WhiteEagle
New Member
- Joined
- Jan 31, 2022
- Messages
- 7
Hi all,
first message here, thank you a ton for sharing your precious knowledge.
I have a little 150W 18V solar panel (foldable Dokio), and I want to use it to charge lithium-ion 3.7V cells (mostly 18650) during daylight. I am wondering what would be the best way to do so, with good efficiency, and as little hardware as possible.
The most naive way would be to do so :
PV Panel -> PV Charge Controller -> 12V Buffer Battery -> Li-Ion Charger -> Li-Ion Cells
However, this arrangement would require a 12V Buffer Battery, and 2 charge controllers around.
If it is technically doable, I would like to stick to as few parts as possible. Again, my main goal is to recharge 18650 Li-Cells from the PV panel during daylight, and this intermediate 12V buffer battery feels redundant.
I already own good a quality 4-cells Li-Ion charger, and the PV Charge Controller that is included in the Dokio package (probably a cheap chinese PWM based current limiter). The manual of this Charge Controllers says something like "Don't connect anything to the 12V output before connecting the 12V buffer battery". Well ...
I could certainly use a 3S arrangement of 18650 Li-Ion cells as the 12V buffer battery, and the charge controller would charge them. I would also use, further, a Li-Ion cells charger to charge more cells.
But in this case, if I understand correctly, the 12V PV Charge Controller will need to charge the 3S cells directly, as a 12V buffer. There is no way it could charge them through a BMS so that cells remains balanced and in-spec. Therefore, I am concerned that the cells allocated to the 12V buffer battery would not be easy to manage and swap to be used in my tools, lamps etc.
I could also put a dedicated 12V buffer battery (Lead/Acid or LiFePo or LiIon), dedicated because the cells used there would not be extracted to be used in tools. Again, since I just want to charge my 18650 cells during daylight, this intermediate redundant battery feels suboptimal for my use case.
In your opinion, what would be the smartest way to charge my Li-Ion cells during daylight in the most direct and efficient way, with as little hardware as possible.
Thank you all
first message here, thank you a ton for sharing your precious knowledge.
I have a little 150W 18V solar panel (foldable Dokio), and I want to use it to charge lithium-ion 3.7V cells (mostly 18650) during daylight. I am wondering what would be the best way to do so, with good efficiency, and as little hardware as possible.
The most naive way would be to do so :
PV Panel -> PV Charge Controller -> 12V Buffer Battery -> Li-Ion Charger -> Li-Ion Cells
However, this arrangement would require a 12V Buffer Battery, and 2 charge controllers around.
If it is technically doable, I would like to stick to as few parts as possible. Again, my main goal is to recharge 18650 Li-Cells from the PV panel during daylight, and this intermediate 12V buffer battery feels redundant.
I already own good a quality 4-cells Li-Ion charger, and the PV Charge Controller that is included in the Dokio package (probably a cheap chinese PWM based current limiter). The manual of this Charge Controllers says something like "Don't connect anything to the 12V output before connecting the 12V buffer battery". Well ...
I could certainly use a 3S arrangement of 18650 Li-Ion cells as the 12V buffer battery, and the charge controller would charge them. I would also use, further, a Li-Ion cells charger to charge more cells.
But in this case, if I understand correctly, the 12V PV Charge Controller will need to charge the 3S cells directly, as a 12V buffer. There is no way it could charge them through a BMS so that cells remains balanced and in-spec. Therefore, I am concerned that the cells allocated to the 12V buffer battery would not be easy to manage and swap to be used in my tools, lamps etc.
I could also put a dedicated 12V buffer battery (Lead/Acid or LiFePo or LiIon), dedicated because the cells used there would not be extracted to be used in tools. Again, since I just want to charge my 18650 cells during daylight, this intermediate redundant battery feels suboptimal for my use case.
In your opinion, what would be the smartest way to charge my Li-Ion cells during daylight in the most direct and efficient way, with as little hardware as possible.
Thank you all
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