David Bowling's Continuous Charging Device

[itsu]

I happen to have a depleted, broken or otherwise defective 12V / 7Ah battery which only holds about 7.2V.
I have used the above mentioned setup (2x 12V / 7Ah batteries in series, across the depleted battery in series with a 12V dc motor) in trying to revive this battery.

It takes a while (10 minutes) before the motor starts turning and keeps on increasing in speed (voltage/current) while the depleted battery voltage keeps decreasing
from 24V to 14V  when i stopped this run due to bedtime.

Overnight this battery hold its voltage to 8.16V, so it looks in a somewhat better shape. 
Guess i can repeat this test with a longer duration to see if i can fully restore this battery this way.
Temperature measurements did not show any in - or decrease during the half an hour test.

Video here:  https://www.youtube.com/watch?v=L1Yu3uk85Ko

Itsu

[itsu]

I made a longer 3.5 hour run today in trying to revive my depleted / no charge holding battery.
I think i gained another volt as it settled down after a few hours resting on 9.78V which is still a far cry from the 12.5V this battery should be able to hold,
but 2.5 volts better then with what i started with (7.2V).

One thing i again (after yesterdays run) noticed is that when taking temperature readings of the + and - leads of the battery, there seems to be a difference of max. 0.7°C
especially during the start / middle period when the voltage and currents are fluctuating heavily.

Lateron it settles down again till about 0.1°C difference which i think falls within the specs of the used temp meters.
I used a laser temp. meter and lateron backed it up with a fixed temp. probe on a multimeter.

Here the table of todays run:

time into the run         + lead temp. °C     - lead temp. °C       Delta °C

00:00                         20.1                     20.5                       0.4
00:20                         19.9                     20.5                       0.6
00:40                         19.7                     20.4                       0.7    <<<<< max.
01:00                         19.1                     19.7                       0.6
01:30                         20.3                     20.7                       0.4
02:00                         20.4                     20.8                       0.4
02:30                         21                       21.1                        0.1
03:00                         20.8                    20.9                        0.1
03:30                         21.2                    21.3                        0.1

Video here:   https://www.youtube.com/watch?v=rcgXGp9q6gU   


I guess i have to confirm in a better way that there is a temp. difference (cooling effect?) during loading of a battery or more specific, of such a depleted / no charge holding battery.


Itsu

[ramset]

Well
that seems unusual.
very nice work itsu ,some have been discussing the test criteria and adding Temp monitoring was being kicked around too [as opposed to spot checking] , Now it seems data logging temp should be mandatory  [checking plus and minus was very smart 


hopefully the arduino will have enuff ability to do this on 4 or 5 batteries during the various automated cycling stages.

very nice indeed .

Chet

PS
I am sure you are aware Duncan will be doing a test when he gets back from his trip to see if he can reproduce his frosty battery event
that would truly be something to see.

[tinman]

Well
that seems unusual.
very nice work itsu ,some have been discussing the test criteria and adding Temp monitoring was being kicked around too [as opposed to spot checking] , Now it seems data logging temp should be mandatory  [checking plus and minus was very smart 


hopefully the arduino will have enuff ability to do this on 4 or 5 batteries during the various automated cycling stages.

very nice indeed .

Chet

PS
I am sure you are aware Duncan will be doing a test when he gets back from his trip to see if he can reproduce his frosty battery event
that would truly be something to see.

[/glow]


Indeed.



Brad

[itsu]

Chet,

yes, that comment from Duncan and others about freezing up etc. triggered me to do these temp. checks.
This morning my depleted battery has settled down to 9.3V, so 2V gain, but nowhere near topcondition 

Itsu