Hoping this might help someone else.
I have made several posts over the last year trying to understand why I have had a few problems keeping batteries in sync with each other in my case 12v batteries in 36v or 48v series string. Many many times people have said you need to test the batteries to confirm there health and I have tried a few things with a 12v inverter and a lamp but I finally bought a battery capacity tester and started testing.
I cant recommend enough you buy one if you are in this situation I grabbed one of these for £33
My plan for each battery is;
4 x 12ah batteries to test
Will keep updating numbers as it goes but
Results for 55ah;
Results for repaired 55ah;
Results for 12ah; (I know these are dead age wise but fully charged, but they quick to test)
Results for repaired 12ah;
I am hoping this will explain my battery voltage issues I see below;
Around 5:45am inverter powers on and we see drain until about 8am ish when my shade goes away and it steadily charges until around 54v (13.5v) then all hell breaks loose and I see some of the batteries start to leap up to 14.8v whilst others 13.8v for example but then my balancers kick in and smooth things out but they cant keep up with the ups and downs as there is draw from the house.
So in many many days time after many many hours I can hopefully pair up my good batteries assuming I have some and see a much smother looking line.
I have made several posts over the last year trying to understand why I have had a few problems keeping batteries in sync with each other in my case 12v batteries in 36v or 48v series string. Many many times people have said you need to test the batteries to confirm there health and I have tried a few things with a 12v inverter and a lamp but I finally bought a battery capacity tester and started testing.
I cant recommend enough you buy one if you are in this situation I grabbed one of these for £33
My plan for each battery is;
- Charge the battery with a 7 stage charger
- Test using the capacity tester 10amp pull for 55ah and 2.5amp for 12ah cut off at 12v arguably around 50% DoD
- Record AH
- Record run time
- Charge the battery again
- Record charge time
- Record WH going in
- Roughly figure the health of the battery peukert number and use that as a good/bad indicator using this website
- Run a repair on the battery
- Retest again
4 x 12ah batteries to test
Will keep updating numbers as it goes but
Results for 55ah;
Battery 55AH | AH | Time | Charge Start | Charge End | Charge Time | Charge WH Start | Charge WH Finish | WH In | Peukert |
B1 | 23.38 | 02:20:16 | 14:33:07 | 20:45:07 | 06:12:00 | 4 | 543 | 539 | 1.07 |
B2 | 9.39 | 00:56:20 | 20:48:52 | 23:47:52 | 02:59:00 | 543 | 778 | 235 | 1.45 |
Results for repaired 55ah;
Battery Repaired | AH | Time | Charge Start | Charge End | Charge Time | Charge WH Start | Charge WH Finish | WH In | Peukert | AH Gain | % Increase |
B1 | 23.33 | 02:20:03 | 15:45:22 | 21:49:47 | 06:04:25 | 120 | 666 | 546 | 1.07 | -0.05 | -0.21 |
Results for 12ah; (I know these are dead age wise but fully charged, but they quick to test)
Battery 12AH | AH | Time | Charge Start | Charge End | Charge Time | Charge WH Start | Charge WH Finish | WH In | Peukert |
S1 | 1.02 | 00:24:15 | 20:09:57 | 20:44:42 | 00:34:45 | 0 | 22 | 22 | 2.9 |
S2 | 2.5 | 01:00:05 | 20:50:57 | 21:51:27 | 01:00:30 | 22 | 90 | 68 | 1.9 |
S3 | 0 | 00:00:03 | 22:51:27 | 23:01:05 | 00:09:38 | 90 | 91 | 1 | 10 |
S4 | 1.45 | 00:34:44 | 23:10:27 | 23:59:59 | 00:49:32 | 92 | 125 | 33 | 2.6 |
Results for repaired 12ah;
Battery Repaired | AH | Time | Charge Start | Charge End | Charge Time | Charge WH Start | Charge WH Finish | WH In | Peukert | AH Gain | % Increase |
S1 | 1.43 | 00:34:26 | 15:39:22 | 16:30:07 | 00:50:45 | 91 | 125 | 34 | 2.6 | 0.41 | 40 |
S2 | 3.47 | 01:23:20 | 17:13:12 | 18:24:47 | 01:11:35 | 128 | 204 | 76 | 1.6 | 0.97 | 39 |
S3 | 0.61 | 00:14:39 | 18:25:07 | 18:51:22 | 00:26:15 | 204 | 218 | 14 | 3.4 | 0.6 | 6000 |
I am hoping this will explain my battery voltage issues I see below;
Around 5:45am inverter powers on and we see drain until about 8am ish when my shade goes away and it steadily charges until around 54v (13.5v) then all hell breaks loose and I see some of the batteries start to leap up to 14.8v whilst others 13.8v for example but then my balancers kick in and smooth things out but they cant keep up with the ups and downs as there is draw from the house.
So in many many days time after many many hours I can hopefully pair up my good batteries assuming I have some and see a much smother looking line.
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