An attempt at a brief summary of solar charging ICs for single-cell lithium batteries.
Solar panels provide the most power if you limit the current drawn from them, so a proper solar charger will do MPPT (Maximum Power Point Tracking). In reality, most cheap solar charger ICs imitate this by restricting the current drawn to keep the panel voltage constant (generally around 4.5V).
You probably want to use:
MFN | MFP | Max U (abs) | Max I | Pkg | Price/ea | Source | Datasheet |
---|---|---|---|---|---|---|---|
Consonance | CN3083 | 6V (6.5V) | 600mA | SOP8 | ~£1 | Ebay | [PDF] |
Consonance | CN3082 | 6V (6.5V) | 600mA | SOP8+EP | ~£0.5 | AliExpress | [PDF] |
| | 6V (7V) | 500mA | SOT-23 | ~£0.4 | DigiKey | [PDF] |
Linear | LT3652 | 32V (40V) | 2A | 12-TSSOP+EP | £4-5 | DigiKey | [PDF] |
TI | BQ24040 | 6.8V (32V) | 1A | 10-WFDFN+EP | ~£1 | DigiKey | [PDF] |
Linear | LTC4121 | 40V (43V) | 400mA | 16-QFN+EP | ~£4 | DigiKey | [PDF] |
Linear | LTC4079 | 60V (62V) | 250mA | 10-DFN+EP | ~£4 | DigiKey | [PDF] |
Not a solar charger (USB or simmilar)