How do I charge a LiFePo4 cell/battery via solar energy?

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#1
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Is it possible to charge LiFePo4 cells or batteries via solar power? Because solar energy is not always stable and LiFePo4 needs a stable current as I understand.
Is there still a way some how to manage this? (perhaps ultracaps as buffer?)

RES

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LT3652 or LTM8062 for larger cells/batteries.
Charges LFP in addition to other types.
Steady current - after reaching charged voltage, its usually a current of C/10 to terminate charging.
The goal is to use the maximimum power (by MPPT) available from the photovoltaic panel.
If don't need MPPT and am able to match the panel to the cell/battery, the Microchip MCP73123/223 linear LFP charger could work.

"Dare to be naïve." - Buckminster Fuller

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Was curious so read Wikipedia about LiFePo4 batteries. Could you point me to a link that says you need a constant charge current?

Cheers,
davef

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BQ24650 from Texas Instruments.
P.S. TI has BQ24210 for a Li-ion cell (solar, linear to 0.8A).

"Dare to be naïve." - Buckminster Fuller

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I am of the opinion you don't need a constant charge current or voltage. Shelf life is longest at 50% charge or ~3.3 volts so if you directly connect the panel and charge a largish battery at C/100, say 10 amp hours 0 to 100ma rates depending on the sun, and stay close to the middle by drawing the same amphours out every night, then you automatically have the longest lifetime with no extra components.

But if you want to get the maximum charge charge cycle from the battery, you do have to limit the upper and lower voltages, e.g. 3.65 and 2.5 per cell.

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I have used the TI BQ24210 to charge a 18650 li-ion battery from a 6v solar panel and it works very well. However the package is a real bitch to hand solder.