high. Because the charger is protected by 1A mini fuses (I don't have any higher amperage fuses), I begin the charging at 900mA effective. This will speed up charging tremendously compared to previous sessions. More tricks will follow to deal with the 14.2v gassing problem.

 

[DiyNutJob]

Over did the power! The intent was to not go beyond 14.2V connected. The high power charging punched through that level quicker than anticipated. A new cca upper limit is now established for the battery. The actual limit will be higher. This session gives me a glimpse of how 16V was observed for a battery in the past when perma-connected to a 23v-max, 200mA-max solar panel. High voltage plus sufficient amperage will do it. The solar panel did not cause loss of water to the battery. Nor did 16V affect the car electronics.

Battery state
13.39v stand alone
15.54v connected to charger
Unacceptable amount of gassing while connected to charger
8.79 m-Ohm internal resistance
62% wear life (based on 340EN 374CCA)
294 CCA
Spec: Lion 063 40Ah EN 340CCA, very old

Charger state
879mA effective charge current
13.66w effective charge power
18.8 - 19.1w mains draw
32.39v open circuit
858mA open circuit

The charging has been stopped to allow the surface charge to dissipate and the battery voltage to subside. Charging will resume after that. The plan is to only charge when the unconnected voltage is low and the connected voltage is below 14.2V.

 

[DiyNutJob]

The dissipating surface charge got converted to more CCAs. The dissipation will be assumed over once the CCA stops rising or starts to decline. New CCA upper limit established for the battery.

Battery state
12.89v stand alone
8.64 m-Ohm internal resistance
64% wear life (based on 340EN 374CCA)
300 CCA
Spec: Lion 063 40Ah EN 340CCA, very old

Not currently charging. Waiting for the surface charge dissipation to end. The wait should also reduce the stand alone voltage. Low stand alone voltage is helpful to charging.

 

[DiyNutJob]

After 2 days of resting, the CCA dropped, indicating depletion of the surface charge. The stand alone voltage remained steady, indicating robust stored charge at the read CCA level.

Battery state
12.87v stand alone
8.82 m-Ohm internal resistance
61% wear life (based on 340EN 374CCA)
293 CCA
Spec: Lion 063 40Ah EN 340CCA, very old


After resuming charging at 100mA for a day, a new CCA upper limit is established.

Battery state
13.37v stand alone
13.65v connected to charger
Surprisingly tiny-tiny amount of gassing
8.49 m-Ohm internal resistance
67% wear life (based on 340EN 374CCA)
305 CCA
Spec: Lion 063 40Ah EN 340CCA, very old

Charger state
97mA effective charge current
1.32w effective charge power
2.7w - 3w mains draw
32.47v open circuit
96mA open circuit

Going by the present connected voltage, it will probably take 1 or 2 days before the voltage reaching the 14.2v level where stronger gassing will begin. I hope to get 10 or 20 CCAs more until that moment.