Voltage for fully charged EG4?
- Thread starter Aakelley
- Start date
Jack Rabbit Off Grid
Solar Enthusiast
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- Sep 6, 2021
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- 478
I hope someone comes up with a way to hook an iPad up to these. I don’t want to buy or even own another PC.
Aakelley
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- Feb 3, 2022
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I had to dig out an old netbook.
sunshine_eggo
Happy Breffast!
There you go!
Equal voltages doesn't mean balanced. It mean equal voltages. BALANCE refers to all cells being at the same state of charge. The only time you can be 100% certain of the state of charge of a cell is at full, 3.65V or empty, 2.5V. Equal voltages in the operating range of the cells tells you nothing.
A "balanced" battery typically means that all cells are at the same state of charge when the battery is charged to 100% SoC.
Now you know why you can't charge higher. You have runners due to many cells being at different states of charge. They probably aren't that far off - probably not more than the 1% mentioned earlier in the thread.
Simply charging and discharging is going to take forever to balance them. You need to hold the pack at the lowest voltage that will still accept current and enable balancing of the high cells.
Equal voltages doesn't mean balanced. It mean equal voltages. BALANCE refers to all cells being at the same state of charge. The only time you can be 100% certain of the state of charge of a cell is at full, 3.65V or empty, 2.5V. Equal voltages in the operating range of the cells tells you nothing.
A "balanced" battery typically means that all cells are at the same state of charge when the battery is charged to 100% SoC.
Now you know why you can't charge higher. You have runners due to many cells being at different states of charge. They probably aren't that far off - probably not more than the 1% mentioned earlier in the thread.
Simply charging and discharging is going to take forever to balance them. You need to hold the pack at the lowest voltage that will still accept current and enable balancing of the high cells.
Aakelley
New Member
- Joined
- Feb 3, 2022
- Messages
- 140
So I’ve got two options to charge. The 40 amp high frequency charger I got with the batteries. And the growatt, which I had left hooked up for 4-5 days and limited to only 10 amps. Seems I need something else?
sunshine_eggo
Happy Breffast!
The Growatt chargers are goofy. They have an ON voltage and an OFF voltage. If between the voltages, it won't charge at all.
10A is better than 40A.
If it's this guy:
Set #12 to the max, 25.6V
Set #13 to 29.2V
You might have to periodically discharge it to 25.6V to get the charger to resume after a BMS disconnect.
Is there a way you could set a 9A load? That way the net current to the battery is ~1A. It would make for a great automated "mini-cycler" where only 1A is going to the battery, but there's 9A to pull it below 25.6V when the BMS disconnects.
10A is better than 40A.
If it's this guy:
Set #12 to the max, 25.6V
Set #13 to 29.2V
You might have to periodically discharge it to 25.6V to get the charger to resume after a BMS disconnect.
Is there a way you could set a 9A load? That way the net current to the battery is ~1A. It would make for a great automated "mini-cycler" where only 1A is going to the battery, but there's 9A to pull it below 25.6V when the BMS disconnects.
sunshine_eggo
Happy Breffast!
Would also disconnect the data cable.
